实现epub的懒加载(未经广泛测试)

app/src/main/assets/epub/chapter.html

@@ -7,11 +7,6 @@
     <link href="../Styles/main.css" type="text/css" rel="stylesheet"/>
 </head>
 <body>
-<!--<div class="logo">
-    <img alt="" class="logo" src="../Images/logo.png"/>
-</div>-->
-<br/>
-<br/>
 <h2 class="head">{title}</h2>
 {content}
 </body>

app/src/main/java/io/legado/app/help/http/cronet/AbsCallBack.kt

@@ -60,11 +60,10 @@ abstract class AbsCallBack(
     }
 
 
-    //UrlResponseInfo可能为null
     override fun onResponseStarted(request: UrlRequest, info: UrlResponseInfo) {
         this.mResponse = responseFromResponse(this.mResponse, info)
         //打印协议，用于调试
-        DebugLog.i(javaClass.name, info.negotiatedProtocol)
+        DebugLog.i(javaClass.simpleName, "start[${info.negotiatedProtocol}]${info.url}")
         if (eventListener != null) {
             eventListener.responseHeadersEnd(mCall, this.mResponse)
             eventListener.responseBodyStart(mCall)
@@ -108,6 +107,7 @@ abstract class AbsCallBack(
             buffer.asResponseBody(contentType)
         val newRequest = originalRequest.newBuilder().url(info.url).build()
         this.mResponse = this.mResponse.newBuilder().body(responseBody).request(newRequest).build()
+        DebugLog.i(javaClass.simpleName, "end[${info.negotiatedProtocol}]${info.url}")
 
         eventListener?.callEnd(mCall)
         if (responseCallback != null) {

app/src/main/java/io/legado/app/model/localBook/EpubFile.kt

@@ -2,6 +2,7 @@ package io.legado.app.model.localBook
 
 import android.graphics.Bitmap
 import android.graphics.BitmapFactory
+import android.net.Uri
 import android.text.TextUtils
 import io.legado.app.data.entities.Book
 import io.legado.app.data.entities.BookChapter
@@ -10,6 +11,7 @@ import me.ag2s.epublib.domain.EpubBook
 import me.ag2s.epublib.domain.Resource
 import me.ag2s.epublib.domain.TOCReference
 import me.ag2s.epublib.epub.EpubReader
+import me.ag2s.epublib.zip.ZipFile
 import org.jsoup.Jsoup
 import org.jsoup.nodes.Element
 import org.jsoup.select.Elements
@@ -101,9 +103,16 @@ class EpubFile(var book: Book) {
     /*重写epub文件解析代码，直接读出压缩包文件生成Resources给epublib，这样的好处是可以逐一修改某些文件的格式错误*/
     private fun readEpub(): EpubBook? {
         try {
-            val bis = LocalBook.getBookInputStream(book)
-            //通过懒加载读取epub
-            return EpubReader().readEpub(bis, "utf-8")
+            val uri = Uri.parse(book.bookUrl)
+            return if (uri.isContentScheme()) {
+                //通过懒加载读取epub
+                EpubReader().readEpubLazy(ZipFile(appCtx, uri), "utf-8")
+            } else {
+                val bis = LocalBook.getBookInputStream(book)
+                EpubReader().readEpub(bis, "utf-8")
+            }
+
+
         } catch (e: Exception) {
             e.printOnDebug()
         }

epublib/src/main/java/me/ag2s/epublib/domain/EpubResourceProvider.java

@@ -1,32 +1,40 @@
 package me.ag2s.epublib.domain;
 
+import android.content.Context;
+import android.net.Uri;
+
 import java.io.IOException;
 import java.io.InputStream;
-import java.util.zip.ZipEntry;
-import java.util.zip.ZipFile;
+
+import me.ag2s.epublib.zip.ZipEntry;
+import me.ag2s.epublib.zip.ZipFile;
 
 /**
  * @author jake
  */
 public class EpubResourceProvider implements LazyResourceProvider {
 
-  private final String epubFilename;
+  private final Context context;
+  private final Uri uri;
 
   /**
-   * @param epubFilename the file name for the epub we're created from.
+   * @param context
+   * @param uri
    */
-  public EpubResourceProvider(String epubFilename) {
-    this.epubFilename = epubFilename;
+  public EpubResourceProvider(Context context, Uri uri) {
+    this.context = context;
+    this.uri = uri;
   }
 
+
   @Override
   public InputStream getResourceStream(String href) throws IOException {
-    ZipFile zipFile = new ZipFile(epubFilename);
+    ZipFile zipFile = new ZipFile(context, uri);
     ZipEntry zipEntry = zipFile.getEntry(href);
     if (zipEntry == null) {
       zipFile.close();
       throw new IllegalStateException(
-          "Cannot find entry " + href + " in epub file " + epubFilename);
+              "Cannot find entry " + href + " in epub file " + uri.toString());
     }
     return new ResourceInputStream(zipFile.getInputStream(zipEntry), zipFile);
   }

epublib/src/main/java/me/ag2s/epublib/domain/ResourceInputStream.java

@@ -3,7 +3,8 @@ package me.ag2s.epublib.domain;
 import java.io.FilterInputStream;
 import java.io.IOException;
 import java.io.InputStream;
-import java.util.zip.ZipFile;
+
+import me.ag2s.epublib.zip.ZipFile;
 
 /**
  * A wrapper class for closing a ZipFile object when the InputStream derived

epublib/src/main/java/me/ag2s/epublib/epub/EpubReader.java

@@ -9,8 +9,6 @@ import java.io.IOException;
 import java.io.InputStream;
 import java.util.Arrays;
 import java.util.List;
-import java.util.zip.ZipFile;
-import java.util.zip.ZipInputStream;
 
 import me.ag2s.epublib.Constants;
 import me.ag2s.epublib.domain.EpubBook;
@@ -20,6 +18,8 @@ import me.ag2s.epublib.domain.Resource;
 import me.ag2s.epublib.domain.Resources;
 import me.ag2s.epublib.util.ResourceUtil;
 import me.ag2s.epublib.util.StringUtil;
+import me.ag2s.epublib.zip.ZipFile;
+import me.ag2s.epublib.zip.ZipInputStream;
 
 /**
  * Reads an epub file.

epublib/src/main/java/me/ag2s/epublib/epub/EpubWriter.java

@@ -9,14 +9,14 @@ import java.io.InputStream;
 import java.io.OutputStream;
 import java.io.OutputStreamWriter;
 import java.io.Writer;
-import java.util.zip.CRC32;
-import java.util.zip.ZipEntry;
-import java.util.zip.ZipOutputStream;
 
 import me.ag2s.epublib.domain.EpubBook;
 import me.ag2s.epublib.domain.MediaTypes;
 import me.ag2s.epublib.domain.Resource;
 import me.ag2s.epublib.util.IOUtil;
+import me.ag2s.epublib.zip.CRC32;
+import me.ag2s.epublib.zip.ZipEntry;
+import me.ag2s.epublib.zip.ZipOutputStream;
 
 /**
  * Generates an epub file. Not thread-safe, single use object.

epublib/src/main/java/me/ag2s/epublib/epub/NCXDocumentV2.java

@@ -14,8 +14,6 @@ import java.io.UnsupportedEncodingException;
 import java.net.URLDecoder;
 import java.util.ArrayList;
 import java.util.List;
-import java.util.zip.ZipEntry;
-import java.util.zip.ZipOutputStream;
 
 import me.ag2s.epublib.Constants;
 import me.ag2s.epublib.domain.Author;
@@ -27,6 +25,8 @@ import me.ag2s.epublib.domain.TOCReference;
 import me.ag2s.epublib.domain.TableOfContents;
 import me.ag2s.epublib.util.ResourceUtil;
 import me.ag2s.epublib.util.StringUtil;
+import me.ag2s.epublib.zip.ZipEntry;
+import me.ag2s.epublib.zip.ZipOutputStream;
 
 /**
  * Writes the ncx document as defined by namespace http://www.daisy.org/z3986/2005/ncx/

epublib/src/main/java/me/ag2s/epublib/epub/ResourcesLoader.java

@@ -7,10 +7,6 @@ import java.util.ArrayList;
 import java.util.Collection;
 import java.util.Enumeration;
 import java.util.List;
-import java.util.zip.ZipEntry;
-import java.util.zip.ZipException;
-import java.util.zip.ZipFile;
-import java.util.zip.ZipInputStream;
 
 import me.ag2s.epublib.domain.EpubResourceProvider;
 import me.ag2s.epublib.domain.LazyResource;
@@ -21,6 +17,10 @@ import me.ag2s.epublib.domain.Resource;
 import me.ag2s.epublib.domain.Resources;
 import me.ag2s.epublib.util.CollectionUtil;
 import me.ag2s.epublib.util.ResourceUtil;
+import me.ag2s.epublib.zip.ZipEntry;
+import me.ag2s.epublib.zip.ZipException;
+import me.ag2s.epublib.zip.ZipFile;
+import me.ag2s.epublib.zip.ZipInputStream;
 
 
 /**
@@ -51,7 +51,7 @@ public class ResourcesLoader {
                                           List<MediaType> lazyLoadedTypes) throws IOException {
 
         LazyResourceProvider resourceProvider =
-                new EpubResourceProvider(zipFile.getName());
+                new EpubResourceProvider(zipFile.getContext(), zipFile.getUri());
 
         Resources result = new Resources();
         Enumeration<? extends ZipEntry> entries = zipFile.entries();

epublib/src/main/java/me/ag2s/epublib/util/ResourceUtil.java

@@ -10,8 +10,6 @@ import java.io.IOException;
 import java.io.InputStream;
 import java.io.Reader;
 import java.io.UnsupportedEncodingException;
-import java.util.zip.ZipEntry;
-import java.util.zip.ZipInputStream;
 
 import javax.xml.parsers.DocumentBuilder;
 
@@ -20,6 +18,8 @@ import me.ag2s.epublib.domain.MediaType;
 import me.ag2s.epublib.domain.MediaTypes;
 import me.ag2s.epublib.domain.Resource;
 import me.ag2s.epublib.epub.EpubProcessorSupport;
+import me.ag2s.epublib.zip.ZipEntry;
+import me.ag2s.epublib.zip.ZipInputStream;
 
 /**
  * Various resource utility methods

epublib/src/main/java/me/ag2s/epublib/zip/Adler32.java

@@ -0,0 +1,197 @@
+/* Adler32.java - Computes Adler32 data checksum of a data stream
+   Copyright (C) 1999, 2000, 2001 Free Software Foundation, Inc.
+
+This file is part of GNU Classpath.
+
+GNU Classpath is free software; you can redistribute it and/or modify
+it under the terms of the GNU General Public License as published by
+the Free Software Foundation; either version 2, or (at your option)
+any later version.
+
+GNU Classpath is distributed in the hope that it will be useful, but
+WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+General Public License for more details.
+
+You should have received a copy of the GNU General Public License
+along with GNU Classpath; see the file COPYING.  If not, write to the
+Free Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
+02111-1307 USA.
+
+Linking this library statically or dynamically with other modules is
+making a combined work based on this library.  Thus, the terms and
+conditions of the GNU General Public License cover the whole
+combination.
+
+As a special exception, the copyright holders of this library give you
+permission to link this library with independent modules to produce an
+executable, regardless of the license terms of these independent
+modules, and to copy and distribute the resulting executable under
+terms of your choice, provided that you also meet, for each linked
+independent module, the terms and conditions of the license of that
+module.  An independent module is a module which is not derived from
+or based on this library.  If you modify this library, you may extend
+this exception to your version of the library, but you are not
+obligated to do so.  If you do not wish to do so, delete this
+exception statement from your version. */
+
+package me.ag2s.epublib.zip;
+
+/*
+ * Written using on-line Java Platform 1.2 API Specification, as well
+ * as "The Java Class Libraries", 2nd edition (Addison-Wesley, 1998).
+ * The actual Adler32 algorithm is taken from RFC 1950.
+ * Status:  Believed complete and correct.
+ */
+
+/**
+ * Computes Adler32 checksum for a stream of data. An Adler32
+ * checksum is not as reliable as a CRC32 checksum, but a lot faster to
+ * compute.
+ * <p>
+ * The specification for Adler32 may be found in RFC 1950.
+ * (ZLIB Compressed Data Format Specification version 3.3)
+ * <p>
+ * <p>
+ * From that document:
+ * <p>
+ * "ADLER32 (Adler-32 checksum)
+ * This contains a checksum value of the uncompressed data
+ * (excluding any dictionary data) computed according to Adler-32
+ * algorithm. This algorithm is a 32-bit extension and improvement
+ * of the Fletcher algorithm, used in the ITU-T X.224 / ISO 8073
+ * standard.
+ * <p>
+ * Adler-32 is composed of two sums accumulated per byte: s1 is
+ * the sum of all bytes, s2 is the sum of all s1 values. Both sums
+ * are done modulo 65521. s1 is initialized to 1, s2 to zero.  The
+ * Adler-32 checksum is stored as s2*65536 + s1 in most-
+ * significant-byte first (network) order."
+ * <p>
+ * "8.2. The Adler-32 algorithm
+ * <p>
+ * The Adler-32 algorithm is much faster than the CRC32 algorithm yet
+ * still provides an extremely low probability of undetected errors.
+ * <p>
+ * The modulo on unsigned long accumulators can be delayed for 5552
+ * bytes, so the modulo operation time is negligible.  If the bytes
+ * are a, b, c, the second sum is 3a + 2b + c + 3, and so is position
+ * and order sensitive, unlike the first sum, which is just a
+ * checksum.  That 65521 is prime is important to avoid a possible
+ * large class of two-byte errors that leave the check unchanged.
+ * (The Fletcher checksum uses 255, which is not prime and which also
+ * makes the Fletcher check insensitive to single byte changes 0 <->
+ * 255.)
+ * <p>
+ * The sum s1 is initialized to 1 instead of zero to make the length
+ * of the sequence part of s2, so that the length does not have to be
+ * checked separately. (Any sequence of zeroes has a Fletcher
+ * checksum of zero.)"
+ *
+ * @author John Leuner, Per Bothner
+ * @see InflaterInputStream
+ * @see DeflaterOutputStream
+ * @since JDK 1.1
+ */
+public class Adler32 implements Checksum {
+
+    /**
+     * largest prime smaller than 65536
+     */
+    private static final int BASE = 65521;
+
+    private int checksum; //we do all in int.
+
+    //Note that java doesn't have unsigned integers,
+    //so we have to be careful with what arithmetic
+    //we do. We return the checksum as a long to
+    //avoid sign confusion.
+
+    /**
+     * Creates a new instance of the <code>Adler32</code> class.
+     * The checksum starts off with a value of 1.
+     */
+    public Adler32() {
+        reset();
+    }
+
+    /**
+     * Resets the Adler32 checksum to the initial value.
+     */
+    public void reset() {
+        checksum = 1; //Initialize to 1
+    }
+
+    /**
+     * Updates the checksum with the byte b.
+     *
+     * @param bval the data value to add. The high byte of the int is ignored.
+     */
+    public void update(int bval) {
+        //We could make a length 1 byte array and call update again, but I
+        //would rather not have that overhead
+        int s1 = checksum & 0xffff;
+        int s2 = checksum >>> 16;
+
+        s1 = (s1 + (bval & 0xFF)) % BASE;
+        s2 = (s1 + s2) % BASE;
+
+        checksum = (s2 << 16) + s1;
+    }
+
+    /**
+     * Updates the checksum with the bytes taken from the array.
+     *
+     * @param buffer an array of bytes
+     */
+    public void update(byte[] buffer) {
+        update(buffer, 0, buffer.length);
+    }
+
+    /**
+     * Updates the checksum with the bytes taken from the array.
+     *
+     * @param buf an array of bytes
+     * @param off the start of the data used for this update
+     * @param len the number of bytes to use for this update
+     */
+    public void update(byte[] buf, int off, int len) {
+        //(By Per Bothner)
+        int s1 = checksum & 0xffff;
+        int s2 = checksum >>> 16;
+
+        while (len > 0) {
+            // We can defer the modulo operation:
+            // s1 maximally grows from 65521 to 65521 + 255 * 3800
+            // s2 maximally grows by 3800 * median(s1) = 2090079800 < 2^31
+            int n = 3800;
+            if (n > len)
+                n = len;
+            len -= n;
+            while (--n >= 0) {
+                s1 = s1 + (buf[off++] & 0xFF);
+                s2 = s2 + s1;
+            }
+            s1 %= BASE;
+            s2 %= BASE;
+        }
+
+    /*Old implementation, borrowed from somewhere:
+    int n;
+    
+    while (len-- > 0) {
+
+      s1 = (s1 + (bs[offset++] & 0xff)) % BASE; 
+      s2 = (s2 + s1) % BASE;
+    }*/
+
+        checksum = (s2 << 16) | s1;
+    }
+
+    /**
+     * Returns the Adler32 data checksum computed so far.
+     */
+    public long getValue() {
+        return (long) checksum & 0xffffffffL;
+    }
+}

epublib/src/main/java/me/ag2s/epublib/zip/AndroidRandomReadableFile.java

@@ -0,0 +1,368 @@
+package me.ag2s.epublib.zip;
+
+import android.content.Context;
+import android.net.Uri;
+import android.os.ParcelFileDescriptor;
+import android.system.ErrnoException;
+import android.system.OsConstants;
+
+import androidx.annotation.NonNull;
+
+import java.io.Closeable;
+import java.io.DataInput;
+import java.io.DataInputStream;
+import java.io.EOFException;
+import java.io.FileDescriptor;
+import java.io.FileInputStream;
+import java.io.FileNotFoundException;
+import java.io.IOException;
+import java.nio.ByteBuffer;
+import java.nio.ByteOrder;
+import java.nio.channels.FileChannel;
+
+public class AndroidRandomReadableFile implements DataInput, Closeable {
+    private ParcelFileDescriptor pfd;
+    private FileInputStream fis;
+    private DataInputStream dis;
+    public long pos = 0;
+
+    public AndroidRandomReadableFile(@NonNull Context context, @NonNull Uri treeUri) throws FileNotFoundException {
+        try {
+            pfd = context.getContentResolver().openFileDescriptor(treeUri, "r");
+            fis = new FileInputStream(pfd.getFileDescriptor());
+            dis = new DataInputStream(fis);
+        } catch (FileNotFoundException e) {
+            throw e;
+        }
+    }
+
+    public final FileDescriptor getFD() {
+        return pfd.getFileDescriptor();
+    }
+
+    public final FileChannel getChannel() {
+        if (fis == null || pos != getPos()) {
+            fis = new FileInputStream(pfd.getFileDescriptor());
+        }
+        return fis.getChannel();
+    }
+
+    public final FileInputStream getFileInputStream() {
+        if (fis == null || pos != getPos()) {
+            fis = new FileInputStream(pfd.getFileDescriptor());
+        }
+        return fis;
+    }
+
+    public int read() throws IOException {
+        byte[] b = new byte[1];
+        return (read(b, 0, 1) != -1) ? b[0] & 0xff : -1;
+    }
+
+    public int read(byte[] b) {
+        try {
+            return read(b, 0, b.length);
+        } catch (IOException e) {
+            e.printStackTrace();
+            return -1;
+        }
+    }
+
+    public int read(byte[] b, int off, int len) throws IOException {
+        try {
+            return android.system.Os.read(pfd.getFileDescriptor(), b, off, len);
+        } catch (Exception e) {
+            return -1;
+        }
+    }
+
+
+    private void syncInputStream() {
+        fis = new FileInputStream(pfd.getFileDescriptor());
+        dis = new DataInputStream(fis);
+    }
+
+
+    public void seek(long pos) throws IOException {
+        try {
+            android.system.Os.lseek(pfd.getFileDescriptor(), pos, OsConstants.SEEK_SET);
+        } catch (Exception e) {
+            throw new IOException(e);
+        }
+
+    }
+
+    public long length() throws IOException {
+        try {
+            return android.system.Os.lseek(pfd.getFileDescriptor(), 0, OsConstants.SEEK_END);
+        } catch (Exception e) {
+            throw new IOException(e);
+        }
+
+    }
+
+    public long getPos() {
+        try {
+            return android.system.Os.lseek(pfd.getFileDescriptor(), 0, OsConstants.SEEK_CUR);
+        } catch (Exception e) {
+            return -1;
+        }
+
+    }
+
+    @Override
+    public void readFully(byte[] b) throws IOException {
+        try {
+            android.system.Os.read(pfd.getFileDescriptor(), b, 0, b.length);
+        } catch (ErrnoException e) {
+            e.printStackTrace();
+        }
+
+
+    }
+
+    @Override
+    public void readFully(byte[] b, int off, int len) throws IOException {
+        try {
+            android.system.Os.read(pfd.getFileDescriptor(), b, off, len);
+            //syncInputStream();
+        } catch (ErrnoException e) {
+            throw new IOException(e);
+        }
+    }
+
+    @Override
+    public int skipBytes(int n) throws IOException {
+        try {
+            byte[] b = new byte[n];
+            return android.system.Os.read(pfd.getFileDescriptor(), b, 0, b.length);
+        } catch (Exception e) {
+            return -1;
+        }
+
+    }
+
+    @Override
+    public boolean readBoolean() throws IOException {
+        int ch = this.read();
+        if (ch < 0)
+            throw new EOFException();
+        return (ch != 0);
+
+    }
+
+    @Override
+    public byte readByte() throws IOException {
+        int ch = this.read();
+        if (ch < 0)
+            throw new EOFException();
+        return (byte) (ch);
+    }
+
+
+    @Override
+    public int readUnsignedByte() throws IOException {
+        int ch = this.read();
+        if (ch < 0)
+            throw new EOFException();
+        return ch;
+    }
+
+    private final byte[] readBuffer = new byte[8];
+
+    @Override
+    public short readShort() throws IOException {
+        readFully(readBuffer, 0, 2);
+        return ByteBuffer.wrap(readBuffer).order(ByteOrder.BIG_ENDIAN).asShortBuffer().get();
+    }
+
+    @Override
+    public int readUnsignedShort() throws IOException {
+        readFully(readBuffer, 0, 2);
+        return ByteBuffer.wrap(readBuffer).order(ByteOrder.BIG_ENDIAN).asShortBuffer().get() & 0xffff;
+    }
+
+    @Override
+    public char readChar() throws IOException {
+        readFully(readBuffer, 0, 2);
+        return (char) ByteBuffer.wrap(readBuffer).order(ByteOrder.BIG_ENDIAN).asShortBuffer().get();
+    }
+
+    @Override
+    public int readInt() throws IOException {
+        readFully(readBuffer, 0, 4);
+        return ByteBuffer.wrap(readBuffer).order(ByteOrder.BIG_ENDIAN).asIntBuffer().get();
+    }
+
+    @Override
+    public long readLong() throws IOException {
+        readFully(readBuffer, 0, 8);
+        return (((long) readBuffer[0] << 56) +
+                ((long) (readBuffer[1] & 255) << 48) +
+                ((long) (readBuffer[2] & 255) << 40) +
+                ((long) (readBuffer[3] & 255) << 32) +
+                ((long) (readBuffer[4] & 255) << 24) +
+                ((readBuffer[5] & 255) << 16) +
+                ((readBuffer[6] & 255) << 8) +
+                ((readBuffer[7] & 255) << 0));
+    }
+
+    @Override
+    public float readFloat() throws IOException {
+        return Float.intBitsToFloat(readInt());
+    }
+
+    @Override
+    public double readDouble() throws IOException {
+        return Double.longBitsToDouble(readLong());
+    }
+
+    private char[] lineBuffer;
+
+    @Deprecated
+    @Override
+    public String readLine() throws IOException {
+        char[] buf = lineBuffer;
+
+        if (buf == null) {
+            buf = lineBuffer = new char[128];
+        }
+
+        int room = buf.length;
+        int offset = 0;
+        int c;
+
+        loop:
+        while (true) {
+            switch (c = this.read()) {
+                case -1:
+                case '\n':
+                    break loop;
+
+                case '\r':
+                    int c2 = this.read();
+                    break loop;
+
+                default:
+                    if (--room < 0) {
+                        buf = new char[offset + 128];
+                        room = buf.length - offset - 1;
+                        System.arraycopy(lineBuffer, 0, buf, 0, offset);
+                        lineBuffer = buf;
+                    }
+                    buf[offset++] = (char) c;
+                    break;
+            }
+        }
+        if ((c == -1) && (offset == 0)) {
+            return null;
+        }
+        return String.copyValueOf(buf, 0, offset);
+    }
+
+    @Override
+    public String readUTF() throws IOException {
+        if (pos != getPos()) {
+            syncInputStream();
+        }
+        return dis.readUTF();
+    }
+
+//    public final static String readUTF(DataInput in) throws IOException {
+//        int utflen = in.readUnsignedShort();
+//        byte[] bytearr = null;
+//        char[] chararr = null;
+//        if (in instanceof DataInputStream) {
+//            DataInputStream dis = (DataInputStream)in;
+//            if (dis.bytearr.length < utflen){
+//                dis.bytearr = new byte[utflen*2];
+//                dis.chararr = new char[utflen*2];
+//            }
+//            chararr = dis.chararr;
+//            bytearr = dis.bytearr;
+//        } else {
+//            bytearr = new byte[utflen];
+//            chararr = new char[utflen];
+//        }
+//
+//        int c, char2, char3;
+//        int count = 0;
+//        int chararr_count=0;
+//
+//        in.readFully(bytearr, 0, utflen);
+//
+//        while (count < utflen) {
+//            c = (int) bytearr[count] & 0xff;
+//            if (c > 127) break;
+//            count++;
+//            chararr[chararr_count++]=(char)c;
+//        }
+//
+//        while (count < utflen) {
+//            c = (int) bytearr[count] & 0xff;
+//            switch (c >> 4) {
+//                case 0: case 1: case 2: case 3: case 4: case 5: case 6: case 7:
+//                    /* 0xxxxxxx*/
+//                    count++;
+//                    chararr[chararr_count++]=(char)c;
+//                    break;
+//                case 12: case 13:
+//                    /* 110x xxxx   10xx xxxx*/
+//                    count += 2;
+//                    if (count > utflen)
+//                        throw new UTFDataFormatException(
+//                                "malformed input: partial character at end");
+//                    char2 = (int) bytearr[count-1];
+//                    if ((char2 & 0xC0) != 0x80)
+//                        throw new UTFDataFormatException(
+//                                "malformed input around byte " + count);
+//                    chararr[chararr_count++]=(char)(((c & 0x1F) << 6) |
+//                            (char2 & 0x3F));
+//                    break;
+//                case 14:
+//                    /* 1110 xxxx  10xx xxxx  10xx xxxx */
+//                    count += 3;
+//                    if (count > utflen)
+//                        throw new UTFDataFormatException(
+//                                "malformed input: partial character at end");
+//                    char2 = (int) bytearr[count-2];
+//                    char3 = (int) bytearr[count-1];
+//                    if (((char2 & 0xC0) != 0x80) || ((char3 & 0xC0) != 0x80))
+//                        throw new UTFDataFormatException(
+//                                "malformed input around byte " + (count-1));
+//                    chararr[chararr_count++]=(char)(((c     & 0x0F) << 12) |
+//                            ((char2 & 0x3F) << 6)  |
+//                            ((char3 & 0x3F) << 0));
+//                    break;
+//                default:
+//                    /* 10xx xxxx,  1111 xxxx */
+//                    throw new UTFDataFormatException(
+//                            "malformed input around byte " + count);
+//            }
+//        }
+//        // The number of chars produced may be less than utflen
+//        return new String(chararr, 0, chararr_count);
+//    }
+
+    @Override
+    public void close() throws IOException {
+        try {
+            dis.close();
+        } catch (Exception e) {
+            e.printStackTrace();
+        }
+
+        try {
+            fis.close();
+        } catch (Exception e) {
+            e.printStackTrace();
+        }
+        try {
+            pfd.close();
+        } catch (Exception e) {
+            e.printStackTrace();
+        }
+
+
+    }
+}

epublib/src/main/java/me/ag2s/epublib/zip/CRC32.java

@@ -0,0 +1,134 @@
+/* CRC32.java - Computes CRC32 data checksum of a data stream
+   Copyright (C) 1999. 2000, 2001 Free Software Foundation, Inc.
+
+This file is part of GNU Classpath.
+
+GNU Classpath is free software; you can redistribute it and/or modify
+it under the terms of the GNU General Public License as published by
+the Free Software Foundation; either version 2, or (at your option)
+any later version.
+
+GNU Classpath is distributed in the hope that it will be useful, but
+WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+General Public License for more details.
+
+You should have received a copy of the GNU General Public License
+along with GNU Classpath; see the file COPYING.  If not, write to the
+Free Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
+02111-1307 USA.
+
+Linking this library statically or dynamically with other modules is
+making a combined work based on this library.  Thus, the terms and
+conditions of the GNU General Public License cover the whole
+combination.
+
+As a special exception, the copyright holders of this library give you
+permission to link this library with independent modules to produce an
+executable, regardless of the license terms of these independent
+modules, and to copy and distribute the resulting executable under
+terms of your choice, provided that you also meet, for each linked
+independent module, the terms and conditions of the license of that
+module.  An independent module is a module which is not derived from
+or based on this library.  If you modify this library, you may extend
+this exception to your version of the library, but you are not
+obligated to do so.  If you do not wish to do so, delete this
+exception statement from your version. */
+
+package me.ag2s.epublib.zip;
+
+/*
+ * Written using on-line Java Platform 1.2 API Specification, as well
+ * as "The Java Class Libraries", 2nd edition (Addison-Wesley, 1998).
+ * The actual CRC32 algorithm is taken from RFC 1952.
+ * Status:  Believed complete and correct.
+ */
+
+/**
+ * Computes CRC32 data checksum of a data stream.
+ * The actual CRC32 algorithm is described in RFC 1952
+ * (GZIP file format specification version 4.3).
+ * Can be used to get the CRC32 over a stream if used with checked input/output
+ * streams.
+ *
+ * @author Per Bothner
+ * @date April 1, 1999.
+ * @see InflaterInputStream
+ * @see DeflaterOutputStream
+ */
+public class CRC32 implements Checksum {
+    /**
+     * The crc data checksum so far.
+     */
+    private int crc = 0;
+
+    /**
+     * The fast CRC table. Computed once when the CRC32 class is loaded.
+     */
+    private static final int[] crc_table = make_crc_table();
+
+    /**
+     * Make the table for a fast CRC.
+     */
+    private static int[] make_crc_table() {
+        int[] crc_table = new int[256];
+        for (int n = 0; n < 256; n++) {
+            int c = n;
+            for (int k = 8; --k >= 0; ) {
+                if ((c & 1) != 0)
+                    c = 0xedb88320 ^ (c >>> 1);
+                else
+                    c = c >>> 1;
+            }
+            crc_table[n] = c;
+        }
+        return crc_table;
+    }
+
+    /**
+     * Returns the CRC32 data checksum computed so far.
+     */
+    public long getValue() {
+        return (long) crc & 0xffffffffL;
+    }
+
+    /**
+     * Resets the CRC32 data checksum as if no update was ever called.
+     */
+    public void reset() {
+        crc = 0;
+    }
+
+    /**
+     * Updates the checksum with the int bval.
+     *
+     * @param bval (the byte is taken as the lower 8 bits of bval)
+     */
+
+    public void update(int bval) {
+        int c = ~crc;
+        c = crc_table[(c ^ bval) & 0xff] ^ (c >>> 8);
+        crc = ~c;
+    }
+
+    /**
+     * Adds the byte array to the data checksum.
+     *
+     * @param buf the buffer which contains the data
+     * @param off the offset in the buffer where the data starts
+     * @param len the length of the data
+     */
+    public void update(byte[] buf, int off, int len) {
+        int c = ~crc;
+        while (--len >= 0)
+            c = crc_table[(c ^ buf[off++]) & 0xff] ^ (c >>> 8);
+        crc = ~c;
+    }
+
+    /**
+     * Adds the complete byte array to the data checksum.
+     */
+    public void update(byte[] buf) {
+        update(buf, 0, buf.length);
+    }
+}

epublib/src/main/java/me/ag2s/epublib/zip/CheckedInputStream.java

@@ -0,0 +1,128 @@
+/* CheckedInputStream.java - Compute checksum of data being read
+   Copyright (C) 1999, 2000 Free Software Foundation, Inc.
+
+This file is part of GNU Classpath.
+
+GNU Classpath is free software; you can redistribute it and/or modify
+it under the terms of the GNU General Public License as published by
+the Free Software Foundation; either version 2, or (at your option)
+any later version.
+ 
+GNU Classpath is distributed in the hope that it will be useful, but
+WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+General Public License for more details.
+
+You should have received a copy of the GNU General Public License
+along with GNU Classpath; see the file COPYING.  If not, write to the
+Free Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
+02111-1307 USA.
+
+Linking this library statically or dynamically with other modules is
+making a combined work based on this library.  Thus, the terms and
+conditions of the GNU General Public License cover the whole
+combination.
+
+As a special exception, the copyright holders of this library give you
+permission to link this library with independent modules to produce an
+executable, regardless of the license terms of these independent
+modules, and to copy and distribute the resulting executable under
+terms of your choice, provided that you also meet, for each linked
+independent module, the terms and conditions of the license of that
+module.  An independent module is a module which is not derived from
+or based on this library.  If you modify this library, you may extend
+this exception to your version of the library, but you are not
+obligated to do so.  If you do not wish to do so, delete this
+exception statement from your version. */
+
+package me.ag2s.epublib.zip;
+
+import java.io.FilterInputStream;
+import java.io.IOException;
+import java.io.InputStream;
+
+/* Written using on-line Java Platform 1.2 API Specification
+ * and JCL book.
+ * Believed complete and correct.
+ */
+
+/**
+ * InputStream that computes a checksum of the data being read using a
+ * supplied Checksum object.
+ *
+ * @author Tom Tromey
+ * @date May 17, 1999
+ * @see Checksum
+ */
+public class CheckedInputStream extends FilterInputStream {
+  /**
+   * Creates a new CheckInputStream on top of the supplied OutputStream
+   * using the supplied Checksum.
+   */
+  public CheckedInputStream(InputStream in, Checksum sum) {
+    super(in);
+    this.sum = sum;
+  }
+
+  /**
+   * Returns the Checksum object used. To get the data checksum computed so
+   * far call <code>getChecksum.getValue()</code>.
+   */
+  public Checksum getChecksum() {
+    return sum;
+  }
+
+  /**
+   * Reads one byte, updates the checksum and returns the read byte
+   * (or -1 when the end of file was reached).
+   */
+  public int read() throws IOException {
+    int x = in.read();
+    if (x != -1)
+      sum.update(x);
+    return x;
+  }
+
+  /**
+   * Reads at most len bytes in the supplied buffer and updates the checksum
+   * with it. Returns the number of bytes actually read or -1 when the end
+   * of file was reached.
+   */
+  public int read(byte[] buf, int off, int len) throws IOException {
+    int r = in.read(buf, off, len);
+    if (r != -1)
+      sum.update(buf, off, r);
+    return r;
+  }
+
+  /**
+   * Skips n bytes by reading them in a temporary buffer and updating the
+   * the checksum with that buffer. Returns the actual number of bytes skiped
+   * which can be less then requested when the end of file is reached.
+   */
+  public long skip(long n) throws IOException {
+    if (n == 0)
+      return 0;
+
+    int min = (int) Math.min(n, 1024);
+    byte[] buf = new byte[min];
+
+    long s = 0;
+    while (n > 0) {
+      int r = in.read(buf, 0, min);
+      if (r == -1)
+        break;
+      n -= r;
+      s += r;
+      min = (int) Math.min(n, 1024);
+      sum.update(buf, 0, r);
+    }
+
+    return s;
+  }
+
+  /**
+   * The checksum object.
+   */
+  private final Checksum sum;
+}

epublib/src/main/java/me/ag2s/epublib/zip/CheckedOutputStream.java

@@ -0,0 +1,95 @@
+/* CheckedOutputStream.java - Compute checksum of data being written.
+   Copyright (C) 1999, 2000 Free Software Foundation, Inc.
+
+This file is part of GNU Classpath.
+
+GNU Classpath is free software; you can redistribute it and/or modify
+it under the terms of the GNU General Public License as published by
+the Free Software Foundation; either version 2, or (at your option)
+any later version.
+ 
+GNU Classpath is distributed in the hope that it will be useful, but
+WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+General Public License for more details.
+
+You should have received a copy of the GNU General Public License
+along with GNU Classpath; see the file COPYING.  If not, write to the
+Free Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
+02111-1307 USA.
+
+Linking this library statically or dynamically with other modules is
+making a combined work based on this library.  Thus, the terms and
+conditions of the GNU General Public License cover the whole
+combination.
+
+As a special exception, the copyright holders of this library give you
+permission to link this library with independent modules to produce an
+executable, regardless of the license terms of these independent
+modules, and to copy and distribute the resulting executable under
+terms of your choice, provided that you also meet, for each linked
+independent module, the terms and conditions of the license of that
+module.  An independent module is a module which is not derived from
+or based on this library.  If you modify this library, you may extend
+this exception to your version of the library, but you are not
+obligated to do so.  If you do not wish to do so, delete this
+exception statement from your version. */
+
+package me.ag2s.epublib.zip;
+
+import java.io.FilterOutputStream;
+import java.io.IOException;
+import java.io.OutputStream;
+
+/* Written using on-line Java Platform 1.2 API Specification
+ * and JCL book.
+ * Believed complete and correct.
+ */
+
+/**
+ * OutputStream that computes a checksum of data being written using a
+ * supplied Checksum object.
+ *
+ * @author Tom Tromey
+ * @date May 17, 1999
+ * @see Checksum
+ */
+public class CheckedOutputStream extends FilterOutputStream {
+  /**
+   * Creates a new CheckInputStream on top of the supplied OutputStream
+   * using the supplied Checksum.
+   */
+  public CheckedOutputStream(OutputStream out, Checksum cksum) {
+    super(out);
+    this.sum = cksum;
+  }
+
+  /**
+   * Returns the Checksum object used. To get the data checksum computed so
+   * far call <code>getChecksum.getValue()</code>.
+   */
+  public Checksum getChecksum() {
+    return sum;
+  }
+
+  /**
+   * Writes one byte to the OutputStream and updates the Checksum.
+   */
+  public void write(int bval) throws IOException {
+    out.write(bval);
+    sum.update(bval);
+  }
+
+  /**
+   * Writes the byte array to the OutputStream and updates the Checksum.
+   */
+  public void write(byte[] buf, int off, int len) throws IOException {
+    out.write(buf, off, len);
+    sum.update(buf, off, len);
+  }
+
+  /**
+   * The checksum object.
+   */
+  private Checksum sum;
+}

epublib/src/main/java/me/ag2s/epublib/zip/Checksum.java

@@ -0,0 +1,84 @@
+/* Checksum.java - Interface to compute a data checksum
+   Copyright (C) 1999, 2000, 2001 Free Software Foundation, Inc.
+
+This file is part of GNU Classpath.
+
+GNU Classpath is free software; you can redistribute it and/or modify
+it under the terms of the GNU General Public License as published by
+the Free Software Foundation; either version 2, or (at your option)
+any later version.
+
+GNU Classpath is distributed in the hope that it will be useful, but
+WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+General Public License for more details.
+
+You should have received a copy of the GNU General Public License
+along with GNU Classpath; see the file COPYING.  If not, write to the
+Free Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
+02111-1307 USA.
+
+Linking this library statically or dynamically with other modules is
+making a combined work based on this library.  Thus, the terms and
+conditions of the GNU General Public License cover the whole
+combination.
+
+As a special exception, the copyright holders of this library give you
+permission to link this library with independent modules to produce an
+executable, regardless of the license terms of these independent
+modules, and to copy and distribute the resulting executable under
+terms of your choice, provided that you also meet, for each linked
+independent module, the terms and conditions of the license of that
+module.  An independent module is a module which is not derived from
+or based on this library.  If you modify this library, you may extend
+this exception to your version of the library, but you are not
+obligated to do so.  If you do not wish to do so, delete this
+exception statement from your version. */
+
+package me.ag2s.epublib.zip;
+
+/*
+ * Written using on-line Java Platform 1.2 API Specification, as well
+ * as "The Java Class Libraries", 2nd edition (Addison-Wesley, 1998).
+ * Status:  Believed complete and correct.
+ */
+
+/**
+ * Interface to compute a data checksum used by checked input/output streams.
+ * A data checksum can be updated by one byte or with a byte array. After each
+ * update the value of the current checksum can be returned by calling
+ * <code>getValue</code>. The complete checksum object can also be reset
+ * so it can be used again with new data.
+ *
+ * @author Per Bothner
+ * @author Jochen Hoenicke
+ * @see CheckedInputStream
+ * @see CheckedOutputStream
+ */
+public interface Checksum {
+    /**
+     * Returns the data checksum computed so far.
+     */
+    long getValue();
+
+    /**
+     * Resets the data checksum as if no update was ever called.
+     */
+    void reset();
+
+    /**
+     * Adds one byte to the data checksum.
+     *
+     * @param bval the data value to add. The high byte of the int is ignored.
+     */
+    void update(int bval);
+
+    /**
+     * Adds the byte array to the data checksum.
+     *
+     * @param buf the buffer which contains the data
+     * @param off the offset in the buffer where the data starts
+     * @param len the length of the data
+     */
+    void update(byte[] buf, int off, int len);
+}

epublib/src/main/java/me/ag2s/epublib/zip/DataFormatException.java

@@ -0,0 +1,68 @@
+/* DataformatException.java -- thrown when compressed data is corrupt
+   Copyright (C) 1999, 2000, 2001, 2002 Free Software Foundation, Inc.
+
+This file is part of GNU Classpath.
+
+GNU Classpath is free software; you can redistribute it and/or modify
+it under the terms of the GNU General Public License as published by
+the Free Software Foundation; either version 2, or (at your option)
+any later version.
+
+GNU Classpath is distributed in the hope that it will be useful, but
+WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+General Public License for more details.
+
+You should have received a copy of the GNU General Public License
+along with GNU Classpath; see the file COPYING.  If not, write to the
+Free Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
+02111-1307 USA.
+
+Linking this library statically or dynamically with other modules is
+making a combined work based on this library.  Thus, the terms and
+conditions of the GNU General Public License cover the whole
+combination.
+
+As a special exception, the copyright holders of this library give you
+permission to link this library with independent modules to produce an
+executable, regardless of the license terms of these independent
+modules, and to copy and distribute the resulting executable under
+terms of your choice, provided that you also meet, for each linked
+independent module, the terms and conditions of the license of that
+module.  An independent module is a module which is not derived from
+or based on this library.  If you modify this library, you may extend
+this exception to your version of the library, but you are not
+obligated to do so.  If you do not wish to do so, delete this
+exception statement from your version. */
+
+package me.ag2s.epublib.zip;
+
+/**
+ * Exception thrown when compressed data is corrupt.
+ *
+ * @author Tom Tromey
+ * @author John Leuner
+ * @status updated to 1.4
+ * @since 1.1
+ */
+public class DataFormatException extends Exception {
+    /**
+     * Compatible with JDK 1.1+.
+     */
+    private static final long serialVersionUID = 2219632870893641452L;
+
+    /**
+     * Create an exception without a message.
+     */
+    public DataFormatException() {
+    }
+
+    /**
+     * Create an exception with a message.
+     *
+     * @param msg the message
+     */
+    public DataFormatException(String msg) {
+        super(msg);
+    }
+}

epublib/src/main/java/me/ag2s/epublib/zip/Deflater.java

@@ -0,0 +1,512 @@
+/* Deflater.java - Compress a data stream
+   Copyright (C) 1999, 2000, 2001, 2004 Free Software Foundation, Inc.
+
+This file is part of GNU Classpath.
+
+GNU Classpath is free software; you can redistribute it and/or modify
+it under the terms of the GNU General Public License as published by
+the Free Software Foundation; either version 2, or (at your option)
+any later version.
+
+GNU Classpath is distributed in the hope that it will be useful, but
+WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+General Public License for more details.
+
+You should have received a copy of the GNU General Public License
+along with GNU Classpath; see the file COPYING.  If not, write to the
+Free Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
+02111-1307 USA.
+
+Linking this library statically or dynamically with other modules is
+making a combined work based on this library.  Thus, the terms and
+conditions of the GNU General Public License cover the whole
+combination.
+
+As a special exception, the copyright holders of this library give you
+permission to link this library with independent modules to produce an
+executable, regardless of the license terms of these independent
+modules, and to copy and distribute the resulting executable under
+terms of your choice, provided that you also meet, for each linked
+independent module, the terms and conditions of the license of that
+module.  An independent module is a module which is not derived from
+or based on this library.  If you modify this library, you may extend
+this exception to your version of the library, but you are not
+obligated to do so.  If you do not wish to do so, delete this
+exception statement from your version. */
+
+package me.ag2s.epublib.zip;
+
+/**
+ * This is the Deflater class.  The deflater class compresses input
+ * with the deflate algorithm described in RFC 1951.  It has several
+ * compression levels and three different strategies described below.
+ * <p>
+ * This class is <i>not</i> thread safe.  This is inherent in the API, due
+ * to the split of deflate and setInput.
+ *
+ * @author Jochen Hoenicke
+ * @author Tom Tromey
+ */
+public class Deflater {
+    /**
+     * The best and slowest compression level.  This tries to find very
+     * long and distant string repetitions.
+     */
+    public static final int BEST_COMPRESSION = 9;
+    /**
+     * The worst but fastest compression level.
+     */
+    public static final int BEST_SPEED = 1;
+    /**
+     * The default compression level.
+     */
+    public static final int DEFAULT_COMPRESSION = -1;
+    /**
+     * This level won't compress at all but output uncompressed blocks.
+     */
+    public static final int NO_COMPRESSION = 0;
+
+    /**
+     * The default strategy.
+     */
+    public static final int DEFAULT_STRATEGY = 0;
+    /**
+     * This strategy will only allow longer string repetitions.  It is
+     * useful for random data with a small character set.
+     */
+    public static final int FILTERED = 1;
+
+    /**
+     * This strategy will not look for string repetitions at all.  It
+     * only encodes with Huffman trees (which means, that more common
+     * characters get a smaller encoding.
+     */
+    public static final int HUFFMAN_ONLY = 2;
+
+    /**
+     * The compression method.  This is the only method supported so far.
+     * There is no need to use this constant at all.
+     */
+    public static final int DEFLATED = 8;
+
+    /*
+     * The Deflater can do the following state transitions:
+     *
+     * (1) -> INIT_STATE   ----> INIT_FINISHING_STATE ---.
+     *        /  | (2)      (5)                         |
+     *       /   v          (5)                         |
+     *   (3)| SETDICT_STATE ---> SETDICT_FINISHING_STATE |(3)
+     *       \   | (3)                 |        ,-------'
+     *        |  |                     | (3)   /
+     *        v  v          (5)        v      v
+     * (1) -> BUSY_STATE   ----> FINISHING_STATE
+     *                                | (6)
+     *                                v
+     *                           FINISHED_STATE
+     *    \_____________________________________/
+     *          | (7)
+     *          v
+     *        CLOSED_STATE
+     *
+     * (1) If we should produce a header we start in INIT_STATE, otherwise
+     *     we start in BUSY_STATE.
+     * (2) A dictionary may be set only when we are in INIT_STATE, then
+     *     we change the state as indicated.
+     * (3) Whether a dictionary is set or not, on the first call of deflate
+     *     we change to BUSY_STATE.
+     * (4) -- intentionally left blank -- :)
+     * (5) FINISHING_STATE is entered, when flush() is called to indicate that
+     *     there is no more INPUT.  There are also states indicating, that
+     *     the header wasn't written yet.
+     * (6) FINISHED_STATE is entered, when everything has been flushed to the
+     *     internal pending output buffer.
+     * (7) At any time (7)
+     *
+     */
+
+    private static final int IS_SETDICT = 0x01;
+    private static final int IS_FLUSHING = 0x04;
+    private static final int IS_FINISHING = 0x08;
+
+    private static final int INIT_STATE = 0x00;
+    private static final int SETDICT_STATE = 0x01;
+    private static final int INIT_FINISHING_STATE = 0x08;
+    private static final int SETDICT_FINISHING_STATE = 0x09;
+    private static final int BUSY_STATE = 0x10;
+    private static final int FLUSHING_STATE = 0x14;
+    private static final int FINISHING_STATE = 0x1c;
+    private static final int FINISHED_STATE = 0x1e;
+    private static final int CLOSED_STATE = 0x7f;
+
+    /**
+     * Compression level.
+     */
+    private int level;
+
+    /**
+     * should we include a header.
+     */
+    private boolean noHeader;
+
+    /**
+     * The current state.
+     */
+    private int state;
+
+    /**
+     * The total bytes of output written.
+     */
+    private int totalOut;
+
+    /**
+     * The pending output.
+     */
+    private DeflaterPending pending;
+
+    /**
+     * The deflater engine.
+     */
+    private DeflaterEngine engine;
+
+    /**
+     * Creates a new deflater with default compression level.
+     */
+    public Deflater() {
+        this(DEFAULT_COMPRESSION, false);
+    }
+
+    /**
+     * Creates a new deflater with given compression level.
+     *
+     * @param lvl the compression level, a value between NO_COMPRESSION
+     *            and BEST_COMPRESSION, or DEFAULT_COMPRESSION.
+     * @throws IllegalArgumentException if lvl is out of range.
+     */
+    public Deflater(int lvl) {
+        this(lvl, false);
+    }
+
+    /**
+     * Creates a new deflater with given compression level.
+     *
+     * @param lvl    the compression level, a value between NO_COMPRESSION
+     *               and BEST_COMPRESSION.
+     * @param nowrap true, iff we should suppress the deflate header at the
+     *               beginning and the adler checksum at the end of the output.  This is
+     *               useful for the GZIP format.
+     * @throws IllegalArgumentException if lvl is out of range.
+     */
+    public Deflater(int lvl, boolean nowrap) {
+        if (lvl == DEFAULT_COMPRESSION)
+            lvl = 6;
+        else if (lvl < NO_COMPRESSION || lvl > BEST_COMPRESSION)
+            throw new IllegalArgumentException();
+
+        pending = new DeflaterPending();
+        engine = new DeflaterEngine(pending);
+        this.noHeader = nowrap;
+        setStrategy(DEFAULT_STRATEGY);
+        setLevel(lvl);
+        reset();
+    }
+
+    /**
+     * Resets the deflater.  The deflater acts afterwards as if it was
+     * just created with the same compression level and strategy as it
+     * had before.
+     */
+    public void reset() {
+        state = (noHeader ? BUSY_STATE : INIT_STATE);
+        totalOut = 0;
+        pending.reset();
+        engine.reset();
+    }
+
+    /**
+     * Frees all objects allocated by the compressor.  There's no
+     * reason to call this, since you can just rely on garbage
+     * collection.  Exists only for compatibility against Sun's JDK,
+     * where the compressor allocates native memory.
+     * If you call any method (even reset) afterwards the behaviour is
+     * <i>undefined</i>.
+     *
+     * @deprecated Just clear all references to deflater instead.
+     */
+    public void end() {
+        engine = null;
+        pending = null;
+        state = CLOSED_STATE;
+    }
+
+    /**
+     * Gets the current adler checksum of the data that was processed so
+     * far.
+     */
+    public int getAdler() {
+        return engine.getAdler();
+    }
+
+    /**
+     * Gets the number of input bytes processed so far.
+     */
+    public int getTotalIn() {
+        return engine.getTotalIn();
+    }
+
+    /**
+     * Gets the number of output bytes so far.
+     */
+    public int getTotalOut() {
+        return totalOut;
+    }
+
+    /**
+     * Finalizes this object.
+     */
+    protected void finalize() {
+        /* Exists solely for compatibility.  We don't have any native state. */
+    }
+
+    /**
+     * Flushes the current input block.  Further calls to deflate() will
+     * produce enough output to inflate everything in the current input
+     * block.  This is not part of Sun's JDK so I have made it package
+     * private.  It is used by DeflaterOutputStream to implement
+     * flush().
+     */
+    void flush() {
+        state |= IS_FLUSHING;
+    }
+
+    /**
+     * Finishes the deflater with the current input block.  It is an error
+     * to give more input after this method was called.  This method must
+     * be called to force all bytes to be flushed.
+     */
+    public void finish() {
+        state |= IS_FLUSHING | IS_FINISHING;
+    }
+
+    /**
+     * Returns true iff the stream was finished and no more output bytes
+     * are available.
+     */
+    public boolean finished() {
+        return state == FINISHED_STATE && pending.isFlushed();
+    }
+
+    /**
+     * Returns true, if the input buffer is empty.
+     * You should then call setInput(). <br>
+     *
+     * <em>NOTE</em>: This method can also return true when the stream
+     * was finished.
+     */
+    public boolean needsInput() {
+        return engine.needsInput();
+    }
+
+    /**
+     * Sets the data which should be compressed next.  This should be only
+     * called when needsInput indicates that more input is needed.
+     * If you call setInput when needsInput() returns false, the
+     * previous input that is still pending will be thrown away.
+     * The given byte array should not be changed, before needsInput() returns
+     * true again.
+     * This call is equivalent to <code>setInput(input, 0, input.length)</code>.
+     *
+     * @param input the buffer containing the input data.
+     * @throws IllegalStateException if the buffer was finished() or ended().
+     */
+    public void setInput(byte[] input) {
+        setInput(input, 0, input.length);
+    }
+
+    /**
+     * Sets the data which should be compressed next.  This should be
+     * only called when needsInput indicates that more input is needed.
+     * The given byte array should not be changed, before needsInput() returns
+     * true again.
+     *
+     * @param input the buffer containing the input data.
+     * @param off   the start of the data.
+     * @param len   the length of the data.
+     * @throws IllegalStateException if the buffer was finished() or ended()
+     *                               or if previous input is still pending.
+     */
+    public void setInput(byte[] input, int off, int len) {
+        if ((state & IS_FINISHING) != 0)
+            throw new IllegalStateException("finish()/end() already called");
+        engine.setInput(input, off, len);
+    }
+
+    /**
+     * Sets the compression level.  There is no guarantee of the exact
+     * position of the change, but if you call this when needsInput is
+     * true the change of compression level will occur somewhere near
+     * before the end of the so far given input.
+     *
+     * @param lvl the new compression level.
+     */
+    public void setLevel(int lvl) {
+        if (lvl == DEFAULT_COMPRESSION)
+            lvl = 6;
+        else if (lvl < NO_COMPRESSION || lvl > BEST_COMPRESSION)
+            throw new IllegalArgumentException();
+
+
+        if (level != lvl) {
+            level = lvl;
+            engine.setLevel(lvl);
+        }
+    }
+
+    /**
+     * Sets the compression strategy. Strategy is one of
+     * DEFAULT_STRATEGY, HUFFMAN_ONLY and FILTERED.  For the exact
+     * position where the strategy is changed, the same as for
+     * setLevel() applies.
+     *
+     * @param stgy the new compression strategy.
+     */
+    public void setStrategy(int stgy) {
+        if (stgy != DEFAULT_STRATEGY && stgy != FILTERED
+                && stgy != HUFFMAN_ONLY)
+            throw new IllegalArgumentException();
+        engine.setStrategy(stgy);
+    }
+
+    /**
+     * Deflates the current input block to the given array.  It returns
+     * the number of bytes compressed, or 0 if either
+     * needsInput() or finished() returns true or length is zero.
+     *
+     * @param output the buffer where to write the compressed data.
+     */
+    public int deflate(byte[] output) {
+        return deflate(output, 0, output.length);
+    }
+
+    /**
+     * Deflates the current input block to the given array.  It returns
+     * the number of bytes compressed, or 0 if either
+     * needsInput() or finished() returns true or length is zero.
+     *
+     * @param output the buffer where to write the compressed data.
+     * @param offset the offset into the output array.
+     * @param length the maximum number of bytes that may be written.
+     * @throws IllegalStateException     if end() was called.
+     * @throws IndexOutOfBoundsException if offset and/or length
+     *                                   don't match the array length.
+     */
+    public int deflate(byte[] output, int offset, int length) {
+        int origLength = length;
+
+        if (state == CLOSED_STATE)
+            throw new IllegalStateException("Deflater closed");
+
+        if (state < BUSY_STATE) {
+            /* output header */
+            int header = (DEFLATED +
+                    ((DeflaterConstants.MAX_WBITS - 8) << 4)) << 8;
+            int level_flags = (level - 1) >> 1;
+            if (level_flags < 0 || level_flags > 3)
+                level_flags = 3;
+            header |= level_flags << 6;
+            if ((state & IS_SETDICT) != 0)
+                /* Dictionary was set */
+                header |= DeflaterConstants.PRESET_DICT;
+            header += 31 - (header % 31);
+
+            pending.writeShortMSB(header);
+            if ((state & IS_SETDICT) != 0) {
+                int chksum = engine.getAdler();
+                engine.resetAdler();
+                pending.writeShortMSB(chksum >> 16);
+                pending.writeShortMSB(chksum & 0xffff);
+            }
+
+            state = BUSY_STATE | (state & (IS_FLUSHING | IS_FINISHING));
+        }
+
+        for (; ; ) {
+            int count = pending.flush(output, offset, length);
+            offset += count;
+            totalOut += count;
+            length -= count;
+            if (length == 0 || state == FINISHED_STATE)
+                break;
+
+            if (!engine.deflate((state & IS_FLUSHING) != 0,
+                    (state & IS_FINISHING) != 0)) {
+                if (state == BUSY_STATE)
+                    /* We need more input now */
+                    return origLength - length;
+                else if (state == FLUSHING_STATE) {
+                    if (level != NO_COMPRESSION) {
+                        /* We have to supply some lookahead.  8 bit lookahead
+                         * are needed by the zlib inflater, and we must fill
+                         * the next byte, so that all bits are flushed.
+                         */
+                        int neededbits = 8 + ((-pending.getBitCount()) & 7);
+                        while (neededbits > 0) {
+                            /* write a static tree block consisting solely of
+                             * an EOF:
+                             */
+                            pending.writeBits(2, 10);
+                            neededbits -= 10;
+                        }
+                    }
+                    state = BUSY_STATE;
+                } else if (state == FINISHING_STATE) {
+                    pending.alignToByte();
+                    /* We have completed the stream */
+                    if (!noHeader) {
+                        int adler = engine.getAdler();
+                        pending.writeShortMSB(adler >> 16);
+                        pending.writeShortMSB(adler & 0xffff);
+                    }
+                    state = FINISHED_STATE;
+                }
+            }
+        }
+
+        return origLength - length;
+    }
+
+    /**
+     * Sets the dictionary which should be used in the deflate process.
+     * This call is equivalent to <code>setDictionary(dict, 0,
+     * dict.length)</code>.
+     *
+     * @param dict the dictionary.
+     * @throws IllegalStateException if setInput () or deflate ()
+     *                               were already called or another dictionary was already set.
+     */
+    public void setDictionary(byte[] dict) {
+        setDictionary(dict, 0, dict.length);
+    }
+
+    /**
+     * Sets the dictionary which should be used in the deflate process.
+     * The dictionary should be a byte array containing strings that are
+     * likely to occur in the data which should be compressed.  The
+     * dictionary is not stored in the compressed output, only a
+     * checksum.  To decompress the output you need to supply the same
+     * dictionary again.
+     *
+     * @param dict   the dictionary.
+     * @param offset an offset into the dictionary.
+     * @param length the length of the dictionary.
+     * @throws IllegalStateException if setInput () or deflate () were
+     *                               already called or another dictionary was already set.
+     */
+    public void setDictionary(byte[] dict, int offset, int length) {
+        if (state != INIT_STATE)
+            throw new IllegalStateException();
+
+        state = SETDICT_STATE;
+        engine.setDictionary(dict, offset, length);
+    }
+}

epublib/src/main/java/me/ag2s/epublib/zip/DeflaterConstants.java

@@ -0,0 +1,77 @@
+/* me.ag2s.epublib.zip.DeflaterConstants
+   Copyright (C) 2001 Free Software Foundation, Inc.
+
+This file is part of GNU Classpath.
+
+GNU Classpath is free software; you can redistribute it and/or modify
+it under the terms of the GNU General Public License as published by
+the Free Software Foundation; either version 2, or (at your option)
+any later version.
+
+GNU Classpath is distributed in the hope that it will be useful, but
+WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+General Public License for more details.
+
+You should have received a copy of the GNU General Public License
+along with GNU Classpath; see the file COPYING.  If not, write to the
+Free Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
+02111-1307 USA.
+
+Linking this library statically or dynamically with other modules is
+making a combined work based on this library.  Thus, the terms and
+conditions of the GNU General Public License cover the whole
+combination.
+
+As a special exception, the copyright holders of this library give you
+permission to link this library with independent modules to produce an
+executable, regardless of the license terms of these independent
+modules, and to copy and distribute the resulting executable under
+terms of your choice, provided that you also meet, for each linked
+independent module, the terms and conditions of the license of that
+module.  An independent module is a module which is not derived from
+or based on this library.  If you modify this library, you may extend
+this exception to your version of the library, but you are not
+obligated to do so.  If you do not wish to do so, delete this
+exception statement from your version. */
+
+package me.ag2s.epublib.zip;
+
+interface DeflaterConstants {
+    final static boolean DEBUGGING = false;
+
+    final static int STORED_BLOCK = 0;
+    final static int STATIC_TREES = 1;
+    final static int DYN_TREES = 2;
+    final static int PRESET_DICT = 0x20;
+
+    final static int DEFAULT_MEM_LEVEL = 8;
+
+    final static int MAX_MATCH = 258;
+    final static int MIN_MATCH = 3;
+
+    final static int MAX_WBITS = 15;
+    final static int WSIZE = 1 << MAX_WBITS;
+    final static int WMASK = WSIZE - 1;
+
+    final static int HASH_BITS = DEFAULT_MEM_LEVEL + 7;
+    final static int HASH_SIZE = 1 << HASH_BITS;
+    final static int HASH_MASK = HASH_SIZE - 1;
+    final static int HASH_SHIFT = (HASH_BITS + MIN_MATCH - 1) / MIN_MATCH;
+
+    final static int MIN_LOOKAHEAD = MAX_MATCH + MIN_MATCH + 1;
+    final static int MAX_DIST = WSIZE - MIN_LOOKAHEAD;
+
+    final static int PENDING_BUF_SIZE = 1 << (DEFAULT_MEM_LEVEL + 8);
+    final static int MAX_BLOCK_SIZE = Math.min(65535, PENDING_BUF_SIZE - 5);
+
+    final static int DEFLATE_STORED = 0;
+    final static int DEFLATE_FAST = 1;
+    final static int DEFLATE_SLOW = 2;
+
+    final static int GOOD_LENGTH[] = {0, 4, 4, 4, 4, 8, 8, 8, 32, 32};
+    final static int MAX_LAZY[] = {0, 4, 5, 6, 4, 16, 16, 32, 128, 258};
+    final static int NICE_LENGTH[] = {0, 8, 16, 32, 16, 32, 128, 128, 258, 258};
+    final static int MAX_CHAIN[] = {0, 4, 8, 32, 16, 32, 128, 256, 1024, 4096};
+    final static int COMPR_FUNC[] = {0, 1, 1, 1, 1, 2, 2, 2, 2, 2};
+}

epublib/src/main/java/me/ag2s/epublib/zip/DeflaterEngine.java

@@ -0,0 +1,653 @@
+/* me.ag2s.epublib.zip.DeflaterEngine
+   Copyright (C) 2001 Free Software Foundation, Inc.
+
+This file is part of GNU Classpath.
+
+GNU Classpath is free software; you can redistribute it and/or modify
+it under the terms of the GNU General Public License as published by
+the Free Software Foundation; either version 2, or (at your option)
+any later version.
+
+GNU Classpath is distributed in the hope that it will be useful, but
+WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+General Public License for more details.
+
+You should have received a copy of the GNU General Public License
+along with GNU Classpath; see the file COPYING.  If not, write to the
+Free Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
+02111-1307 USA.
+
+Linking this library statically or dynamically with other modules is
+making a combined work based on this library.  Thus, the terms and
+conditions of the GNU General Public License cover the whole
+combination.
+
+As a special exception, the copyright holders of this library give you
+permission to link this library with independent modules to produce an
+executable, regardless of the license terms of these independent
+modules, and to copy and distribute the resulting executable under
+terms of your choice, provided that you also meet, for each linked
+independent module, the terms and conditions of the license of that
+module.  An independent module is a module which is not derived from
+or based on this library.  If you modify this library, you may extend
+this exception to your version of the library, but you are not
+obligated to do so.  If you do not wish to do so, delete this
+exception statement from your version. */
+
+package me.ag2s.epublib.zip;
+
+class DeflaterEngine implements DeflaterConstants {
+    private final static int TOO_FAR = 4096;
+
+    private int ins_h;
+
+    /**
+     * Hashtable, hashing three characters to an index for window, so
+     * that window[index]..window[index+2] have this hash code.
+     * Note that the array should really be unsigned short, so you need
+     * to and the values with 0xffff.
+     */
+    private short[] head;
+
+    /**
+     * prev[index & WMASK] points to the previous index that has the
+     * same hash code as the string starting at index.  This way
+     * entries with the same hash code are in a linked list.
+     * Note that the array should really be unsigned short, so you need
+     * to and the values with 0xffff.
+     */
+    private short[] prev;
+
+    private int matchStart, matchLen;
+    private boolean prevAvailable;
+    private int blockStart;
+
+    /**
+     * strstart points to the current character in window.
+     */
+    private int strstart;
+
+    /**
+     * lookahead is the number of characters starting at strstart in
+     * window that are valid.
+     * So window[strstart] until window[strstart+lookahead-1] are valid
+     * characters.
+     */
+    private int lookahead;
+
+    /**
+     * This array contains the part of the uncompressed stream that
+     * is of relevance.  The current character is indexed by strstart.
+     */
+    private byte[] window;
+
+    private int strategy, max_chain, max_lazy, niceLength, goodLength;
+
+    /**
+     * The current compression function.
+     */
+    private int comprFunc;
+
+    /**
+     * The input data for compression.
+     */
+    private byte[] inputBuf;
+
+    /**
+     * The total bytes of input read.
+     */
+    private int totalIn;
+
+    /**
+     * The offset into inputBuf, where input data starts.
+     */
+    private int inputOff;
+
+    /**
+     * The end offset of the input data.
+     */
+    private int inputEnd;
+
+    private DeflaterPending pending;
+    private DeflaterHuffman huffman;
+
+    /**
+     * The adler checksum
+     */
+    private Adler32 adler;
+
+    /* DEFLATE ALGORITHM:
+     *
+     * The uncompressed stream is inserted into the window array.  When
+     * the window array is full the first half is thrown away and the
+     * second half is copied to the beginning.
+     *
+     * The head array is a hash table.  Three characters build a hash value
+     * and they the value points to the corresponding index in window of
+     * the last string with this hash.  The prev array implements a
+     * linked list of matches with the same hash: prev[index & WMASK] points
+     * to the previous index with the same hash.
+     *
+     *
+     */
+
+
+    DeflaterEngine(DeflaterPending pending) {
+        this.pending = pending;
+        huffman = new DeflaterHuffman(pending);
+        adler = new Adler32();
+
+        window = new byte[2 * WSIZE];
+        head = new short[HASH_SIZE];
+        prev = new short[WSIZE];
+
+        /* We start at index 1, to avoid a implementation deficiency, that
+         * we cannot build a repeat pattern at index 0.
+         */
+        blockStart = strstart = 1;
+    }
+
+    public void reset() {
+        huffman.reset();
+        adler.reset();
+        blockStart = strstart = 1;
+        lookahead = 0;
+        totalIn = 0;
+        prevAvailable = false;
+        matchLen = MIN_MATCH - 1;
+        for (int i = 0; i < HASH_SIZE; i++)
+            head[i] = 0;
+        for (int i = 0; i < WSIZE; i++)
+            prev[i] = 0;
+    }
+
+    public final void resetAdler() {
+        adler.reset();
+    }
+
+    public final int getAdler() {
+        int chksum = (int) adler.getValue();
+        return chksum;
+    }
+
+    public final int getTotalIn() {
+        return totalIn;
+    }
+
+    public final void setStrategy(int strat) {
+        strategy = strat;
+    }
+
+    public void setLevel(int lvl) {
+        goodLength = DeflaterConstants.GOOD_LENGTH[lvl];
+        max_lazy = DeflaterConstants.MAX_LAZY[lvl];
+        niceLength = DeflaterConstants.NICE_LENGTH[lvl];
+        max_chain = DeflaterConstants.MAX_CHAIN[lvl];
+
+        if (DeflaterConstants.COMPR_FUNC[lvl] != comprFunc) {
+            if (DeflaterConstants.DEBUGGING)
+                System.err.println("Change from " + comprFunc + " to "
+                        + DeflaterConstants.COMPR_FUNC[lvl]);
+            switch (comprFunc) {
+                case DEFLATE_STORED:
+                    if (strstart > blockStart) {
+                        huffman.flushStoredBlock(window, blockStart,
+                                strstart - blockStart, false);
+                        blockStart = strstart;
+                    }
+                    updateHash();
+                    break;
+                case DEFLATE_FAST:
+                    if (strstart > blockStart) {
+                        huffman.flushBlock(window, blockStart, strstart - blockStart,
+                                false);
+                        blockStart = strstart;
+                    }
+                    break;
+                case DEFLATE_SLOW:
+                    if (prevAvailable)
+                        huffman.tallyLit(window[strstart - 1] & 0xff);
+                    if (strstart > blockStart) {
+                        huffman.flushBlock(window, blockStart, strstart - blockStart,
+                                false);
+                        blockStart = strstart;
+                    }
+                    prevAvailable = false;
+                    matchLen = MIN_MATCH - 1;
+                    break;
+            }
+            comprFunc = COMPR_FUNC[lvl];
+        }
+    }
+
+    private final void updateHash() {
+        if (DEBUGGING)
+            System.err.println("updateHash: " + strstart);
+        ins_h = (window[strstart] << HASH_SHIFT) ^ window[strstart + 1];
+    }
+
+    /**
+     * Inserts the current string in the head hash and returns the previous
+     * value for this hash.
+     */
+    private final int insertString() {
+        short match;
+        int hash = ((ins_h << HASH_SHIFT) ^ window[strstart + (MIN_MATCH - 1)])
+                & HASH_MASK;
+
+        if (DEBUGGING) {
+            if (hash != (((window[strstart] << (2 * HASH_SHIFT))
+                    ^ (window[strstart + 1] << HASH_SHIFT)
+                    ^ (window[strstart + 2])) & HASH_MASK))
+                throw new InternalError("hash inconsistent: " + hash + "/"
+                        + window[strstart] + ","
+                        + window[strstart + 1] + ","
+                        + window[strstart + 2] + "," + HASH_SHIFT);
+        }
+
+        prev[strstart & WMASK] = match = head[hash];
+        head[hash] = (short) strstart;
+        ins_h = hash;
+        return match & 0xffff;
+    }
+
+    private void slideWindow() {
+        System.arraycopy(window, WSIZE, window, 0, WSIZE);
+        matchStart -= WSIZE;
+        strstart -= WSIZE;
+        blockStart -= WSIZE;
+
+        /* Slide the hash table (could be avoided with 32 bit values
+         * at the expense of memory usage).
+         */
+        for (int i = 0; i < HASH_SIZE; i++) {
+            int m = head[i] & 0xffff;
+            head[i] = m >= WSIZE ? (short) (m - WSIZE) : 0;
+        }
+
+        /* Slide the prev table.
+         */
+        for (int i = 0; i < WSIZE; i++) {
+            int m = prev[i] & 0xffff;
+            prev[i] = m >= WSIZE ? (short) (m - WSIZE) : 0;
+        }
+    }
+
+    /**
+     * Fill the window when the lookahead becomes insufficient.
+     * Updates strstart and lookahead.
+     * <p>
+     * OUT assertions: strstart + lookahead <= 2*WSIZE
+     * lookahead >= MIN_LOOKAHEAD or inputOff == inputEnd
+     */
+    private void fillWindow() {
+        /* If the window is almost full and there is insufficient lookahead,
+         * move the upper half to the lower one to make room in the upper half.
+         */
+        if (strstart >= WSIZE + MAX_DIST)
+            slideWindow();
+
+        /* If there is not enough lookahead, but still some input left,
+         * read in the input
+         */
+        while (lookahead < DeflaterConstants.MIN_LOOKAHEAD && inputOff < inputEnd) {
+            int more = 2 * WSIZE - lookahead - strstart;
+
+            if (more > inputEnd - inputOff)
+                more = inputEnd - inputOff;
+
+            System.arraycopy(inputBuf, inputOff,
+                    window, strstart + lookahead, more);
+            adler.update(inputBuf, inputOff, more);
+            inputOff += more;
+            totalIn += more;
+            lookahead += more;
+        }
+
+        if (lookahead >= MIN_MATCH)
+            updateHash();
+    }
+
+    /**
+     * Find the best (longest) string in the window matching the
+     * string starting at strstart.
+     * <p>
+     * Preconditions:
+     * strstart + MAX_MATCH <= window.length.
+     *
+     * @param curMatch
+     */
+    private boolean findLongestMatch(int curMatch) {
+        int chainLength = this.max_chain;
+        int niceLength = this.niceLength;
+        short[] prev = this.prev;
+        int scan = this.strstart;
+        int match;
+        int best_end = this.strstart + matchLen;
+        int best_len = Math.max(matchLen, MIN_MATCH - 1);
+
+        int limit = Math.max(strstart - MAX_DIST, 0);
+
+        int strend = scan + MAX_MATCH - 1;
+        byte scan_end1 = window[best_end - 1];
+        byte scan_end = window[best_end];
+
+        /* Do not waste too much time if we already have a good match: */
+        if (best_len >= this.goodLength)
+            chainLength >>= 2;
+
+        /* Do not look for matches beyond the end of the input. This is necessary
+         * to make deflate deterministic.
+         */
+        if (niceLength > lookahead)
+            niceLength = lookahead;
+
+        if (DeflaterConstants.DEBUGGING
+                && strstart > 2 * WSIZE - MIN_LOOKAHEAD)
+            throw new InternalError("need lookahead");
+
+        do {
+            if (DeflaterConstants.DEBUGGING && curMatch >= strstart)
+                throw new InternalError("future match");
+            if (window[curMatch + best_len] != scan_end
+                    || window[curMatch + best_len - 1] != scan_end1
+                    || window[curMatch] != window[scan]
+                    || window[curMatch + 1] != window[scan + 1])
+                continue;
+
+            match = curMatch + 2;
+            scan += 2;
+
+            /* We check for insufficient lookahead only every 8th comparison;
+             * the 256th check will be made at strstart+258.
+             */
+            while (window[++scan] == window[++match]
+                    && window[++scan] == window[++match]
+                    && window[++scan] == window[++match]
+                    && window[++scan] == window[++match]
+                    && window[++scan] == window[++match]
+                    && window[++scan] == window[++match]
+                    && window[++scan] == window[++match]
+                    && window[++scan] == window[++match]
+                    && scan < strend) ;
+
+            if (scan > best_end) {
+//  	if (DeflaterConstants.DEBUGGING && ins_h == 0)
+//  	  System.err.println("Found match: "+curMatch+"-"+(scan-strstart));
+                matchStart = curMatch;
+                best_end = scan;
+                best_len = scan - strstart;
+                if (best_len >= niceLength)
+                    break;
+
+                scan_end1 = window[best_end - 1];
+                scan_end = window[best_end];
+            }
+            scan = strstart;
+        } while ((curMatch = (prev[curMatch & WMASK] & 0xffff)) > limit
+                && --chainLength != 0);
+
+        matchLen = Math.min(best_len, lookahead);
+        return matchLen >= MIN_MATCH;
+    }
+
+    void setDictionary(byte[] buffer, int offset, int length) {
+        if (DeflaterConstants.DEBUGGING && strstart != 1)
+            throw new IllegalStateException("strstart not 1");
+        adler.update(buffer, offset, length);
+        if (length < MIN_MATCH)
+            return;
+        if (length > MAX_DIST) {
+            offset += length - MAX_DIST;
+            length = MAX_DIST;
+        }
+
+        System.arraycopy(buffer, offset, window, strstart, length);
+
+        updateHash();
+        length--;
+        while (--length > 0) {
+            insertString();
+            strstart++;
+        }
+        strstart += 2;
+        blockStart = strstart;
+    }
+
+    private boolean deflateStored(boolean flush, boolean finish) {
+        if (!flush && lookahead == 0)
+            return false;
+
+        strstart += lookahead;
+        lookahead = 0;
+
+        int storedLen = strstart - blockStart;
+
+        if ((storedLen >= DeflaterConstants.MAX_BLOCK_SIZE)
+                /* Block is full */
+                || (blockStart < WSIZE && storedLen >= MAX_DIST)
+                /* Block may move out of window */
+                || flush) {
+            boolean lastBlock = finish;
+            if (storedLen > DeflaterConstants.MAX_BLOCK_SIZE) {
+                storedLen = DeflaterConstants.MAX_BLOCK_SIZE;
+                lastBlock = false;
+            }
+
+            if (DeflaterConstants.DEBUGGING)
+                System.err.println("storedBlock[" + storedLen + "," + lastBlock + "]");
+
+            huffman.flushStoredBlock(window, blockStart, storedLen, lastBlock);
+            blockStart += storedLen;
+            return !lastBlock;
+        }
+        return true;
+    }
+
+    private boolean deflateFast(boolean flush, boolean finish) {
+        if (lookahead < MIN_LOOKAHEAD && !flush)
+            return false;
+
+        while (lookahead >= MIN_LOOKAHEAD || flush) {
+            if (lookahead == 0) {
+                /* We are flushing everything */
+                huffman.flushBlock(window, blockStart, strstart - blockStart,
+                        finish);
+                blockStart = strstart;
+                return false;
+            }
+
+            if (strstart > 2 * WSIZE - MIN_LOOKAHEAD) {
+                /* slide window, as findLongestMatch need this.
+                 * This should only happen when flushing and the window
+                 * is almost full.
+                 */
+                slideWindow();
+            }
+
+            int hashHead;
+            if (lookahead >= MIN_MATCH
+                    && (hashHead = insertString()) != 0
+                    && strategy != Deflater.HUFFMAN_ONLY
+                    && strstart - hashHead <= MAX_DIST
+                    && findLongestMatch(hashHead)) {
+                /* longestMatch sets matchStart and matchLen */
+                if (DeflaterConstants.DEBUGGING) {
+                    for (int i = 0; i < matchLen; i++) {
+                        if (window[strstart + i] != window[matchStart + i])
+                            throw new InternalError();
+                    }
+                }
+                huffman.tallyDist(strstart - matchStart, matchLen);
+
+                lookahead -= matchLen;
+                if (matchLen <= max_lazy && lookahead >= MIN_MATCH) {
+                    while (--matchLen > 0) {
+                        strstart++;
+                        insertString();
+                    }
+                    strstart++;
+                } else {
+                    strstart += matchLen;
+                    if (lookahead >= MIN_MATCH - 1)
+                        updateHash();
+                }
+                matchLen = MIN_MATCH - 1;
+                continue;
+            } else {
+                /* No match found */
+                huffman.tallyLit(window[strstart] & 0xff);
+                strstart++;
+                lookahead--;
+            }
+
+            if (huffman.isFull()) {
+                boolean lastBlock = finish && lookahead == 0;
+                huffman.flushBlock(window, blockStart, strstart - blockStart,
+                        lastBlock);
+                blockStart = strstart;
+                return !lastBlock;
+            }
+        }
+        return true;
+    }
+
+    private boolean deflateSlow(boolean flush, boolean finish) {
+        if (lookahead < MIN_LOOKAHEAD && !flush)
+            return false;
+
+        while (lookahead >= MIN_LOOKAHEAD || flush) {
+            if (lookahead == 0) {
+                if (prevAvailable)
+                    huffman.tallyLit(window[strstart - 1] & 0xff);
+                prevAvailable = false;
+
+                /* We are flushing everything */
+                if (DeflaterConstants.DEBUGGING && !flush)
+                    throw new InternalError("Not flushing, but no lookahead");
+                huffman.flushBlock(window, blockStart, strstart - blockStart,
+                        finish);
+                blockStart = strstart;
+                return false;
+            }
+
+            if (strstart >= 2 * WSIZE - MIN_LOOKAHEAD) {
+                /* slide window, as findLongestMatch need this.
+                 * This should only happen when flushing and the window
+                 * is almost full.
+                 */
+                slideWindow();
+            }
+
+            int prevMatch = matchStart;
+            int prevLen = matchLen;
+            if (lookahead >= MIN_MATCH) {
+                int hashHead = insertString();
+                if (strategy != Deflater.HUFFMAN_ONLY
+                        && hashHead != 0 && strstart - hashHead <= MAX_DIST
+                        && findLongestMatch(hashHead)) {
+                    /* longestMatch sets matchStart and matchLen */
+
+                    /* Discard match if too small and too far away */
+                    if (matchLen <= 5
+                            && (strategy == Deflater.FILTERED
+                            || (matchLen == MIN_MATCH
+                            && strstart - matchStart > TOO_FAR))) {
+                        matchLen = MIN_MATCH - 1;
+                    }
+                }
+            }
+
+            /* previous match was better */
+            if (prevLen >= MIN_MATCH && matchLen <= prevLen) {
+                if (DeflaterConstants.DEBUGGING) {
+                    for (int i = 0; i < matchLen; i++) {
+                        if (window[strstart - 1 + i] != window[prevMatch + i])
+                            throw new InternalError();
+                    }
+                }
+                huffman.tallyDist(strstart - 1 - prevMatch, prevLen);
+                prevLen -= 2;
+                do {
+                    strstart++;
+                    lookahead--;
+                    if (lookahead >= MIN_MATCH)
+                        insertString();
+                }
+                while (--prevLen > 0);
+                strstart++;
+                lookahead--;
+                prevAvailable = false;
+                matchLen = MIN_MATCH - 1;
+            } else {
+                if (prevAvailable)
+                    huffman.tallyLit(window[strstart - 1] & 0xff);
+                prevAvailable = true;
+                strstart++;
+                lookahead--;
+            }
+
+            if (huffman.isFull()) {
+                int len = strstart - blockStart;
+                if (prevAvailable)
+                    len--;
+                boolean lastBlock = (finish && lookahead == 0 && !prevAvailable);
+                huffman.flushBlock(window, blockStart, len, lastBlock);
+                blockStart += len;
+                return !lastBlock;
+            }
+        }
+        return true;
+    }
+
+    public boolean deflate(boolean flush, boolean finish) {
+        boolean progress;
+        do {
+            fillWindow();
+            boolean canFlush = flush && inputOff == inputEnd;
+            if (DeflaterConstants.DEBUGGING)
+                System.err.println("window: [" + blockStart + "," + strstart + ","
+                        + lookahead + "], " + comprFunc + "," + canFlush);
+            switch (comprFunc) {
+                case DEFLATE_STORED:
+                    progress = deflateStored(canFlush, finish);
+                    break;
+                case DEFLATE_FAST:
+                    progress = deflateFast(canFlush, finish);
+                    break;
+                case DEFLATE_SLOW:
+                    progress = deflateSlow(canFlush, finish);
+                    break;
+                default:
+                    throw new InternalError();
+            }
+        }
+        while (pending.isFlushed()  /* repeat while we have no pending output */
+                && progress);        /* and progress was made */
+
+        return progress;
+    }
+
+    public void setInput(byte[] buf, int off, int len) {
+        if (inputOff < inputEnd)
+            throw new IllegalStateException
+                    ("Old input was not completely processed");
+
+        int end = off + len;
+
+        /* We want to throw an ArrayIndexOutOfBoundsException early.  The
+         * check is very tricky: it also handles integer wrap around.
+         */
+        if (0 > off || off > end || end > buf.length)
+            throw new ArrayIndexOutOfBoundsException();
+
+        inputBuf = buf;
+        inputOff = off;
+        inputEnd = end;
+    }
+
+    public final boolean needsInput() {
+        return inputEnd == inputOff;
+    }
+}

epublib/src/main/java/me/ag2s/epublib/zip/DeflaterHuffman.java

@@ -0,0 +1,704 @@
+/* me.ag2s.epublib.zip.DeflaterHuffman
+   Copyright (C) 2001 Free Software Foundation, Inc.
+
+This file is part of GNU Classpath.
+
+GNU Classpath is free software; you can redistribute it and/or modify
+it under the terms of the GNU General Public License as published by
+the Free Software Foundation; either version 2, or (at your option)
+any later version.
+
+GNU Classpath is distributed in the hope that it will be useful, but
+WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+General Public License for more details.
+
+You should have received a copy of the GNU General Public License
+along with GNU Classpath; see the file COPYING.  If not, write to the
+Free Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
+02111-1307 USA.
+
+Linking this library statically or dynamically with other modules is
+making a combined work based on this library.  Thus, the terms and
+conditions of the GNU General Public License cover the whole
+combination.
+
+As a special exception, the copyright holders of this library give you
+permission to link this library with independent modules to produce an
+executable, regardless of the license terms of these independent
+modules, and to copy and distribute the resulting executable under
+terms of your choice, provided that you also meet, for each linked
+independent module, the terms and conditions of the license of that
+module.  An independent module is a module which is not derived from
+or based on this library.  If you modify this library, you may extend
+this exception to your version of the library, but you are not
+obligated to do so.  If you do not wish to do so, delete this
+exception statement from your version. */
+
+package me.ag2s.epublib.zip;
+
+/**
+ * This is the DeflaterHuffman class.
+ * <p>
+ * This class is <i>not</i> thread safe.  This is inherent in the API, due
+ * to the split of deflate and setInput.
+ *
+ * @author Jochen Hoenicke
+ * @date Jan 6, 2000
+ */
+class DeflaterHuffman {
+    private static final int BUFSIZE = 1 << (DeflaterConstants.DEFAULT_MEM_LEVEL + 6);
+    private static final int LITERAL_NUM = 286;
+    private static final int DIST_NUM = 30;
+    private static final int BITLEN_NUM = 19;
+    private static final int REP_3_6 = 16;
+    private static final int REP_3_10 = 17;
+    private static final int REP_11_138 = 18;
+    private static final int EOF_SYMBOL = 256;
+    private static final int[] BL_ORDER =
+            {16, 17, 18, 0, 8, 7, 9, 6, 10, 5, 11, 4, 12, 3, 13, 2, 14, 1, 15};
+
+    private final static String bit4Reverse =
+            "\000\010\004\014\002\012\006\016\001\011\005\015\003\013\007\017";
+
+    class Tree {
+        short[] freqs;
+        short[] codes;
+        byte[] length;
+        int[] bl_counts;
+        int minNumCodes, numCodes;
+        int maxLength;
+
+        Tree(int elems, int minCodes, int maxLength) {
+            this.minNumCodes = minCodes;
+            this.maxLength = maxLength;
+            freqs = new short[elems];
+            bl_counts = new int[maxLength];
+        }
+
+        void reset() {
+            for (int i = 0; i < freqs.length; i++)
+                freqs[i] = 0;
+            codes = null;
+            length = null;
+        }
+
+        final void writeSymbol(int code) {
+            if (DeflaterConstants.DEBUGGING) {
+                freqs[code]--;
+//  	  System.err.print("writeSymbol("+freqs.length+","+code+"): ");
+            }
+            pending.writeBits(codes[code] & 0xffff, length[code]);
+        }
+
+        final void checkEmpty() {
+            boolean empty = true;
+            for (int i = 0; i < freqs.length; i++)
+                if (freqs[i] != 0) {
+                    System.err.println("freqs[" + i + "] == " + freqs[i]);
+                    empty = false;
+                }
+            if (!empty)
+                throw new InternalError();
+            System.err.println("checkEmpty suceeded!");
+        }
+
+        void setStaticCodes(short[] stCodes, byte[] stLength) {
+            codes = stCodes;
+            length = stLength;
+        }
+
+        public void buildCodes() {
+            int[] nextCode = new int[maxLength];
+            int code = 0;
+            codes = new short[freqs.length];
+
+            if (DeflaterConstants.DEBUGGING)
+                System.err.println("buildCodes: " + freqs.length);
+            for (int bits = 0; bits < maxLength; bits++) {
+                nextCode[bits] = code;
+                code += bl_counts[bits] << (15 - bits);
+                if (DeflaterConstants.DEBUGGING)
+                    System.err.println("bits: " + (bits + 1) + " count: " + bl_counts[bits]
+                            + " nextCode: " + Integer.toHexString(code));
+            }
+            if (DeflaterConstants.DEBUGGING && code != 65536)
+                throw new RuntimeException("Inconsistent bl_counts!");
+
+            for (int i = 0; i < numCodes; i++) {
+                int bits = length[i];
+                if (bits > 0) {
+                    if (DeflaterConstants.DEBUGGING)
+                        System.err.println("codes[" + i + "] = rev("
+                                + Integer.toHexString(nextCode[bits - 1]) + "),"
+                                + bits);
+                    codes[i] = bitReverse(nextCode[bits - 1]);
+                    nextCode[bits - 1] += 1 << (16 - bits);
+                }
+            }
+        }
+
+        private void buildLength(int childs[]) {
+            this.length = new byte[freqs.length];
+            int numNodes = childs.length / 2;
+            int numLeafs = (numNodes + 1) / 2;
+            int overflow = 0;
+
+            for (int i = 0; i < maxLength; i++)
+                bl_counts[i] = 0;
+
+            /* First calculate optimal bit lengths */
+            int lengths[] = new int[numNodes];
+            lengths[numNodes - 1] = 0;
+            for (int i = numNodes - 1; i >= 0; i--) {
+                if (childs[2 * i + 1] != -1) {
+                    int bitLength = lengths[i] + 1;
+                    if (bitLength > maxLength) {
+                        bitLength = maxLength;
+                        overflow++;
+                    }
+                    lengths[childs[2 * i]] = lengths[childs[2 * i + 1]] = bitLength;
+                } else {
+                    /* A leaf node */
+                    int bitLength = lengths[i];
+                    bl_counts[bitLength - 1]++;
+                    this.length[childs[2 * i]] = (byte) lengths[i];
+                }
+            }
+
+            if (DeflaterConstants.DEBUGGING) {
+                System.err.println("Tree " + freqs.length + " lengths:");
+                for (int i = 0; i < numLeafs; i++)
+                    System.err.println("Node " + childs[2 * i] + " freq: " + freqs[childs[2 * i]]
+                            + " len: " + length[childs[2 * i]]);
+            }
+
+            if (overflow == 0)
+                return;
+
+            int incrBitLen = maxLength - 1;
+            do {
+                /* Find the first bit length which could increase: */
+                while (bl_counts[--incrBitLen] == 0)
+                    ;
+
+                /* Move this node one down and remove a corresponding
+                 * amount of overflow nodes.
+                 */
+                do {
+                    bl_counts[incrBitLen]--;
+                    bl_counts[++incrBitLen]++;
+                    overflow -= 1 << (maxLength - 1 - incrBitLen);
+                }
+                while (overflow > 0 && incrBitLen < maxLength - 1);
+            }
+            while (overflow > 0);
+
+            /* We may have overshot above.  Move some nodes from maxLength to
+             * maxLength-1 in that case.
+             */
+            bl_counts[maxLength - 1] += overflow;
+            bl_counts[maxLength - 2] -= overflow;
+
+            /* Now recompute all bit lengths, scanning in increasing
+             * frequency.  It is simpler to reconstruct all lengths instead of
+             * fixing only the wrong ones. This idea is taken from 'ar'
+             * written by Haruhiko Okumura.
+             *
+             * The nodes were inserted with decreasing frequency into the childs
+             * array.
+             */
+            int nodePtr = 2 * numLeafs;
+            for (int bits = maxLength; bits != 0; bits--) {
+                int n = bl_counts[bits - 1];
+                while (n > 0) {
+                    int childPtr = 2 * childs[nodePtr++];
+                    if (childs[childPtr + 1] == -1) {
+                        /* We found another leaf */
+                        length[childs[childPtr]] = (byte) bits;
+                        n--;
+                    }
+                }
+            }
+            if (DeflaterConstants.DEBUGGING) {
+                System.err.println("*** After overflow elimination. ***");
+                for (int i = 0; i < numLeafs; i++)
+                    System.err.println("Node " + childs[2 * i] + " freq: " + freqs[childs[2 * i]]
+                            + " len: " + length[childs[2 * i]]);
+            }
+        }
+
+        void buildTree() {
+            int numSymbols = freqs.length;
+
+            /* heap is a priority queue, sorted by frequency, least frequent
+             * nodes first.  The heap is a binary tree, with the property, that
+             * the parent node is smaller than both child nodes.  This assures
+             * that the smallest node is the first parent.
+             *
+             * The binary tree is encoded in an array:  0 is root node and
+             * the nodes 2*n+1, 2*n+2 are the child nodes of node n.
+             */
+            int[] heap = new int[numSymbols];
+            int heapLen = 0;
+            int maxCode = 0;
+            for (int n = 0; n < numSymbols; n++) {
+                int freq = freqs[n];
+                if (freq != 0) {
+                    /* Insert n into heap */
+                    int pos = heapLen++;
+                    int ppos;
+                    while (pos > 0 &&
+                            freqs[heap[ppos = (pos - 1) / 2]] > freq) {
+                        heap[pos] = heap[ppos];
+                        pos = ppos;
+                    }
+                    heap[pos] = n;
+                    maxCode = n;
+                }
+            }
+
+            /* We could encode a single literal with 0 bits but then we
+             * don't see the literals.  Therefore we force at least two
+             * literals to avoid this case.  We don't care about order in
+             * this case, both literals get a 1 bit code.
+             */
+            while (heapLen < 2) {
+                int node = maxCode < 2 ? ++maxCode : 0;
+                heap[heapLen++] = node;
+            }
+
+            numCodes = Math.max(maxCode + 1, minNumCodes);
+
+            int numLeafs = heapLen;
+            int[] childs = new int[4 * heapLen - 2];
+            int[] values = new int[2 * heapLen - 1];
+            int numNodes = numLeafs;
+            for (int i = 0; i < heapLen; i++) {
+                int node = heap[i];
+                childs[2 * i] = node;
+                childs[2 * i + 1] = -1;
+                values[i] = freqs[node] << 8;
+                heap[i] = i;
+            }
+
+            /* Construct the Huffman tree by repeatedly combining the least two
+             * frequent nodes.
+             */
+            do {
+                int first = heap[0];
+                int last = heap[--heapLen];
+
+                /* Propagate the hole to the leafs of the heap */
+                int ppos = 0;
+                int path = 1;
+                while (path < heapLen) {
+                    if (path + 1 < heapLen
+                            && values[heap[path]] > values[heap[path + 1]])
+                        path++;
+
+                    heap[ppos] = heap[path];
+                    ppos = path;
+                    path = path * 2 + 1;
+                }
+
+                /* Now propagate the last element down along path.  Normally
+                 * it shouldn't go too deep.
+                 */
+                int lastVal = values[last];
+                while ((path = ppos) > 0
+                        && values[heap[ppos = (path - 1) / 2]] > lastVal)
+                    heap[path] = heap[ppos];
+                heap[path] = last;
+
+
+                int second = heap[0];
+
+                /* Create a new node father of first and second */
+                last = numNodes++;
+                childs[2 * last] = first;
+                childs[2 * last + 1] = second;
+                int mindepth = Math.min(values[first] & 0xff, values[second] & 0xff);
+                values[last] = lastVal = values[first] + values[second] - mindepth + 1;
+
+                /* Again, propagate the hole to the leafs */
+                ppos = 0;
+                path = 1;
+                while (path < heapLen) {
+                    if (path + 1 < heapLen
+                            && values[heap[path]] > values[heap[path + 1]])
+                        path++;
+
+                    heap[ppos] = heap[path];
+                    ppos = path;
+                    path = ppos * 2 + 1;
+                }
+
+                /* Now propagate the new element down along path */
+                while ((path = ppos) > 0
+                        && values[heap[ppos = (path - 1) / 2]] > lastVal)
+                    heap[path] = heap[ppos];
+                heap[path] = last;
+            }
+            while (heapLen > 1);
+
+            if (heap[0] != childs.length / 2 - 1)
+                throw new RuntimeException("Weird!");
+
+            buildLength(childs);
+        }
+
+        int getEncodedLength() {
+            int len = 0;
+            for (int i = 0; i < freqs.length; i++)
+                len += freqs[i] * length[i];
+            return len;
+        }
+
+        void calcBLFreq(Tree blTree) {
+            int max_count;               /* max repeat count */
+            int min_count;               /* min repeat count */
+            int count;                   /* repeat count of the current code */
+            int curlen = -1;             /* length of current code */
+
+            int i = 0;
+            while (i < numCodes) {
+                count = 1;
+                int nextlen = length[i];
+                if (nextlen == 0) {
+                    max_count = 138;
+                    min_count = 3;
+                } else {
+                    max_count = 6;
+                    min_count = 3;
+                    if (curlen != nextlen) {
+                        blTree.freqs[nextlen]++;
+                        count = 0;
+                    }
+                }
+                curlen = nextlen;
+                i++;
+
+                while (i < numCodes && curlen == length[i]) {
+                    i++;
+                    if (++count >= max_count)
+                        break;
+                }
+
+                if (count < min_count)
+                    blTree.freqs[curlen] += count;
+                else if (curlen != 0)
+                    blTree.freqs[REP_3_6]++;
+                else if (count <= 10)
+                    blTree.freqs[REP_3_10]++;
+                else
+                    blTree.freqs[REP_11_138]++;
+            }
+        }
+
+        void writeTree(Tree blTree) {
+            int max_count;               /* max repeat count */
+            int min_count;               /* min repeat count */
+            int count;                   /* repeat count of the current code */
+            int curlen = -1;             /* length of current code */
+
+            int i = 0;
+            while (i < numCodes) {
+                count = 1;
+                int nextlen = length[i];
+                if (nextlen == 0) {
+                    max_count = 138;
+                    min_count = 3;
+                } else {
+                    max_count = 6;
+                    min_count = 3;
+                    if (curlen != nextlen) {
+                        blTree.writeSymbol(nextlen);
+                        count = 0;
+                    }
+                }
+                curlen = nextlen;
+                i++;
+
+                while (i < numCodes && curlen == length[i]) {
+                    i++;
+                    if (++count >= max_count)
+                        break;
+                }
+
+                if (count < min_count) {
+                    while (count-- > 0)
+                        blTree.writeSymbol(curlen);
+                } else if (curlen != 0) {
+                    blTree.writeSymbol(REP_3_6);
+                    pending.writeBits(count - 3, 2);
+                } else if (count <= 10) {
+                    blTree.writeSymbol(REP_3_10);
+                    pending.writeBits(count - 3, 3);
+                } else {
+                    blTree.writeSymbol(REP_11_138);
+                    pending.writeBits(count - 11, 7);
+                }
+            }
+        }
+    }
+
+
+    DeflaterPending pending;
+    private Tree literalTree, distTree, blTree;
+
+    private short d_buf[];
+    private byte l_buf[];
+    private int last_lit;
+    private int extra_bits;
+
+    private static short staticLCodes[];
+    private static byte staticLLength[];
+    private static short staticDCodes[];
+    private static byte staticDLength[];
+
+    /**
+     * Reverse the bits of a 16 bit value.
+     */
+    static short bitReverse(int value) {
+        return (short) (bit4Reverse.charAt(value & 0xf) << 12
+                | bit4Reverse.charAt((value >> 4) & 0xf) << 8
+                | bit4Reverse.charAt((value >> 8) & 0xf) << 4
+                | bit4Reverse.charAt(value >> 12));
+    }
+
+    static {
+        /* See RFC 1951 3.2.6 */
+        /* Literal codes */
+        staticLCodes = new short[LITERAL_NUM];
+        staticLLength = new byte[LITERAL_NUM];
+        int i = 0;
+        while (i < 144) {
+            staticLCodes[i] = bitReverse((0x030 + i) << 8);
+            staticLLength[i++] = 8;
+        }
+        while (i < 256) {
+            staticLCodes[i] = bitReverse((0x190 - 144 + i) << 7);
+            staticLLength[i++] = 9;
+        }
+        while (i < 280) {
+            staticLCodes[i] = bitReverse((0x000 - 256 + i) << 9);
+            staticLLength[i++] = 7;
+        }
+        while (i < LITERAL_NUM) {
+            staticLCodes[i] = bitReverse((0x0c0 - 280 + i) << 8);
+            staticLLength[i++] = 8;
+        }
+
+        /* Distant codes */
+        staticDCodes = new short[DIST_NUM];
+        staticDLength = new byte[DIST_NUM];
+        for (i = 0; i < DIST_NUM; i++) {
+            staticDCodes[i] = bitReverse(i << 11);
+            staticDLength[i] = 5;
+        }
+    }
+
+    public DeflaterHuffman(DeflaterPending pending) {
+        this.pending = pending;
+
+        literalTree = new Tree(LITERAL_NUM, 257, 15);
+        distTree = new Tree(DIST_NUM, 1, 15);
+        blTree = new Tree(BITLEN_NUM, 4, 7);
+
+        d_buf = new short[BUFSIZE];
+        l_buf = new byte[BUFSIZE];
+    }
+
+    public final void reset() {
+        last_lit = 0;
+        extra_bits = 0;
+        literalTree.reset();
+        distTree.reset();
+        blTree.reset();
+    }
+
+    private final int l_code(int len) {
+        if (len == 255)
+            return 285;
+
+        int code = 257;
+        while (len >= 8) {
+            code += 4;
+            len >>= 1;
+        }
+        return code + len;
+    }
+
+    private final int d_code(int distance) {
+        int code = 0;
+        while (distance >= 4) {
+            code += 2;
+            distance >>= 1;
+        }
+        return code + distance;
+    }
+
+    public void sendAllTrees(int blTreeCodes) {
+        blTree.buildCodes();
+        literalTree.buildCodes();
+        distTree.buildCodes();
+        pending.writeBits(literalTree.numCodes - 257, 5);
+        pending.writeBits(distTree.numCodes - 1, 5);
+        pending.writeBits(blTreeCodes - 4, 4);
+        for (int rank = 0; rank < blTreeCodes; rank++)
+            pending.writeBits(blTree.length[BL_ORDER[rank]], 3);
+        literalTree.writeTree(blTree);
+        distTree.writeTree(blTree);
+        if (DeflaterConstants.DEBUGGING)
+            blTree.checkEmpty();
+    }
+
+    public void compressBlock() {
+        for (int i = 0; i < last_lit; i++) {
+            int litlen = l_buf[i] & 0xff;
+            int dist = d_buf[i];
+            if (dist-- != 0) {
+                if (DeflaterConstants.DEBUGGING)
+                    System.err.print("[" + (dist + 1) + "," + (litlen + 3) + "]: ");
+
+                int lc = l_code(litlen);
+                literalTree.writeSymbol(lc);
+
+                int bits = (lc - 261) / 4;
+                if (bits > 0 && bits <= 5)
+                    pending.writeBits(litlen & ((1 << bits) - 1), bits);
+
+                int dc = d_code(dist);
+                distTree.writeSymbol(dc);
+
+                bits = dc / 2 - 1;
+                if (bits > 0)
+                    pending.writeBits(dist & ((1 << bits) - 1), bits);
+            } else {
+                if (DeflaterConstants.DEBUGGING) {
+                    if (litlen > 32 && litlen < 127)
+                        System.err.print("(" + (char) litlen + "): ");
+                    else
+                        System.err.print("{" + litlen + "}: ");
+                }
+                literalTree.writeSymbol(litlen);
+            }
+        }
+        if (DeflaterConstants.DEBUGGING)
+            System.err.print("EOF: ");
+        literalTree.writeSymbol(EOF_SYMBOL);
+        if (DeflaterConstants.DEBUGGING) {
+            literalTree.checkEmpty();
+            distTree.checkEmpty();
+        }
+    }
+
+    public void flushStoredBlock(byte[] stored,
+                                 int stored_offset, int stored_len,
+                                 boolean lastBlock) {
+        if (DeflaterConstants.DEBUGGING)
+            System.err.println("Flushing stored block " + stored_len);
+        pending.writeBits((DeflaterConstants.STORED_BLOCK << 1)
+                + (lastBlock ? 1 : 0), 3);
+        pending.alignToByte();
+        pending.writeShort(stored_len);
+        pending.writeShort(~stored_len);
+        pending.writeBlock(stored, stored_offset, stored_len);
+        reset();
+    }
+
+    public void flushBlock(byte[] stored, int stored_offset, int stored_len,
+                           boolean lastBlock) {
+        literalTree.freqs[EOF_SYMBOL]++;
+
+        /* Build trees */
+        literalTree.buildTree();
+        distTree.buildTree();
+
+        /* Calculate bitlen frequency */
+        literalTree.calcBLFreq(blTree);
+        distTree.calcBLFreq(blTree);
+
+        /* Build bitlen tree */
+        blTree.buildTree();
+
+        int blTreeCodes = 4;
+        for (int i = 18; i > blTreeCodes; i--) {
+            if (blTree.length[BL_ORDER[i]] > 0)
+                blTreeCodes = i + 1;
+        }
+        int opt_len = 14 + blTreeCodes * 3 + blTree.getEncodedLength()
+                + literalTree.getEncodedLength() + distTree.getEncodedLength()
+                + extra_bits;
+
+        int static_len = extra_bits;
+        for (int i = 0; i < LITERAL_NUM; i++)
+            static_len += literalTree.freqs[i] * staticLLength[i];
+        for (int i = 0; i < DIST_NUM; i++)
+            static_len += distTree.freqs[i] * staticDLength[i];
+        if (opt_len >= static_len) {
+            /* Force static trees */
+            opt_len = static_len;
+        }
+
+        if (stored_offset >= 0 && stored_len + 4 < opt_len >> 3) {
+            /* Store Block */
+            if (DeflaterConstants.DEBUGGING)
+                System.err.println("Storing, since " + stored_len + " < " + opt_len
+                        + " <= " + static_len);
+            flushStoredBlock(stored, stored_offset, stored_len, lastBlock);
+        } else if (opt_len == static_len) {
+            /* Encode with static tree */
+            pending.writeBits((DeflaterConstants.STATIC_TREES << 1)
+                    + (lastBlock ? 1 : 0), 3);
+            literalTree.setStaticCodes(staticLCodes, staticLLength);
+            distTree.setStaticCodes(staticDCodes, staticDLength);
+            compressBlock();
+            reset();
+        } else {
+            /* Encode with dynamic tree */
+            pending.writeBits((DeflaterConstants.DYN_TREES << 1)
+                    + (lastBlock ? 1 : 0), 3);
+            sendAllTrees(blTreeCodes);
+            compressBlock();
+            reset();
+        }
+    }
+
+    public final boolean isFull() {
+        return last_lit == BUFSIZE;
+    }
+
+    public final boolean tallyLit(int lit) {
+        if (DeflaterConstants.DEBUGGING) {
+            if (lit > 32 && lit < 127)
+                System.err.println("(" + (char) lit + ")");
+            else
+                System.err.println("{" + lit + "}");
+        }
+        d_buf[last_lit] = 0;
+        l_buf[last_lit++] = (byte) lit;
+        literalTree.freqs[lit]++;
+        return last_lit == BUFSIZE;
+    }
+
+    public final boolean tallyDist(int dist, int len) {
+        if (DeflaterConstants.DEBUGGING)
+            System.err.println("[" + dist + "," + len + "]");
+
+        d_buf[last_lit] = (short) dist;
+        l_buf[last_lit++] = (byte) (len - 3);
+
+        int lc = l_code(len - 3);
+        literalTree.freqs[lc]++;
+        if (lc >= 265 && lc < 285)
+            extra_bits += (lc - 261) / 4;
+
+        int dc = d_code(dist - 1);
+        distTree.freqs[dc]++;
+        if (dc >= 4)
+            extra_bits += dc / 2 - 1;
+        return last_lit == BUFSIZE;
+    }
+}

epublib/src/main/java/me/ag2s/epublib/zip/DeflaterOutputStream.java

@@ -0,0 +1,190 @@
+/* DeflaterOutputStream.java - Output filter for compressing.
+   Copyright (C) 1999, 2000, 2001, 2004 Free Software Foundation, Inc.
+
+This file is part of GNU Classpath.
+
+GNU Classpath is free software; you can redistribute it and/or modify
+it under the terms of the GNU General Public License as published by
+the Free Software Foundation; either version 2, or (at your option)
+any later version.
+
+GNU Classpath is distributed in the hope that it will be useful, but
+WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+General Public License for more details.
+
+You should have received a copy of the GNU General Public License
+along with GNU Classpath; see the file COPYING.  If not, write to the
+Free Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
+02111-1307 USA.
+
+Linking this library statically or dynamically with other modules is
+making a combined work based on this library.  Thus, the terms and
+conditions of the GNU General Public License cover the whole
+combination.
+
+As a special exception, the copyright holders of this library give you
+permission to link this library with independent modules to produce an
+executable, regardless of the license terms of these independent
+modules, and to copy and distribute the resulting executable under
+terms of your choice, provided that you also meet, for each linked
+independent module, the terms and conditions of the license of that
+module.  An independent module is a module which is not derived from
+or based on this library.  If you modify this library, you may extend
+this exception to your version of the library, but you are not
+obligated to do so.  If you do not wish to do so, delete this
+exception statement from your version. */
+
+package me.ag2s.epublib.zip;
+
+import java.io.FilterOutputStream;
+import java.io.IOException;
+import java.io.OutputStream;
+
+/* Written using on-line Java Platform 1.2 API Specification
+ * and JCL book.
+ * Believed complete and correct.
+ */
+
+/**
+ * This is a special FilterOutputStream deflating the bytes that are
+ * written through it.  It uses the Deflater for deflating.
+ * <p>
+ * A special thing to be noted is that flush() doesn't flush
+ * everything in Sun's JDK, but it does so in jazzlib. This is because
+ * Sun's Deflater doesn't have a way to flush() everything, without
+ * finishing the stream.
+ *
+ * @author Tom Tromey, Jochen Hoenicke
+ * @date Jan 11, 2001
+ */
+public class DeflaterOutputStream extends FilterOutputStream {
+  /**
+   * This buffer is used temporarily to retrieve the bytes from the
+   * deflater and write them to the underlying output stream.
+   */
+  protected byte[] buf;
+
+  /**
+   * The deflater which is used to deflate the stream.
+   */
+  protected Deflater def;
+
+  /**
+   * Deflates everything in the def's input buffers.  This will call
+   * <code>def.deflate()</code> until all bytes from the input buffers
+   * are processed.
+   */
+  protected void deflate() throws IOException {
+    while (!def.needsInput()) {
+      int len = def.deflate(buf, 0, buf.length);
+
+      //	System.err.println("DOS deflated " + len + " out of " + buf.length);
+      if (len <= 0)
+        break;
+      out.write(buf, 0, len);
+    }
+
+    if (!def.needsInput())
+      throw new InternalError("Can't deflate all input?");
+  }
+
+  /**
+   * Creates a new DeflaterOutputStream with a default Deflater and
+   * default buffer size.
+   *
+   * @param out the output stream where deflated output should be written.
+   */
+  public DeflaterOutputStream(OutputStream out) {
+    this(out, new Deflater(), 512);
+  }
+
+  /**
+   * Creates a new DeflaterOutputStream with the given Deflater and
+   * default buffer size.
+   *
+   * @param out  the output stream where deflated output should be written.
+   * @param defl the underlying deflater.
+   */
+  public DeflaterOutputStream(OutputStream out, Deflater defl) {
+    this(out, defl, 512);
+  }
+
+  /**
+   * Creates a new DeflaterOutputStream with the given Deflater and
+   * buffer size.
+   *
+   * @param out     the output stream where deflated output should be written.
+   * @param defl    the underlying deflater.
+   * @param bufsize the buffer size.
+   * @throws IllegalArgumentException if bufsize isn't positive.
+   */
+  public DeflaterOutputStream(OutputStream out, Deflater defl, int bufsize) {
+    super(out);
+    if (bufsize <= 0)
+      throw new IllegalArgumentException("bufsize <= 0");
+    buf = new byte[bufsize];
+    def = defl;
+  }
+
+  /**
+   * Flushes the stream by calling flush() on the deflater and then
+   * on the underlying stream.  This ensures that all bytes are
+   * flushed.  This function doesn't work in Sun's JDK, but only in
+   * jazzlib.
+   */
+  public void flush() throws IOException {
+    def.flush();
+    deflate();
+    out.flush();
+  }
+
+  /**
+   * Finishes the stream by calling finish() on the deflater.  This
+   * was the only way to ensure that all bytes are flushed in Sun's
+   * JDK.
+   */
+  public void finish() throws IOException {
+    def.finish();
+    while (!def.finished()) {
+      int len = def.deflate(buf, 0, buf.length);
+      if (len <= 0)
+        break;
+      out.write(buf, 0, len);
+    }
+    if (!def.finished())
+      throw new InternalError("Can't deflate all input?");
+    out.flush();
+  }
+
+  /**
+   * Calls finish () and closes the stream.
+   */
+  public void close() throws IOException {
+    finish();
+    out.close();
+  }
+
+  /**
+   * Writes a single byte to the compressed output stream.
+   *
+   * @param bval the byte value.
+   */
+  public void write(int bval) throws IOException {
+    byte[] b = new byte[1];
+    b[0] = (byte) bval;
+    write(b, 0, 1);
+  }
+
+  /**
+   * Writes a len bytes from an array to the compressed stream.
+   *
+   * @param buf the byte array.
+   * @param off the offset into the byte array where to start.
+   * @param len the number of bytes to write.
+   */
+  public void write(byte[] buf, int off, int len) throws IOException {
+    def.setInput(buf, off, len);
+    deflate();
+  }
+}

epublib/src/main/java/me/ag2s/epublib/zip/DeflaterPending.java

@@ -0,0 +1,52 @@
+/* me.ag2s.epublib.zip.DeflaterPending
+   Copyright (C) 2001 Free Software Foundation, Inc.
+
+This file is part of GNU Classpath.
+
+GNU Classpath is free software; you can redistribute it and/or modify
+it under the terms of the GNU General Public License as published by
+the Free Software Foundation; either version 2, or (at your option)
+any later version.
+
+GNU Classpath is distributed in the hope that it will be useful, but
+WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+General Public License for more details.
+
+You should have received a copy of the GNU General Public License
+along with GNU Classpath; see the file COPYING.  If not, write to the
+Free Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
+02111-1307 USA.
+
+Linking this library statically or dynamically with other modules is
+making a combined work based on this library.  Thus, the terms and
+conditions of the GNU General Public License cover the whole
+combination.
+
+As a special exception, the copyright holders of this library give you
+permission to link this library with independent modules to produce an
+executable, regardless of the license terms of these independent
+modules, and to copy and distribute the resulting executable under
+terms of your choice, provided that you also meet, for each linked
+independent module, the terms and conditions of the license of that
+module.  An independent module is a module which is not derived from
+or based on this library.  If you modify this library, you may extend
+this exception to your version of the library, but you are not
+obligated to do so.  If you do not wish to do so, delete this
+exception statement from your version. */
+
+package me.ag2s.epublib.zip;
+
+/**
+ * This class stores the pending output of the Deflater.
+ *
+ * @author Jochen Hoenicke
+ * @date Jan 5, 2000
+ */
+
+class DeflaterPending extends PendingBuffer {
+    public DeflaterPending() {
+        super(DeflaterConstants.PENDING_BUF_SIZE);
+    }
+}
+

epublib/src/main/java/me/ag2s/epublib/zip/GZIPInputStream.java

@@ -0,0 +1,338 @@
+/* GZIPInputStream.java - Input filter for reading gzip file
+   Copyright (C) 1999, 2000, 2001, 2002, 2004 Free Software Foundation, Inc.
+
+This file is part of GNU Classpath.
+
+GNU Classpath is free software; you can redistribute it and/or modify
+it under the terms of the GNU General Public License as published by
+the Free Software Foundation; either version 2, or (at your option)
+any later version.
+ 
+GNU Classpath is distributed in the hope that it will be useful, but
+WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+General Public License for more details.
+
+You should have received a copy of the GNU General Public License
+along with GNU Classpath; see the file COPYING.  If not, write to the
+Free Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
+02111-1307 USA.
+
+Linking this library statically or dynamically with other modules is
+making a combined work based on this library.  Thus, the terms and
+conditions of the GNU General Public License cover the whole
+combination.
+
+As a special exception, the copyright holders of this library give you
+permission to link this library with independent modules to produce an
+executable, regardless of the license terms of these independent
+modules, and to copy and distribute the resulting executable under
+terms of your choice, provided that you also meet, for each linked
+independent module, the terms and conditions of the license of that
+module.  An independent module is a module which is not derived from
+or based on this library.  If you modify this library, you may extend
+this exception to your version of the library, but you are not
+obligated to do so.  If you do not wish to do so, delete this
+exception statement from your version. */
+
+package me.ag2s.epublib.zip;
+
+import java.io.EOFException;
+import java.io.IOException;
+import java.io.InputStream;
+
+/**
+ * This filter stream is used to decompress a "GZIP" format stream.
+ * The "GZIP" format is described in RFC 1952.
+ *
+ * @author John Leuner
+ * @author Tom Tromey
+ * @since JDK 1.1
+ */
+public class GZIPInputStream
+        extends InflaterInputStream {
+  /**
+   * The magic number found at the start of a GZIP stream.
+   */
+  public static final int GZIP_MAGIC = 0x1f8b;
+
+  /**
+   * The mask for bit 0 of the flag byte.
+   */
+  static final int FTEXT = 0x1;
+
+  /**
+   * The mask for bit 1 of the flag byte.
+   */
+  static final int FHCRC = 0x2;
+
+  /**
+   * The mask for bit 2 of the flag byte.
+   */
+  static final int FEXTRA = 0x4;
+
+  /**
+   * The mask for bit 3 of the flag byte.
+   */
+  static final int FNAME = 0x8;
+
+  /**
+   * The mask for bit 4 of the flag byte.
+   */
+  static final int FCOMMENT = 0x10;
+
+  /**
+   * The CRC-32 checksum value for uncompressed data.
+   */
+  protected CRC32 crc;
+
+  /**
+   * Indicates whether or not the end of the stream has been reached.
+   */
+  protected boolean eos;
+
+  /**
+   * Indicates whether or not the GZIP header has been read in.
+   */
+  private boolean readGZIPHeader;
+
+  /**
+   * Creates a GZIPInputStream with the default buffer size.
+   *
+   * @param in The stream to read compressed data from
+   *           (in GZIP format).
+   * @throws IOException if an error occurs during an I/O operation.
+   */
+  public GZIPInputStream(InputStream in)
+          throws IOException {
+    this(in, 4096);
+  }
+
+  /**
+   * Creates a GZIPInputStream with the specified buffer size.
+   *
+   * @param in   The stream to read compressed data from
+   *             (in GZIP format).
+   * @param size The size of the buffer to use.
+   * @throws IOException              if an error occurs during an I/O operation.
+   * @throws IllegalArgumentException if <code>size</code>
+   *                                  is less than or equal to 0.
+   */
+  public GZIPInputStream(InputStream in, int size)
+          throws IOException {
+    super(in, new Inflater(true), size);
+    crc = new CRC32();
+  }
+
+  /**
+   * Closes the input stream.
+   *
+   * @throws IOException if an error occurs during an I/O operation.
+   */
+  public void close()
+          throws IOException {
+    // Nothing to do here.
+    super.close();
+  }
+
+  /**
+   * Reads in GZIP-compressed data and stores it in uncompressed form
+   * into an array of bytes.  The method will block until either
+   * enough input data becomes available or the compressed stream
+   * reaches its end.
+   *
+   * @param buf    the buffer into which the uncompressed data will
+   *               be stored.
+   * @param offset the offset indicating where in <code>buf</code>
+   *               the uncompressed data should be placed.
+   * @param len    the number of uncompressed bytes to be read.
+   */
+  public int read(byte[] buf, int offset, int len) throws IOException {
+    // We first have to slurp in the GZIP header, then we feed all the
+    // rest of the data to the superclass.
+    //
+    // As we do that we continually update the CRC32. Once the data is
+    // finished, we check the CRC32.
+    //
+    // This means we don't need our own buffer, as everything is done
+    // in the superclass.
+    if (!readGZIPHeader)
+      readHeader();
+
+    if (eos)
+      return -1;
+
+    //  System.err.println("GZIPIS.read(byte[], off, len ... " + offset + " and len " + len);
+
+    /* We don't have to read the header,
+     * so we just grab data from the superclass.
+     */
+    int numRead = super.read(buf, offset, len);
+    if (numRead > 0)
+      crc.update(buf, offset, numRead);
+
+    if (inf.finished())
+      readFooter();
+    return numRead;
+  }
+
+
+  /**
+   * Reads in the GZIP header.
+   */
+  private void readHeader() throws IOException {
+    /* 1. Check the two magic bytes */
+    CRC32 headCRC = new CRC32();
+    int magic = in.read();
+    if (magic < 0) {
+      eos = true;
+      return;
+    }
+    headCRC.update(magic);
+    if (magic != (GZIP_MAGIC >> 8))
+      throw new IOException("Error in GZIP header, first byte doesn't match");
+
+    magic = in.read();
+    if (magic != (GZIP_MAGIC & 0xff))
+      throw new IOException("Error in GZIP header, second byte doesn't match");
+    headCRC.update(magic);
+
+    /* 2. Check the compression type (must be 8) */
+    int CM = in.read();
+    if (CM != 8)
+      throw new IOException("Error in GZIP header, data not in deflate format");
+    headCRC.update(CM);
+
+    /* 3. Check the flags */
+    int flags = in.read();
+    if (flags < 0)
+      throw new EOFException("Early EOF in GZIP header");
+    headCRC.update(flags);
+    
+    /*    This flag byte is divided into individual bits as follows:
+	  
+	  bit 0   FTEXT
+	  bit 1   FHCRC
+	  bit 2   FEXTRA
+	  bit 3   FNAME
+	  bit 4   FCOMMENT
+	  bit 5   reserved
+	  bit 6   reserved
+	  bit 7   reserved
+    */
+
+    /* 3.1 Check the reserved bits are zero */
+    if ((flags & 0xd0) != 0)
+      throw new IOException("Reserved flag bits in GZIP header != 0");
+
+    /* 4.-6. Skip the modification time, extra flags, and OS type */
+    for (int i = 0; i < 6; i++) {
+      int readByte = in.read();
+      if (readByte < 0)
+        throw new EOFException("Early EOF in GZIP header");
+      headCRC.update(readByte);
+    }
+
+    /* 7. Read extra field */
+    if ((flags & FEXTRA) != 0) {
+      /* Skip subfield id */
+      for (int i = 0; i < 2; i++) {
+        int readByte = in.read();
+        if (readByte < 0)
+          throw new EOFException("Early EOF in GZIP header");
+        headCRC.update(readByte);
+      }
+      if (in.read() < 0 || in.read() < 0)
+        throw new EOFException("Early EOF in GZIP header");
+
+      int len1, len2, extraLen;
+      len1 = in.read();
+      len2 = in.read();
+      if ((len1 < 0) || (len2 < 0))
+        throw new EOFException("Early EOF in GZIP header");
+      headCRC.update(len1);
+      headCRC.update(len2);
+
+      extraLen = (len1 << 8) | len2;
+      for (int i = 0; i < extraLen; i++) {
+        int readByte = in.read();
+        if (readByte < 0)
+          throw new EOFException("Early EOF in GZIP header");
+        headCRC.update(readByte);
+      }
+    }
+
+    /* 8. Read file name */
+    if ((flags & FNAME) != 0) {
+      int readByte;
+      while ((readByte = in.read()) > 0)
+        headCRC.update(readByte);
+      if (readByte < 0)
+        throw new EOFException("Early EOF in GZIP file name");
+      headCRC.update(readByte);
+    }
+
+    /* 9. Read comment */
+    if ((flags & FCOMMENT) != 0) {
+      int readByte;
+      while ((readByte = in.read()) > 0)
+        headCRC.update(readByte);
+
+      if (readByte < 0)
+        throw new EOFException("Early EOF in GZIP comment");
+      headCRC.update(readByte);
+    }
+
+    /* 10. Read header CRC */
+    if ((flags & FHCRC) != 0) {
+      int tempByte;
+      int crcval = in.read();
+      if (crcval < 0)
+        throw new EOFException("Early EOF in GZIP header");
+
+      tempByte = in.read();
+      if (tempByte < 0)
+        throw new EOFException("Early EOF in GZIP header");
+
+      crcval = (crcval << 8) | tempByte;
+      if (crcval != ((int) headCRC.getValue() & 0xffff))
+        throw new IOException("Header CRC value mismatch");
+    }
+
+    readGZIPHeader = true;
+    //System.err.println("Read GZIP header");
+  }
+
+  private void readFooter() throws IOException {
+    byte[] footer = new byte[8];
+    int avail = inf.getRemaining();
+    if (avail > 8)
+      avail = 8;
+    System.arraycopy(buf, len - inf.getRemaining(), footer, 0, avail);
+    int needed = 8 - avail;
+    while (needed > 0) {
+      int count = in.read(footer, 8 - needed, needed);
+      if (count <= 0)
+        throw new EOFException("Early EOF in GZIP footer");
+      needed -= count; //Jewel Jan 16
+    }
+
+    int crcval = (footer[0] & 0xff) | ((footer[1] & 0xff) << 8)
+            | ((footer[2] & 0xff) << 16) | (footer[3] << 24);
+    if (crcval != (int) crc.getValue())
+      throw new IOException("GZIP crc sum mismatch, theirs \""
+              + Integer.toHexString(crcval)
+              + "\" and ours \""
+              + Integer.toHexString((int) crc.getValue()));
+
+    int total = (footer[4] & 0xff) | ((footer[5] & 0xff) << 8)
+            | ((footer[6] & 0xff) << 16) | (footer[7] << 24);
+    if (total != inf.getTotalOut())
+      throw new IOException("Number of bytes mismatch");
+
+    /* FIXME" XXX Should we support multiple members.
+     * Difficult, since there may be some bytes still in buf
+     */
+    eos = true;
+  }
+}

epublib/src/main/java/me/ag2s/epublib/zip/GZIPOutputStream.java

@@ -0,0 +1,146 @@
+/* GZIPOutputStream.java - Create a file in gzip format
+   Copyright (C) 1999, 2000, 2001 Free Software Foundation, Inc.
+
+This file is part of GNU Classpath.
+
+GNU Classpath is free software; you can redistribute it and/or modify
+it under the terms of the GNU General Public License as published by
+the Free Software Foundation; either version 2, or (at your option)
+any later version.
+ 
+GNU Classpath is distributed in the hope that it will be useful, but
+WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+General Public License for more details.
+
+You should have received a copy of the GNU General Public License
+along with GNU Classpath; see the file COPYING.  If not, write to the
+Free Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
+02111-1307 USA.
+
+Linking this library statically or dynamically with other modules is
+making a combined work based on this library.  Thus, the terms and
+conditions of the GNU General Public License cover the whole
+combination.
+
+As a special exception, the copyright holders of this library give you
+permission to link this library with independent modules to produce an
+executable, regardless of the license terms of these independent
+modules, and to copy and distribute the resulting executable under
+terms of your choice, provided that you also meet, for each linked
+independent module, the terms and conditions of the license of that
+module.  An independent module is a module which is not derived from
+or based on this library.  If you modify this library, you may extend
+this exception to your version of the library, but you are not
+obligated to do so.  If you do not wish to do so, delete this
+exception statement from your version. */
+
+package me.ag2s.epublib.zip;
+
+import java.io.IOException;
+import java.io.OutputStream;
+
+/**
+ * This filter stream is used to compress a stream into a "GZIP" stream.
+ * The "GZIP" format is described in RFC 1952.
+ *
+ * @author John Leuner
+ * @author Tom Tromey
+ * @since JDK 1.1
+ */
+
+/* Written using on-line Java Platform 1.2 API Specification
+ * and JCL book.
+ * Believed complete and correct.
+ */
+
+public class GZIPOutputStream extends DeflaterOutputStream {
+    /**
+     * CRC-32 value for uncompressed data
+     */
+    protected CRC32 crc;
+
+    /* Creates a GZIPOutputStream with the default buffer size
+     *
+     *
+     * @param out The stream to read data (to be compressed) from
+     *
+     */
+    public GZIPOutputStream(OutputStream out) throws IOException {
+        this(out, 4096);
+    }
+
+    /**
+     * Creates a GZIPOutputStream with the specified buffer size
+     *
+     * @param out  The stream to read compressed data from
+     * @param size Size of the buffer to use
+     */
+    public GZIPOutputStream(OutputStream out, int size) throws IOException {
+        super(out, new Deflater(Deflater.DEFAULT_COMPRESSION, true), size);
+
+        crc = new CRC32();
+        int mod_time = (int) (System.currentTimeMillis() / 1000L);
+        byte[] gzipHeader =
+                {
+                        /* The two magic bytes */
+                        (byte) (GZIPInputStream.GZIP_MAGIC >> 8),
+                        (byte) GZIPInputStream.GZIP_MAGIC,
+
+                        /* The compression type */
+                        (byte) Deflater.DEFLATED,
+
+                        /* The flags (not set) */
+                        0,
+
+                        /* The modification time */
+                        (byte) mod_time, (byte) (mod_time >> 8),
+                        (byte) (mod_time >> 16), (byte) (mod_time >> 24),
+
+                        /* The extra flags */
+                        0,
+
+                        /* The OS type (unknown) */
+                        (byte) 255
+                };
+
+        out.write(gzipHeader);
+        //    System.err.println("wrote GZIP header (" + gzipHeader.length + " bytes )");
+    }
+
+    public synchronized void write(byte[] buf, int off, int len)
+            throws IOException {
+        super.write(buf, off, len);
+        crc.update(buf, off, len);
+    }
+
+    /**
+     * Writes remaining compressed output data to the output stream
+     * and closes it.
+     */
+    public void close() throws IOException {
+        finish();
+        out.close();
+    }
+
+    public void finish() throws IOException {
+        super.finish();
+
+        int totalin = def.getTotalIn();
+        int crcval = (int) (crc.getValue() & 0xffffffff);
+
+        //    System.err.println("CRC val is " + Integer.toHexString( crcval ) 		       + " and length " + Integer.toHexString(totalin));
+
+        byte[] gzipFooter =
+                {
+                        (byte) crcval, (byte) (crcval >> 8),
+                        (byte) (crcval >> 16), (byte) (crcval >> 24),
+
+                        (byte) totalin, (byte) (totalin >> 8),
+                        (byte) (totalin >> 16), (byte) (totalin >> 24)
+                };
+
+        out.write(gzipFooter);
+        //    System.err.println("wrote GZIP trailer (" + gzipFooter.length + " bytes )");
+    }
+}

epublib/src/main/java/me/ag2s/epublib/zip/Inflater.java

@@ -0,0 +1,681 @@
+/* Inflater.java - Decompress a data stream
+   Copyright (C) 1999, 2000, 2001, 2003  Free Software Foundation, Inc.
+
+This file is part of GNU Classpath.
+
+GNU Classpath is free software; you can redistribute it and/or modify
+it under the terms of the GNU General Public License as published by
+the Free Software Foundation; either version 2, or (at your option)
+any later version.
+ 
+GNU Classpath is distributed in the hope that it will be useful, but
+WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+General Public License for more details.
+
+You should have received a copy of the GNU General Public License
+along with GNU Classpath; see the file COPYING.  If not, write to the
+Free Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
+02111-1307 USA.
+
+Linking this library statically or dynamically with other modules is
+making a combined work based on this library.  Thus, the terms and
+conditions of the GNU General Public License cover the whole
+combination.
+
+As a special exception, the copyright holders of this library give you
+permission to link this library with independent modules to produce an
+executable, regardless of the license terms of these independent
+modules, and to copy and distribute the resulting executable under
+terms of your choice, provided that you also meet, for each linked
+independent module, the terms and conditions of the license of that
+module.  An independent module is a module which is not derived from
+or based on this library.  If you modify this library, you may extend
+this exception to your version of the library, but you are not
+obligated to do so.  If you do not wish to do so, delete this
+exception statement from your version. */
+
+package me.ag2s.epublib.zip;
+
+/* Written using on-line Java Platform 1.2 API Specification
+ * and JCL book.
+ * Believed complete and correct.
+ */
+
+/**
+ * Inflater is used to decompress data that has been compressed according
+ * to the "deflate" standard described in rfc1950.
+ * <p>
+ * The usage is as following.  First you have to set some input with
+ * <code>setInput()</code>, then inflate() it.  If inflate doesn't
+ * inflate any bytes there may be three reasons:
+ * <ul>
+ * <li>needsInput() returns true because the input buffer is empty.
+ * You have to provide more input with <code>setInput()</code>.
+ * NOTE: needsInput() also returns true when, the stream is finished.
+ * </li>
+ * <li>needsDictionary() returns true, you have to provide a preset
+ *     dictionary with <code>setDictionary()</code>.</li>
+ * <li>finished() returns true, the inflater has finished.</li>
+ * </ul>
+ * Once the first output byte is produced, a dictionary will not be
+ * needed at a later stage.
+ *
+ * @author John Leuner, Jochen Hoenicke
+ * @author Tom Tromey
+ * @date May 17, 1999
+ * @since JDK 1.1
+ */
+public class Inflater {
+    /* Copy lengths for literal codes 257..285 */
+    private static final int CPLENS[] =
+            {
+                    3, 4, 5, 6, 7, 8, 9, 10, 11, 13, 15, 17, 19, 23, 27, 31,
+                    35, 43, 51, 59, 67, 83, 99, 115, 131, 163, 195, 227, 258
+            };
+
+    /* Extra bits for literal codes 257..285 */
+    private static final int CPLEXT[] =
+            {
+                    0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 1, 1, 2, 2, 2, 2,
+                    3, 3, 3, 3, 4, 4, 4, 4, 5, 5, 5, 5, 0
+            };
+
+    /* Copy offsets for distance codes 0..29 */
+    private static final int CPDIST[] = {
+            1, 2, 3, 4, 5, 7, 9, 13, 17, 25, 33, 49, 65, 97, 129, 193,
+            257, 385, 513, 769, 1025, 1537, 2049, 3073, 4097, 6145,
+            8193, 12289, 16385, 24577
+    };
+
+    /* Extra bits for distance codes */
+    private static final int CPDEXT[] = {
+            0, 0, 0, 0, 1, 1, 2, 2, 3, 3, 4, 4, 5, 5, 6, 6,
+            7, 7, 8, 8, 9, 9, 10, 10, 11, 11,
+            12, 12, 13, 13
+    };
+
+    /* This are the state in which the inflater can be.  */
+    private static final int DECODE_HEADER = 0;
+    private static final int DECODE_DICT = 1;
+    private static final int DECODE_BLOCKS = 2;
+    private static final int DECODE_STORED_LEN1 = 3;
+    private static final int DECODE_STORED_LEN2 = 4;
+    private static final int DECODE_STORED = 5;
+    private static final int DECODE_DYN_HEADER = 6;
+    private static final int DECODE_HUFFMAN = 7;
+    private static final int DECODE_HUFFMAN_LENBITS = 8;
+    private static final int DECODE_HUFFMAN_DIST = 9;
+    private static final int DECODE_HUFFMAN_DISTBITS = 10;
+    private static final int DECODE_CHKSUM = 11;
+    private static final int FINISHED = 12;
+
+    /**
+     * This variable contains the current state.
+     */
+    private int mode;
+
+    /**
+     * The adler checksum of the dictionary or of the decompressed
+     * stream, as it is written in the header resp. footer of the
+     * compressed stream.  <br>
+     * <p>
+     * Only valid if mode is DECODE_DICT or DECODE_CHKSUM.
+     */
+    private int readAdler;
+    /**
+     * The number of bits needed to complete the current state.  This
+     * is valid, if mode is DECODE_DICT, DECODE_CHKSUM,
+     * DECODE_HUFFMAN_LENBITS or DECODE_HUFFMAN_DISTBITS.
+     */
+    private int neededBits;
+    private int repLength, repDist;
+    private int uncomprLen;
+    /**
+     * True, if the last block flag was set in the last block of the
+     * inflated stream.  This means that the stream ends after the
+     * current block.
+     */
+    private boolean isLastBlock;
+
+    /**
+     * The total number of inflated bytes.
+     */
+    private int totalOut;
+    /**
+     * The total number of bytes set with setInput().  This is not the
+     * value returned by getTotalIn(), since this also includes the
+     * unprocessed input.
+     */
+    private int totalIn;
+    /**
+     * This variable stores the nowrap flag that was given to the constructor.
+     * True means, that the inflated stream doesn't contain a header nor the
+     * checksum in the footer.
+     */
+    private boolean nowrap;
+
+    private StreamManipulator input;
+    private OutputWindow outputWindow;
+    private InflaterDynHeader dynHeader;
+    private InflaterHuffmanTree litlenTree, distTree;
+    private Adler32 adler;
+
+    /**
+     * Creates a new inflater.
+     */
+    public Inflater() {
+        this(false);
+    }
+
+    /**
+     * Creates a new inflater.
+     *
+     * @param nowrap true if no header and checksum field appears in the
+     *               stream.  This is used for GZIPed input.  For compatibility with
+     *               Sun JDK you should provide one byte of input more than needed in
+     *               this case.
+     */
+    public Inflater(boolean nowrap) {
+        this.nowrap = nowrap;
+        this.adler = new Adler32();
+        input = new StreamManipulator();
+        outputWindow = new OutputWindow();
+        mode = nowrap ? DECODE_BLOCKS : DECODE_HEADER;
+    }
+
+    /**
+     * Finalizes this object.
+     */
+    protected void finalize() {
+        /* Exists only for compatibility */
+    }
+
+    /**
+     * Frees all objects allocated by the inflater.  There's no reason
+     * to call this, since you can just rely on garbage collection (even
+     * for the Sun implementation).  Exists only for compatibility
+     * with Sun's JDK, where the compressor allocates native memory.
+     * If you call any method (even reset) afterwards the behaviour is
+     * <i>undefined</i>.
+     *
+     * @deprecated Just clear all references to inflater instead.
+     */
+    public void end() {
+        outputWindow = null;
+        input = null;
+        dynHeader = null;
+        litlenTree = null;
+        distTree = null;
+        adler = null;
+    }
+
+    /**
+     * Returns true, if the inflater has finished.  This means, that no
+     * input is needed and no output can be produced.
+     */
+    public boolean finished() {
+        return mode == FINISHED && outputWindow.getAvailable() == 0;
+    }
+
+    /**
+     * Gets the adler checksum.  This is either the checksum of all
+     * uncompressed bytes returned by inflate(), or if needsDictionary()
+     * returns true (and thus no output was yet produced) this is the
+     * adler checksum of the expected dictionary.
+     *
+     * @returns the adler checksum.
+     */
+    public int getAdler() {
+        return needsDictionary() ? readAdler : (int) adler.getValue();
+    }
+
+    /**
+     * Gets the number of unprocessed input.  Useful, if the end of the
+     * stream is reached and you want to further process the bytes after
+     * the deflate stream.
+     *
+     * @return the number of bytes of the input which were not processed.
+     */
+    public int getRemaining() {
+        return input.getAvailableBytes();
+    }
+
+    /**
+     * Gets the total number of processed compressed input bytes.
+     *
+     * @return the total number of bytes of processed input bytes.
+     */
+    public int getTotalIn() {
+        return totalIn - getRemaining();
+    }
+
+    /**
+     * Gets the total number of output bytes returned by inflate().
+     *
+     * @return the total number of output bytes.
+     */
+    public int getTotalOut() {
+        return totalOut;
+    }
+
+    /**
+     * Inflates the compressed stream to the output buffer.  If this
+     * returns 0, you should check, whether needsDictionary(),
+     * needsInput() or finished() returns true, to determine why no
+     * further output is produced.
+     *
+     * @param buffer the output buffer.
+     * @return the number of bytes written to the buffer, 0 if no further
+     * output can be produced.
+     * @throws DataFormatException      if deflated stream is invalid.
+     * @throws IllegalArgumentException if buf has length 0.
+     */
+    public int inflate(byte[] buf) throws DataFormatException {
+        return inflate(buf, 0, buf.length);
+    }
+
+    /**
+     * Inflates the compressed stream to the output buffer.  If this
+     * returns 0, you should check, whether needsDictionary(),
+     * needsInput() or finished() returns true, to determine why no
+     * further output is produced.
+     *
+     * @param buffer the output buffer.
+     * @param off    the offset into buffer where the output should start.
+     * @param len    the maximum length of the output.
+     * @return the number of bytes written to the buffer, 0 if no further
+     * output can be produced.
+     * @throws DataFormatException       if deflated stream is invalid.
+     * @throws IndexOutOfBoundsException if the off and/or len are wrong.
+     */
+    public int inflate(byte[] buf, int off, int len) throws DataFormatException {
+        /* Special case: len may be zero */
+        if (len == 0)
+            return 0;
+        /* Check for correct buff, off, len triple */
+        if (0 > off || off > off + len || off + len > buf.length)
+            throw new ArrayIndexOutOfBoundsException();
+        int count = 0;
+        int more;
+        do {
+            if (mode != DECODE_CHKSUM) {
+                /* Don't give away any output, if we are waiting for the
+                 * checksum in the input stream.
+                 *
+                 * With this trick we have always:
+                 *   needsInput() and not finished()
+                 *   implies more output can be produced.
+                 */
+                more = outputWindow.copyOutput(buf, off, len);
+                adler.update(buf, off, more);
+                off += more;
+                count += more;
+                totalOut += more;
+                len -= more;
+                if (len == 0)
+                    return count;
+            }
+        }
+        while (decode() || (outputWindow.getAvailable() > 0
+                && mode != DECODE_CHKSUM));
+        return count;
+    }
+
+    /**
+     * Returns true, if a preset dictionary is needed to inflate the input.
+     */
+    public boolean needsDictionary() {
+        return mode == DECODE_DICT && neededBits == 0;
+    }
+
+    /**
+     * Returns true, if the input buffer is empty.
+     * You should then call setInput(). <br>
+     *
+     * <em>NOTE</em>: This method also returns true when the stream is finished.
+     */
+    public boolean needsInput() {
+        return input.needsInput();
+    }
+
+    /**
+     * Resets the inflater so that a new stream can be decompressed.  All
+     * pending input and output will be discarded.
+     */
+    public void reset() {
+        mode = nowrap ? DECODE_BLOCKS : DECODE_HEADER;
+        totalIn = totalOut = 0;
+        input.reset();
+        outputWindow.reset();
+        dynHeader = null;
+        litlenTree = null;
+        distTree = null;
+        isLastBlock = false;
+        adler.reset();
+    }
+
+    /**
+     * Sets the preset dictionary.  This should only be called, if
+     * needsDictionary() returns true and it should set the same
+     * dictionary, that was used for deflating.  The getAdler()
+     * function returns the checksum of the dictionary needed.
+     *
+     * @param buffer the dictionary.
+     * @throws IllegalStateException    if no dictionary is needed.
+     * @throws IllegalArgumentException if the dictionary checksum is
+     *                                  wrong.
+     */
+    public void setDictionary(byte[] buffer) {
+        setDictionary(buffer, 0, buffer.length);
+    }
+
+    /**
+     * Sets the preset dictionary.  This should only be called, if
+     * needsDictionary() returns true and it should set the same
+     * dictionary, that was used for deflating.  The getAdler()
+     * function returns the checksum of the dictionary needed.
+     *
+     * @param buffer the dictionary.
+     * @param off    the offset into buffer where the dictionary starts.
+     * @param len    the length of the dictionary.
+     * @throws IllegalStateException     if no dictionary is needed.
+     * @throws IllegalArgumentException  if the dictionary checksum is
+     *                                   wrong.
+     * @throws IndexOutOfBoundsException if the off and/or len are wrong.
+     */
+    public void setDictionary(byte[] buffer, int off, int len) {
+        if (!needsDictionary())
+            throw new IllegalStateException();
+
+        adler.update(buffer, off, len);
+        if ((int) adler.getValue() != readAdler)
+            throw new IllegalArgumentException("Wrong adler checksum");
+        adler.reset();
+        outputWindow.copyDict(buffer, off, len);
+        mode = DECODE_BLOCKS;
+    }
+
+    /**
+     * Sets the input.  This should only be called, if needsInput()
+     * returns true.
+     *
+     * @param buffer the input.
+     * @throws IllegalStateException if no input is needed.
+     */
+    public void setInput(byte[] buf) {
+        setInput(buf, 0, buf.length);
+    }
+
+    /**
+     * Sets the input.  This should only be called, if needsInput()
+     * returns true.
+     *
+     * @param buffer the input.
+     * @param off    the offset into buffer where the input starts.
+     * @param len    the length of the input.
+     * @throws IllegalStateException     if no input is needed.
+     * @throws IndexOutOfBoundsException if the off and/or len are wrong.
+     */
+    public void setInput(byte[] buf, int off, int len) {
+        input.setInput(buf, off, len);
+        totalIn += len;
+    }
+
+    /**
+     * Decodes the deflate header.
+     *
+     * @return false if more input is needed.
+     * @throws DataFormatException if header is invalid.
+     */
+    private boolean decodeHeader() throws DataFormatException {
+        int header = input.peekBits(16);
+        if (header < 0)
+            return false;
+        input.dropBits(16);
+
+        /* The header is written in "wrong" byte order */
+        header = ((header << 8) | (header >> 8)) & 0xffff;
+        if (header % 31 != 0)
+            throw new DataFormatException("Header checksum illegal");
+
+        if ((header & 0x0f00) != (Deflater.DEFLATED << 8))
+            throw new DataFormatException("Compression Method unknown");
+
+    /* Maximum size of the backwards window in bits. 
+     * We currently ignore this, but we could use it to make the
+     * inflater window more space efficient. On the other hand the
+     * full window (15 bits) is needed most times, anyway.
+     int max_wbits = ((header & 0x7000) >> 12) + 8;
+     */
+
+        if ((header & 0x0020) == 0) // Dictionary flag?
+        {
+            mode = DECODE_BLOCKS;
+        } else {
+            mode = DECODE_DICT;
+            neededBits = 32;
+        }
+        return true;
+    }
+
+    /**
+     * Decodes the dictionary checksum after the deflate header.
+     *
+     * @return false if more input is needed.
+     */
+    private boolean decodeDict() {
+        while (neededBits > 0) {
+            int dictByte = input.peekBits(8);
+            if (dictByte < 0)
+                return false;
+            input.dropBits(8);
+            readAdler = (readAdler << 8) | dictByte;
+            neededBits -= 8;
+        }
+        return false;
+    }
+
+    /**
+     * Decodes the huffman encoded symbols in the input stream.
+     *
+     * @return false if more input is needed, true if output window is
+     * full or the current block ends.
+     * @throws DataFormatException if deflated stream is invalid.
+     */
+    private boolean decodeHuffman() throws DataFormatException {
+        int free = outputWindow.getFreeSpace();
+        while (free >= 258) {
+            int symbol;
+            switch (mode) {
+                case DECODE_HUFFMAN:
+                    /* This is the inner loop so it is optimized a bit */
+                    while (((symbol = litlenTree.getSymbol(input)) & ~0xff) == 0) {
+                        outputWindow.write(symbol);
+                        if (--free < 258)
+                            return true;
+                    }
+                    if (symbol < 257) {
+                        if (symbol < 0)
+                            return false;
+                        else {
+                            /* symbol == 256: end of block */
+                            distTree = null;
+                            litlenTree = null;
+                            mode = DECODE_BLOCKS;
+                            return true;
+                        }
+                    }
+
+                    try {
+                        repLength = CPLENS[symbol - 257];
+                        neededBits = CPLEXT[symbol - 257];
+                    } catch (ArrayIndexOutOfBoundsException ex) {
+                        throw new DataFormatException("Illegal rep length code");
+                    }
+                    /* fall through */
+                case DECODE_HUFFMAN_LENBITS:
+                    if (neededBits > 0) {
+                        mode = DECODE_HUFFMAN_LENBITS;
+                        int i = input.peekBits(neededBits);
+                        if (i < 0)
+                            return false;
+                        input.dropBits(neededBits);
+                        repLength += i;
+                    }
+                    mode = DECODE_HUFFMAN_DIST;
+                    /* fall through */
+                case DECODE_HUFFMAN_DIST:
+                    symbol = distTree.getSymbol(input);
+                    if (symbol < 0)
+                        return false;
+                    try {
+                        repDist = CPDIST[symbol];
+                        neededBits = CPDEXT[symbol];
+                    } catch (ArrayIndexOutOfBoundsException ex) {
+                        throw new DataFormatException("Illegal rep dist code");
+                    }
+                    /* fall through */
+                case DECODE_HUFFMAN_DISTBITS:
+                    if (neededBits > 0) {
+                        mode = DECODE_HUFFMAN_DISTBITS;
+                        int i = input.peekBits(neededBits);
+                        if (i < 0)
+                            return false;
+                        input.dropBits(neededBits);
+                        repDist += i;
+                    }
+                    outputWindow.repeat(repLength, repDist);
+                    free -= repLength;
+                    mode = DECODE_HUFFMAN;
+                    break;
+                default:
+                    throw new IllegalStateException();
+            }
+        }
+        return true;
+    }
+
+    /**
+     * Decodes the adler checksum after the deflate stream.
+     *
+     * @return false if more input is needed.
+     * @throws DataFormatException if checksum doesn't match.
+     */
+    private boolean decodeChksum() throws DataFormatException {
+        while (neededBits > 0) {
+            int chkByte = input.peekBits(8);
+            if (chkByte < 0)
+                return false;
+            input.dropBits(8);
+            readAdler = (readAdler << 8) | chkByte;
+            neededBits -= 8;
+        }
+        if ((int) adler.getValue() != readAdler)
+            throw new DataFormatException("Adler chksum doesn't match: "
+                    + Integer.toHexString((int) adler.getValue())
+                    + " vs. " + Integer.toHexString(readAdler));
+        mode = FINISHED;
+        return false;
+    }
+
+    /**
+     * Decodes the deflated stream.
+     *
+     * @return false if more input is needed, or if finished.
+     * @throws DataFormatException if deflated stream is invalid.
+     */
+    private boolean decode() throws DataFormatException {
+        switch (mode) {
+            case DECODE_HEADER:
+                return decodeHeader();
+            case DECODE_DICT:
+                return decodeDict();
+            case DECODE_CHKSUM:
+                return decodeChksum();
+
+            case DECODE_BLOCKS:
+                if (isLastBlock) {
+                    if (nowrap) {
+                        mode = FINISHED;
+                        return false;
+                    } else {
+                        input.skipToByteBoundary();
+                        neededBits = 32;
+                        mode = DECODE_CHKSUM;
+                        return true;
+                    }
+                }
+
+                int type = input.peekBits(3);
+                if (type < 0)
+                    return false;
+                input.dropBits(3);
+
+                if ((type & 1) != 0)
+                    isLastBlock = true;
+                switch (type >> 1) {
+                    case DeflaterConstants.STORED_BLOCK:
+                        input.skipToByteBoundary();
+                        mode = DECODE_STORED_LEN1;
+                        break;
+                    case DeflaterConstants.STATIC_TREES:
+                        litlenTree = InflaterHuffmanTree.defLitLenTree;
+                        distTree = InflaterHuffmanTree.defDistTree;
+                        mode = DECODE_HUFFMAN;
+                        break;
+                    case DeflaterConstants.DYN_TREES:
+                        dynHeader = new InflaterDynHeader();
+                        mode = DECODE_DYN_HEADER;
+                        break;
+                    default:
+                        throw new DataFormatException("Unknown block type " + type);
+                }
+                return true;
+
+            case DECODE_STORED_LEN1: {
+                if ((uncomprLen = input.peekBits(16)) < 0)
+                    return false;
+                input.dropBits(16);
+                mode = DECODE_STORED_LEN2;
+            }
+            /* fall through */
+            case DECODE_STORED_LEN2: {
+                int nlen = input.peekBits(16);
+                if (nlen < 0)
+                    return false;
+                input.dropBits(16);
+                if (nlen != (uncomprLen ^ 0xffff))
+                    throw new DataFormatException("broken uncompressed block");
+                mode = DECODE_STORED;
+            }
+            /* fall through */
+            case DECODE_STORED: {
+                int more = outputWindow.copyStored(input, uncomprLen);
+                uncomprLen -= more;
+                if (uncomprLen == 0) {
+                    mode = DECODE_BLOCKS;
+                    return true;
+                }
+                return !input.needsInput();
+            }
+
+            case DECODE_DYN_HEADER:
+                if (!dynHeader.decode(input))
+                    return false;
+                litlenTree = dynHeader.buildLitLenTree();
+                distTree = dynHeader.buildDistTree();
+                mode = DECODE_HUFFMAN;
+                /* fall through */
+            case DECODE_HUFFMAN:
+            case DECODE_HUFFMAN_LENBITS:
+            case DECODE_HUFFMAN_DIST:
+            case DECODE_HUFFMAN_DISTBITS:
+                return decodeHuffman();
+            case FINISHED:
+                return false;
+            default:
+                throw new IllegalStateException();
+        }
+    }
+}

epublib/src/main/java/me/ag2s/epublib/zip/InflaterDynHeader.java

@@ -0,0 +1,187 @@
+/* me.ag2s.epublib.zip.InflaterDynHeader
+   Copyright (C) 2001 Free Software Foundation, Inc.
+
+This file is part of GNU Classpath.
+
+GNU Classpath is free software; you can redistribute it and/or modify
+it under the terms of the GNU General Public License as published by
+the Free Software Foundation; either version 2, or (at your option)
+any later version.
+
+GNU Classpath is distributed in the hope that it will be useful, but
+WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+General Public License for more details.
+
+You should have received a copy of the GNU General Public License
+along with GNU Classpath; see the file COPYING.  If not, write to the
+Free Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
+02111-1307 USA.
+
+Linking this library statically or dynamically with other modules is
+making a combined work based on this library.  Thus, the terms and
+conditions of the GNU General Public License cover the whole
+combination.
+
+As a special exception, the copyright holders of this library give you
+permission to link this library with independent modules to produce an
+executable, regardless of the license terms of these independent
+modules, and to copy and distribute the resulting executable under
+terms of your choice, provided that you also meet, for each linked
+independent module, the terms and conditions of the license of that
+module.  An independent module is a module which is not derived from
+or based on this library.  If you modify this library, you may extend
+this exception to your version of the library, but you are not
+obligated to do so.  If you do not wish to do so, delete this
+exception statement from your version. */
+
+package me.ag2s.epublib.zip;
+
+class InflaterDynHeader {
+    private static final int LNUM = 0;
+    private static final int DNUM = 1;
+    private static final int BLNUM = 2;
+    private static final int BLLENS = 3;
+    private static final int LENS = 4;
+    private static final int REPS = 5;
+
+    private static final int repMin[] = {3, 3, 11};
+    private static final int repBits[] = {2, 3, 7};
+
+
+    private byte[] blLens;
+    private byte[] litdistLens;
+
+    private InflaterHuffmanTree blTree;
+
+    private int mode;
+    private int lnum, dnum, blnum, num;
+    private int repSymbol;
+    private byte lastLen;
+    private int ptr;
+
+    private static final int[] BL_ORDER =
+            {16, 17, 18, 0, 8, 7, 9, 6, 10, 5, 11, 4, 12, 3, 13, 2, 14, 1, 15};
+
+    public InflaterDynHeader() {
+    }
+
+    public boolean decode(StreamManipulator input) throws DataFormatException {
+        decode_loop:
+        for (; ; ) {
+            switch (mode) {
+                case LNUM:
+                    lnum = input.peekBits(5);
+                    if (lnum < 0)
+                        return false;
+                    lnum += 257;
+                    input.dropBits(5);
+//  	    System.err.println("LNUM: "+lnum);
+                    mode = DNUM;
+                    /* fall through */
+                case DNUM:
+                    dnum = input.peekBits(5);
+                    if (dnum < 0)
+                        return false;
+                    dnum++;
+                    input.dropBits(5);
+//  	    System.err.println("DNUM: "+dnum);
+                    num = lnum + dnum;
+                    litdistLens = new byte[num];
+                    mode = BLNUM;
+                    /* fall through */
+                case BLNUM:
+                    blnum = input.peekBits(4);
+                    if (blnum < 0)
+                        return false;
+                    blnum += 4;
+                    input.dropBits(4);
+                    blLens = new byte[19];
+                    ptr = 0;
+//  	    System.err.println("BLNUM: "+blnum);
+                    mode = BLLENS;
+                    /* fall through */
+                case BLLENS:
+                    while (ptr < blnum) {
+                        int len = input.peekBits(3);
+                        if (len < 0)
+                            return false;
+                        input.dropBits(3);
+//  		System.err.println("blLens["+BL_ORDER[ptr]+"]: "+len);
+                        blLens[BL_ORDER[ptr]] = (byte) len;
+                        ptr++;
+                    }
+                    blTree = new InflaterHuffmanTree(blLens);
+                    blLens = null;
+                    ptr = 0;
+                    mode = LENS;
+                    /* fall through */
+                case LENS: {
+                    int symbol;
+                    while (((symbol = blTree.getSymbol(input)) & ~15) == 0) {
+                        /* Normal case: symbol in [0..15] */
+
+//  		  System.err.println("litdistLens["+ptr+"]: "+symbol);
+                        litdistLens[ptr++] = lastLen = (byte) symbol;
+
+                        if (ptr == num) {
+                            /* Finished */
+                            return true;
+                        }
+                    }
+
+                    /* need more input ? */
+                    if (symbol < 0)
+                        return false;
+
+                    /* otherwise repeat code */
+                    if (symbol >= 17) {
+                        /* repeat zero */
+//  		  System.err.println("repeating zero");
+                        lastLen = 0;
+                    } else {
+                        if (ptr == 0)
+                            throw new DataFormatException();
+                    }
+                    repSymbol = symbol - 16;
+                    mode = REPS;
+                }
+                /* fall through */
+
+                case REPS: {
+                    int bits = repBits[repSymbol];
+                    int count = input.peekBits(bits);
+                    if (count < 0)
+                        return false;
+                    input.dropBits(bits);
+                    count += repMin[repSymbol];
+//  	      System.err.println("litdistLens repeated: "+count);
+
+                    if (ptr + count > num)
+                        throw new DataFormatException();
+                    while (count-- > 0)
+                        litdistLens[ptr++] = lastLen;
+
+                    if (ptr == num) {
+                        /* Finished */
+                        return true;
+                    }
+                }
+                mode = LENS;
+                continue decode_loop;
+            }
+        }
+    }
+
+    public InflaterHuffmanTree buildLitLenTree() throws DataFormatException {
+        byte[] litlenLens = new byte[lnum];
+        System.arraycopy(litdistLens, 0, litlenLens, 0, lnum);
+        return new InflaterHuffmanTree(litlenLens);
+    }
+
+    public InflaterHuffmanTree buildDistTree() throws DataFormatException {
+        byte[] distLens = new byte[dnum];
+        System.arraycopy(litdistLens, lnum, distLens, 0, dnum);
+        return new InflaterHuffmanTree(distLens);
+    }
+}

epublib/src/main/java/me/ag2s/epublib/zip/InflaterHuffmanTree.java

@@ -0,0 +1,187 @@
+/* me.ag2s.epublib.zip.InflaterHuffmanTree
+   Copyright (C) 2001 Free Software Foundation, Inc.
+
+This file is part of GNU Classpath.
+
+GNU Classpath is free software; you can redistribute it and/or modify
+it under the terms of the GNU General Public License as published by
+the Free Software Foundation; either version 2, or (at your option)
+any later version.
+
+GNU Classpath is distributed in the hope that it will be useful, but
+WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+General Public License for more details.
+
+You should have received a copy of the GNU General Public License
+along with GNU Classpath; see the file COPYING.  If not, write to the
+Free Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
+02111-1307 USA.
+
+Linking this library statically or dynamically with other modules is
+making a combined work based on this library.  Thus, the terms and
+conditions of the GNU General Public License cover the whole
+combination.
+
+As a special exception, the copyright holders of this library give you
+permission to link this library with independent modules to produce an
+executable, regardless of the license terms of these independent
+modules, and to copy and distribute the resulting executable under
+terms of your choice, provided that you also meet, for each linked
+independent module, the terms and conditions of the license of that
+module.  An independent module is a module which is not derived from
+or based on this library.  If you modify this library, you may extend
+this exception to your version of the library, but you are not
+obligated to do so.  If you do not wish to do so, delete this
+exception statement from your version. */
+
+package me.ag2s.epublib.zip;
+
+public class InflaterHuffmanTree {
+    private final static int MAX_BITLEN = 15;
+    private short[] tree;
+
+    public static InflaterHuffmanTree defLitLenTree, defDistTree;
+
+    static {
+        try {
+            byte[] codeLengths = new byte[288];
+            int i = 0;
+            while (i < 144)
+                codeLengths[i++] = 8;
+            while (i < 256)
+                codeLengths[i++] = 9;
+            while (i < 280)
+                codeLengths[i++] = 7;
+            while (i < 288)
+                codeLengths[i++] = 8;
+            defLitLenTree = new InflaterHuffmanTree(codeLengths);
+
+            codeLengths = new byte[32];
+            i = 0;
+            while (i < 32)
+                codeLengths[i++] = 5;
+            defDistTree = new InflaterHuffmanTree(codeLengths);
+        } catch (DataFormatException ex) {
+            throw new InternalError
+                    ("InflaterHuffmanTree: static tree length illegal");
+        }
+    }
+
+    /**
+     * Constructs a Huffman tree from the array of code lengths.
+     *
+     * @param codeLengths the array of code lengths
+     */
+    public InflaterHuffmanTree(byte[] codeLengths) throws DataFormatException {
+        buildTree(codeLengths);
+    }
+
+    private void buildTree(byte[] codeLengths) throws DataFormatException {
+        int[] blCount = new int[MAX_BITLEN + 1];
+        int[] nextCode = new int[MAX_BITLEN + 1];
+        for (int i = 0; i < codeLengths.length; i++) {
+            int bits = codeLengths[i];
+            if (bits > 0)
+                blCount[bits]++;
+        }
+
+        int code = 0;
+        int treeSize = 512;
+        for (int bits = 1; bits <= MAX_BITLEN; bits++) {
+            nextCode[bits] = code;
+            code += blCount[bits] << (16 - bits);
+            if (bits >= 10) {
+                /* We need an extra table for bit lengths >= 10. */
+                int start = nextCode[bits] & 0x1ff80;
+                int end = code & 0x1ff80;
+                treeSize += (end - start) >> (16 - bits);
+            }
+        }
+        if (code != 65536)
+            throw new DataFormatException("Code lengths don't add up properly.");
+
+        /* Now create and fill the extra tables from longest to shortest
+         * bit len.  This way the sub trees will be aligned.
+         */
+        tree = new short[treeSize];
+        int treePtr = 512;
+        for (int bits = MAX_BITLEN; bits >= 10; bits--) {
+            int end = code & 0x1ff80;
+            code -= blCount[bits] << (16 - bits);
+            int start = code & 0x1ff80;
+            for (int i = start; i < end; i += 1 << 7) {
+                tree[DeflaterHuffman.bitReverse(i)]
+                        = (short) ((-treePtr << 4) | bits);
+                treePtr += 1 << (bits - 9);
+            }
+        }
+
+        for (int i = 0; i < codeLengths.length; i++) {
+            int bits = codeLengths[i];
+            if (bits == 0)
+                continue;
+            code = nextCode[bits];
+            int revcode = DeflaterHuffman.bitReverse(code);
+            if (bits <= 9) {
+                do {
+                    tree[revcode] = (short) ((i << 4) | bits);
+                    revcode += 1 << bits;
+                }
+                while (revcode < 512);
+            } else {
+                int subTree = tree[revcode & 511];
+                int treeLen = 1 << (subTree & 15);
+                subTree = -(subTree >> 4);
+                do {
+                    tree[subTree | (revcode >> 9)] = (short) ((i << 4) | bits);
+                    revcode += 1 << bits;
+                }
+                while (revcode < treeLen);
+            }
+            nextCode[bits] = code + (1 << (16 - bits));
+        }
+    }
+
+    /**
+     * Reads the next symbol from input.  The symbol is encoded using the
+     * huffman tree.
+     *
+     * @param input the input source.
+     * @return the next symbol, or -1 if not enough input is available.
+     */
+    public int getSymbol(StreamManipulator input) throws DataFormatException {
+        int lookahead, symbol;
+        if ((lookahead = input.peekBits(9)) >= 0) {
+            if ((symbol = tree[lookahead]) >= 0) {
+                input.dropBits(symbol & 15);
+                return symbol >> 4;
+            }
+            int subtree = -(symbol >> 4);
+            int bitlen = symbol & 15;
+            if ((lookahead = input.peekBits(bitlen)) >= 0) {
+                symbol = tree[subtree | (lookahead >> 9)];
+                input.dropBits(symbol & 15);
+                return symbol >> 4;
+            } else {
+                int bits = input.getAvailableBits();
+                lookahead = input.peekBits(bits);
+                symbol = tree[subtree | (lookahead >> 9)];
+                if ((symbol & 15) <= bits) {
+                    input.dropBits(symbol & 15);
+                    return symbol >> 4;
+                } else
+                    return -1;
+            }
+        } else {
+            int bits = input.getAvailableBits();
+            lookahead = input.peekBits(bits);
+            symbol = tree[lookahead];
+            if (symbol >= 0 && (symbol & 15) <= bits) {
+                input.dropBits(symbol & 15);
+                return symbol >> 4;
+            } else
+                return -1;
+        }
+    }
+}

epublib/src/main/java/me/ag2s/epublib/zip/InflaterInputStream.java

@@ -0,0 +1,230 @@
+/* InflaterInputStream.java - Input stream filter for decompressing
+   Copyright (C) 1999, 2000, 2001, 2002, 2003, 2004
+   Free Software Foundation, Inc.
+
+This file is part of GNU Classpath.
+
+GNU Classpath is free software; you can redistribute it and/or modify
+it under the terms of the GNU General Public License as published by
+the Free Software Foundation; either version 2, or (at your option)
+any later version.
+ 
+GNU Classpath is distributed in the hope that it will be useful, but
+WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+General Public License for more details.
+
+You should have received a copy of the GNU General Public License
+along with GNU Classpath; see the file COPYING.  If not, write to the
+Free Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
+02111-1307 USA.
+
+Linking this library statically or dynamically with other modules is
+making a combined work based on this library.  Thus, the terms and
+conditions of the GNU General Public License cover the whole
+combination.
+
+As a special exception, the copyright holders of this library give you
+permission to link this library with independent modules to produce an
+executable, regardless of the license terms of these independent
+modules, and to copy and distribute the resulting executable under
+terms of your choice, provided that you also meet, for each linked
+independent module, the terms and conditions of the license of that
+module.  An independent module is a module which is not derived from
+or based on this library.  If you modify this library, you may extend
+this exception to your version of the library, but you are not
+obligated to do so.  If you do not wish to do so, delete this
+exception statement from your version. */
+
+package me.ag2s.epublib.zip;
+
+import java.io.FilterInputStream;
+import java.io.IOException;
+import java.io.InputStream;
+
+/**
+ * This filter stream is used to decompress data compressed in the "deflate"
+ * format. The "deflate" format is described in RFC 1951.
+ * <p>
+ * This stream may form the basis for other decompression filters, such
+ * as the <code>GZIPInputStream</code>.
+ *
+ * @author John Leuner
+ * @author Tom Tromey
+ * @since 1.1
+ */
+public class InflaterInputStream extends FilterInputStream {
+    /**
+     * Decompressor for this filter
+     */
+    protected Inflater inf;
+
+    /**
+     * Byte array used as a buffer
+     */
+    protected byte[] buf;
+
+    /**
+     * Size of buffer
+     */
+    protected int len;
+
+    /*
+     * We just use this if we are decoding one byte at a time with the read() call
+     */
+    private byte[] onebytebuffer = new byte[1];
+
+    /**
+     * Create an InflaterInputStream with the default decompresseor
+     * and a default buffer size.
+     *
+     * @param in the InputStream to read bytes from
+     */
+    public InflaterInputStream(InputStream in) {
+        this(in, new Inflater(), 4096);
+    }
+
+    /**
+     * Create an InflaterInputStream with the specified decompresseor
+     * and a default buffer size.
+     *
+     * @param in  the InputStream to read bytes from
+     * @param inf the decompressor used to decompress data read from in
+     */
+    public InflaterInputStream(InputStream in, Inflater inf) {
+        this(in, inf, 4096);
+    }
+
+    /**
+     * Create an InflaterInputStream with the specified decompresseor
+     * and a specified buffer size.
+     *
+     * @param in   the InputStream to read bytes from
+     * @param inf  the decompressor used to decompress data read from in
+     * @param size size of the buffer to use
+     */
+    public InflaterInputStream(InputStream in, Inflater inf, int size) {
+        super(in);
+        this.len = 0;
+
+        if (in == null)
+            throw new NullPointerException("in may not be null");
+        if (inf == null)
+            throw new NullPointerException("inf may not be null");
+        if (size < 0)
+            throw new IllegalArgumentException("size may not be negative");
+
+        this.inf = inf;
+        this.buf = new byte[size];
+    }
+
+    /**
+     * Returns 0 once the end of the stream (EOF) has been reached.
+     * Otherwise returns 1.
+     */
+    public int available() throws IOException {
+        // According to the JDK 1.2 docs, this should only ever return 0
+        // or 1 and should not be relied upon by Java programs.
+        return inf.finished() ? 0 : 1;
+    }
+
+    /**
+     * Closes the input stream
+     */
+    public synchronized void close() throws IOException {
+        if (in != null)
+            in.close();
+        in = null;
+    }
+
+    /**
+     * Fills the buffer with more data to decompress.
+     */
+    protected void fill() throws IOException {
+        if (in == null)
+            throw new ZipException("InflaterInputStream is closed");
+
+        len = in.read(buf, 0, buf.length);
+
+        if (len < 0)
+            throw new ZipException("Deflated stream ends early.");
+
+        inf.setInput(buf, 0, len);
+    }
+
+    /**
+     * Reads one byte of decompressed data.
+     * <p>
+     * The byte is in the lower 8 bits of the int.
+     */
+    public int read() throws IOException {
+        int nread = read(onebytebuffer, 0, 1); //read one byte
+
+        if (nread > 0)
+            return onebytebuffer[0] & 0xff;
+
+        return -1;
+    }
+
+    /**
+     * Decompresses data into the byte array
+     *
+     * @param b   the array to read and decompress data into
+     * @param off the offset indicating where the data should be placed
+     * @param len the number of bytes to decompress
+     */
+    public int read(byte[] b, int off, int len) throws IOException {
+        if (len == 0)
+            return 0;
+
+        for (; ; ) {
+            int count;
+
+            try {
+                count = inf.inflate(b, off, len);
+            } catch (DataFormatException dfe) {
+                throw new ZipException(dfe.getMessage());
+            }
+
+            if (count > 0)
+                return count;
+
+            if (inf.needsDictionary()
+                    | inf.finished())
+                return -1;
+            else if (inf.needsInput())
+                fill();
+            else
+                throw new InternalError("Don't know what to do");
+        }
+    }
+
+    /**
+     * Skip specified number of bytes of uncompressed data
+     *
+     * @param n number of bytes to skip
+     */
+    public long skip(long n) throws IOException {
+        if (n < 0)
+            throw new IllegalArgumentException();
+
+        if (n == 0)
+            return 0;
+
+        // Implementation copied from InputStream
+        // Throw away n bytes by reading them into a temp byte[].
+        // Limit the temp array to 2Kb so we don't grab too much memory.
+        final int buflen = n > 2048 ? 2048 : (int) n;
+        byte[] tmpbuf = new byte[buflen];
+        final long origN = n;
+
+        while (n > 0L) {
+            int numread = read(tmpbuf, 0, n > buflen ? buflen : (int) n);
+            if (numread <= 0)
+                break;
+            n -= numread;
+        }
+
+        return origN - n;
+    }
+}

epublib/src/main/java/me/ag2s/epublib/zip/OutputWindow.java

@@ -0,0 +1,161 @@
+/* me.ag2s.epublib.zip.OutputWindow
+   Copyright (C) 2001 Free Software Foundation, Inc.
+
+This file is part of GNU Classpath.
+
+GNU Classpath is free software; you can redistribute it and/or modify
+it under the terms of the GNU General Public License as published by
+the Free Software Foundation; either version 2, or (at your option)
+any later version.
+
+GNU Classpath is distributed in the hope that it will be useful, but
+WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+General Public License for more details.
+
+You should have received a copy of the GNU General Public License
+along with GNU Classpath; see the file COPYING.  If not, write to the
+Free Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
+02111-1307 USA.
+
+Linking this library statically or dynamically with other modules is
+making a combined work based on this library.  Thus, the terms and
+conditions of the GNU General Public License cover the whole
+combination.
+
+As a special exception, the copyright holders of this library give you
+permission to link this library with independent modules to produce an
+executable, regardless of the license terms of these independent
+modules, and to copy and distribute the resulting executable under
+terms of your choice, provided that you also meet, for each linked
+independent module, the terms and conditions of the license of that
+module.  An independent module is a module which is not derived from
+or based on this library.  If you modify this library, you may extend
+this exception to your version of the library, but you are not
+obligated to do so.  If you do not wish to do so, delete this
+exception statement from your version. */
+
+package me.ag2s.epublib.zip;
+
+/*
+ * Contains the output from the Inflation process.
+ *
+ * We need to have a window so that we can refer backwards into the output stream
+ * to repeat stuff.
+ *
+ * @author John Leuner
+ * @since JDK 1.1
+ */
+
+class OutputWindow {
+    private final int WINDOW_SIZE = 1 << 15;
+    private final int WINDOW_MASK = WINDOW_SIZE - 1;
+
+    private byte[] window = new byte[WINDOW_SIZE]; //The window is 2^15 bytes
+    private int window_end = 0;
+    private int window_filled = 0;
+
+    public void write(int abyte) {
+        if (window_filled++ == WINDOW_SIZE)
+            throw new IllegalStateException("Window full");
+        window[window_end++] = (byte) abyte;
+        window_end &= WINDOW_MASK;
+    }
+
+
+    private final void slowRepeat(int rep_start, int len, int dist) {
+        while (len-- > 0) {
+            window[window_end++] = window[rep_start++];
+            window_end &= WINDOW_MASK;
+            rep_start &= WINDOW_MASK;
+        }
+    }
+
+    public void repeat(int len, int dist) {
+        if ((window_filled += len) > WINDOW_SIZE)
+            throw new IllegalStateException("Window full");
+
+        int rep_start = (window_end - dist) & WINDOW_MASK;
+        int border = WINDOW_SIZE - len;
+        if (rep_start <= border && window_end < border) {
+            if (len <= dist) {
+                System.arraycopy(window, rep_start, window, window_end, len);
+                window_end += len;
+            } else {
+                /* We have to copy manually, since the repeat pattern overlaps.
+                 */
+                while (len-- > 0)
+                    window[window_end++] = window[rep_start++];
+            }
+        } else
+            slowRepeat(rep_start, len, dist);
+    }
+
+    public int copyStored(StreamManipulator input, int len) {
+        len = Math.min(Math.min(len, WINDOW_SIZE - window_filled),
+                input.getAvailableBytes());
+        int copied;
+
+        int tailLen = WINDOW_SIZE - window_end;
+        if (len > tailLen) {
+            copied = input.copyBytes(window, window_end, tailLen);
+            if (copied == tailLen)
+                copied += input.copyBytes(window, 0, len - tailLen);
+        } else
+            copied = input.copyBytes(window, window_end, len);
+
+        window_end = (window_end + copied) & WINDOW_MASK;
+        window_filled += copied;
+        return copied;
+    }
+
+    public void copyDict(byte[] dict, int offset, int len) {
+        if (window_filled > 0)
+            throw new IllegalStateException();
+
+        if (len > WINDOW_SIZE) {
+            offset += len - WINDOW_SIZE;
+            len = WINDOW_SIZE;
+        }
+        System.arraycopy(dict, offset, window, 0, len);
+        window_end = len & WINDOW_MASK;
+    }
+
+    public int getFreeSpace() {
+        return WINDOW_SIZE - window_filled;
+    }
+
+    public int getAvailable() {
+        return window_filled;
+    }
+
+    public int copyOutput(byte[] output, int offset, int len) {
+        int copy_end = window_end;
+        if (len > window_filled)
+            len = window_filled;
+        else
+            copy_end = (window_end - window_filled + len) & WINDOW_MASK;
+
+        int copied = len;
+        int tailLen = len - copy_end;
+
+        if (tailLen > 0) {
+            System.arraycopy(window, WINDOW_SIZE - tailLen,
+                    output, offset, tailLen);
+            offset += tailLen;
+            len = copy_end;
+        }
+        System.arraycopy(window, copy_end - len, output, offset, len);
+        window_filled -= copied;
+        if (window_filled < 0)
+            throw new IllegalStateException();
+        return copied;
+    }
+
+    public void reset() {
+        window_filled = window_end = 0;
+    }
+}
+
+
+

epublib/src/main/java/me/ag2s/epublib/zip/PendingBuffer.java

@@ -0,0 +1,181 @@
+/* me.ag2s.epublib.zip.PendingBuffer
+   Copyright (C) 2001 Free Software Foundation, Inc.
+
+This file is part of GNU Classpath.
+
+GNU Classpath is free software; you can redistribute it and/or modify
+it under the terms of the GNU General Public License as published by
+the Free Software Foundation; either version 2, or (at your option)
+any later version.
+
+GNU Classpath is distributed in the hope that it will be useful, but
+WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+General Public License for more details.
+
+You should have received a copy of the GNU General Public License
+along with GNU Classpath; see the file COPYING.  If not, write to the
+Free Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
+02111-1307 USA.
+
+Linking this library statically or dynamically with other modules is
+making a combined work based on this library.  Thus, the terms and
+conditions of the GNU General Public License cover the whole
+combination.
+
+As a special exception, the copyright holders of this library give you
+permission to link this library with independent modules to produce an
+executable, regardless of the license terms of these independent
+modules, and to copy and distribute the resulting executable under
+terms of your choice, provided that you also meet, for each linked
+independent module, the terms and conditions of the license of that
+module.  An independent module is a module which is not derived from
+or based on this library.  If you modify this library, you may extend
+this exception to your version of the library, but you are not
+obligated to do so.  If you do not wish to do so, delete this
+exception statement from your version. */
+
+package me.ag2s.epublib.zip;
+
+/**
+ * This class is general purpose class for writing data to a buffer.
+ * <p>
+ * It allows you to write bits as well as bytes
+ * <p>
+ * Based on DeflaterPending.java
+ *
+ * @author Jochen Hoenicke
+ * @date Jan 5, 2000
+ */
+
+class PendingBuffer {
+    protected byte[] buf;
+    int start;
+    int end;
+
+    int bits;
+    int bitCount;
+
+    public PendingBuffer() {
+        this(4096);
+    }
+
+    public PendingBuffer(int bufsize) {
+        buf = new byte[bufsize];
+    }
+
+    public final void reset() {
+        start = end = bitCount = 0;
+    }
+
+    public final void writeByte(int b) {
+        if (DeflaterConstants.DEBUGGING && start != 0)
+            throw new IllegalStateException();
+        buf[end++] = (byte) b;
+    }
+
+    public final void writeShort(int s) {
+        if (DeflaterConstants.DEBUGGING && start != 0)
+            throw new IllegalStateException();
+        buf[end++] = (byte) s;
+        buf[end++] = (byte) (s >> 8);
+    }
+
+    public final void writeInt(int s) {
+        if (DeflaterConstants.DEBUGGING && start != 0)
+            throw new IllegalStateException();
+        buf[end++] = (byte) s;
+        buf[end++] = (byte) (s >> 8);
+        buf[end++] = (byte) (s >> 16);
+        buf[end++] = (byte) (s >> 24);
+    }
+
+    public final void writeBlock(byte[] block, int offset, int len) {
+        if (DeflaterConstants.DEBUGGING && start != 0)
+            throw new IllegalStateException();
+        System.arraycopy(block, offset, buf, end, len);
+        end += len;
+    }
+
+    public final int getBitCount() {
+        return bitCount;
+    }
+
+    public final void alignToByte() {
+        if (DeflaterConstants.DEBUGGING && start != 0)
+            throw new IllegalStateException();
+        if (bitCount > 0) {
+            buf[end++] = (byte) bits;
+            if (bitCount > 8)
+                buf[end++] = (byte) (bits >>> 8);
+        }
+        bits = 0;
+        bitCount = 0;
+    }
+
+    public final void writeBits(int b, int count) {
+        if (DeflaterConstants.DEBUGGING && start != 0)
+            throw new IllegalStateException();
+        if (DeflaterConstants.DEBUGGING)
+            System.err.println("writeBits(" + Integer.toHexString(b) + "," + count + ")");
+        bits |= b << bitCount;
+        bitCount += count;
+        if (bitCount >= 16) {
+            buf[end++] = (byte) bits;
+            buf[end++] = (byte) (bits >>> 8);
+            bits >>>= 16;
+            bitCount -= 16;
+        }
+    }
+
+    public final void writeShortMSB(int s) {
+        if (DeflaterConstants.DEBUGGING && start != 0)
+            throw new IllegalStateException();
+        buf[end++] = (byte) (s >> 8);
+        buf[end++] = (byte) s;
+    }
+
+    public final boolean isFlushed() {
+        return end == 0;
+    }
+
+    /**
+     * Flushes the pending buffer into the given output array.  If the
+     * output array is to small, only a partial flush is done.
+     *
+     * @param output the output array;
+     * @param offset the offset into output array;
+     * @param length the maximum number of bytes to store;
+     * @throws IndexOutOfBoundsException if offset or length are
+     *                                   invalid.
+     */
+    public final int flush(byte[] output, int offset, int length) {
+        if (bitCount >= 8) {
+            buf[end++] = (byte) bits;
+            bits >>>= 8;
+            bitCount -= 8;
+        }
+        if (length > end - start) {
+            length = end - start;
+            System.arraycopy(buf, start, output, offset, length);
+            start = 0;
+            end = 0;
+        } else {
+            System.arraycopy(buf, start, output, offset, length);
+            start += length;
+        }
+        return length;
+    }
+
+
+    public final byte[] toByteArray() {
+        byte[] ret = new byte[end - start];
+        System.arraycopy(buf, start, ret, 0, ret.length);
+        start = 0;
+        end = 0;
+        return ret;
+    }
+
+
+}
+

epublib/src/main/java/me/ag2s/epublib/zip/StreamManipulator.java

@@ -0,0 +1,206 @@
+/* me.ag2s.epublib.zip.StreamManipulator
+   Copyright (C) 2001 Free Software Foundation, Inc.
+
+This file is part of GNU Classpath.
+
+GNU Classpath is free software; you can redistribute it and/or modify
+it under the terms of the GNU General Public License as published by
+the Free Software Foundation; either version 2, or (at your option)
+any later version.
+
+GNU Classpath is distributed in the hope that it will be useful, but
+WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+General Public License for more details.
+
+You should have received a copy of the GNU General Public License
+along with GNU Classpath; see the file COPYING.  If not, write to the
+Free Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
+02111-1307 USA.
+
+Linking this library statically or dynamically with other modules is
+making a combined work based on this library.  Thus, the terms and
+conditions of the GNU General Public License cover the whole
+combination.
+
+As a special exception, the copyright holders of this library give you
+permission to link this library with independent modules to produce an
+executable, regardless of the license terms of these independent
+modules, and to copy and distribute the resulting executable under
+terms of your choice, provided that you also meet, for each linked
+independent module, the terms and conditions of the license of that
+module.  An independent module is a module which is not derived from
+or based on this library.  If you modify this library, you may extend
+this exception to your version of the library, but you are not
+obligated to do so.  If you do not wish to do so, delete this
+exception statement from your version. */
+
+package me.ag2s.epublib.zip;
+
+/**
+ * This class allows us to retrieve a specified amount of bits from
+ * the input buffer, as well as copy big byte blocks.
+ * <p>
+ * It uses an int buffer to store up to 31 bits for direct
+ * manipulation.  This guarantees that we can get at least 16 bits,
+ * but we only need at most 15, so this is all safe.
+ * <p>
+ * There are some optimizations in this class, for example, you must
+ * never peek more then 8 bits more than needed, and you must first
+ * peek bits before you may drop them.  This is not a general purpose
+ * class but optimized for the behaviour of the Inflater.
+ *
+ * @author John Leuner, Jochen Hoenicke
+ */
+
+class StreamManipulator {
+    private byte[] window;
+    private int window_start = 0;
+    private int window_end = 0;
+
+    private int buffer = 0;
+    private int bits_in_buffer = 0;
+
+    /**
+     * Get the next n bits but don't increase input pointer.  n must be
+     * less or equal 16 and if you if this call succeeds, you must drop
+     * at least n-8 bits in the next call.
+     *
+     * @return the value of the bits, or -1 if not enough bits available.
+     */
+    public final int peekBits(int n) {
+        if (bits_in_buffer < n) {
+            if (window_start == window_end)
+                return -1;
+            buffer |= (window[window_start++] & 0xff
+                    | (window[window_start++] & 0xff) << 8) << bits_in_buffer;
+            bits_in_buffer += 16;
+        }
+        return buffer & ((1 << n) - 1);
+    }
+
+    /* Drops the next n bits from the input.  You should have called peekBits
+     * with a bigger or equal n before, to make sure that enough bits are in
+     * the bit buffer.
+     */
+    public final void dropBits(int n) {
+        buffer >>>= n;
+        bits_in_buffer -= n;
+    }
+
+    /**
+     * Gets the next n bits and increases input pointer.  This is equivalent
+     * to peekBits followed by dropBits, except for correct error handling.
+     *
+     * @return the value of the bits, or -1 if not enough bits available.
+     */
+    public final int getBits(int n) {
+        int bits = peekBits(n);
+        if (bits >= 0)
+            dropBits(n);
+        return bits;
+    }
+
+    /**
+     * Gets the number of bits available in the bit buffer.  This must be
+     * only called when a previous peekBits() returned -1.
+     *
+     * @return the number of bits available.
+     */
+    public final int getAvailableBits() {
+        return bits_in_buffer;
+    }
+
+    /**
+     * Gets the number of bytes available.
+     *
+     * @return the number of bytes available.
+     */
+    public final int getAvailableBytes() {
+        return window_end - window_start + (bits_in_buffer >> 3);
+    }
+
+    /**
+     * Skips to the next byte boundary.
+     */
+    public void skipToByteBoundary() {
+        buffer >>= (bits_in_buffer & 7);
+        bits_in_buffer &= ~7;
+    }
+
+    public final boolean needsInput() {
+        return window_start == window_end;
+    }
+
+
+    /* Copies length bytes from input buffer to output buffer starting
+     * at output[offset].  You have to make sure, that the buffer is
+     * byte aligned.  If not enough bytes are available, copies fewer
+     * bytes.
+     * @param length the length to copy, 0 is allowed.
+     * @return the number of bytes copied, 0 if no byte is available.
+     */
+    public int copyBytes(byte[] output, int offset, int length) {
+        if (length < 0)
+            throw new IllegalArgumentException("length negative");
+        if ((bits_in_buffer & 7) != 0)
+            /* bits_in_buffer may only be 0 or 8 */
+            throw new IllegalStateException("Bit buffer is not aligned!");
+
+        int count = 0;
+        while (bits_in_buffer > 0 && length > 0) {
+            output[offset++] = (byte) buffer;
+            buffer >>>= 8;
+            bits_in_buffer -= 8;
+            length--;
+            count++;
+        }
+        if (length == 0)
+            return count;
+
+        int avail = window_end - window_start;
+        if (length > avail)
+            length = avail;
+        System.arraycopy(window, window_start, output, offset, length);
+        window_start += length;
+
+        if (((window_start - window_end) & 1) != 0) {
+            /* We always want an even number of bytes in input, see peekBits */
+            buffer = (window[window_start++] & 0xff);
+            bits_in_buffer = 8;
+        }
+        return count + length;
+    }
+
+    public StreamManipulator() {
+    }
+
+    public void reset() {
+        window_start = window_end = buffer = bits_in_buffer = 0;
+    }
+
+    public void setInput(byte[] buf, int off, int len) {
+        if (window_start < window_end)
+            throw new IllegalStateException
+                    ("Old input was not completely processed");
+
+        int end = off + len;
+
+        /* We want to throw an ArrayIndexOutOfBoundsException early.  The
+         * check is very tricky: it also handles integer wrap around.
+         */
+        if (0 > off || off > end || end > buf.length)
+            throw new ArrayIndexOutOfBoundsException();
+
+        if ((len & 1) != 0) {
+            /* We always want an even number of bytes in input, see peekBits */
+            buffer |= (buf[off++] & 0xff) << bits_in_buffer;
+            bits_in_buffer += 8;
+        }
+
+        window = buf;
+        window_start = off;
+        window_end = end;
+    }
+}
+

epublib/src/main/java/me/ag2s/epublib/zip/ZipConstants.java

@@ -0,0 +1,96 @@
+/* me.ag2s.epublib.zip.ZipConstants
+   Copyright (C) 2001 Free Software Foundation, Inc.
+
+This file is part of GNU Classpath.
+
+GNU Classpath is free software; you can redistribute it and/or modify
+it under the terms of the GNU General Public License as published by
+the Free Software Foundation; either version 2, or (at your option)
+any later version.
+
+GNU Classpath is distributed in the hope that it will be useful, but
+WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+General Public License for more details.
+
+You should have received a copy of the GNU General Public License
+along with GNU Classpath; see the file COPYING.  If not, write to the
+Free Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
+02111-1307 USA.
+
+Linking this library statically or dynamically with other modules is
+making a combined work based on this library.  Thus, the terms and
+conditions of the GNU General Public License cover the whole
+combination.
+
+As a special exception, the copyright holders of this library give you
+permission to link this library with independent modules to produce an
+executable, regardless of the license terms of these independent
+modules, and to copy and distribute the resulting executable under
+terms of your choice, provided that you also meet, for each linked
+independent module, the terms and conditions of the license of thata
+module.  An independent module is a module which is not derived from
+or based on this library.  If you modify this library, you may extend
+this exception to your version of the library, but you are not
+obligated to do so.  If you do not wish to do so, delete this
+exception statement from your version. */
+
+package me.ag2s.epublib.zip;
+
+interface ZipConstants {
+    /* The local file header */
+    int LOCHDR = 30;
+    int LOCSIG = 'P' | ('K' << 8) | (3 << 16) | (4 << 24);
+
+    int LOCVER = 4;
+    int LOCFLG = 6;
+    int LOCHOW = 8;
+    int LOCTIM = 10;
+    int LOCCRC = 14;
+    int LOCSIZ = 18;
+    int LOCLEN = 22;
+    int LOCNAM = 26;
+    int LOCEXT = 28;
+
+    /* The Data descriptor */
+    int EXTSIG = 'P' | ('K' << 8) | (7 << 16) | (8 << 24);
+    int EXTHDR = 16;
+
+    int EXTCRC = 4;
+    int EXTSIZ = 8;
+    int EXTLEN = 12;
+
+    /* The central directory file header */
+    int CENSIG = 'P' | ('K' << 8) | (1 << 16) | (2 << 24);
+    int CENHDR = 46;
+
+    int CENVEM = 4;
+    int CENVER = 6;
+    int CENFLG = 8;
+    int CENHOW = 10;
+    int CENTIM = 12;
+    int CENCRC = 16;
+    int CENSIZ = 20;
+    int CENLEN = 24;
+    int CENNAM = 28;
+    int CENEXT = 30;
+    int CENCOM = 32;
+    int CENDSK = 34;
+    int CENATT = 36;
+    int CENATX = 38;
+    int CENOFF = 42;
+
+    /* The entries in the end of central directory */
+    int ENDSIG = 'P' | ('K' << 8) | (5 << 16) | (6 << 24);
+    int ENDHDR = 22;
+
+    /* The following two fields are missing in SUN JDK */
+    int ENDNRD = 4;
+    int ENDDCD = 6;
+    int ENDSUB = 8;
+    int ENDTOT = 10;
+    int ENDSIZ = 12;
+    int ENDOFF = 16;
+    int ENDCOM = 20;
+}
+

epublib/src/main/java/me/ag2s/epublib/zip/ZipEntry.java

@@ -0,0 +1,389 @@
+/* me.ag2s.epublib.zip.ZipEntry
+   Copyright (C) 2001, 2002 Free Software Foundation, Inc.
+
+This file is part of GNU Classpath.
+
+GNU Classpath is free software; you can redistribute it and/or modify
+it under the terms of the GNU General Public License as published by
+the Free Software Foundation; either version 2, or (at your option)
+any later version.
+
+GNU Classpath is distributed in the hope that it will be useful, but
+WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+General Public License for more details.
+
+You should have received a copy of the GNU General Public License
+along with GNU Classpath; see the file COPYING.  If not, write to the
+Free Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
+02111-1307 USA.
+
+Linking this library statically or dynamically with other modules is
+making a combined work based on this library.  Thus, the terms and
+conditions of the GNU General Public License cover the whole
+combination.
+
+As a special exception, the copyright holders of this library give you
+permission to link this library with independent modules to produce an
+executable, regardless of the license terms of these independent
+modules, and to copy and distribute the resulting executable under
+terms of your choice, provided that you also meet, for each linked
+independent module, the terms and conditions of the license of that
+module.  An independent module is a module which is not derived from
+or based on this library.  If you modify this library, you may extend
+this exception to your version of the library, but you are not
+obligated to do so.  If you do not wish to do so, delete this
+exception statement from your version. */
+
+
+package me.ag2s.epublib.zip;
+
+import java.util.Calendar;
+import java.util.Date;
+
+/**
+ * This class represents a member of a zip archive.  ZipFile and
+ * ZipInputStream will give you instances of this class as information
+ * about the members in an archive.  On the other hand ZipOutputStream
+ * needs an instance of this class to create a new member.
+ *
+ * @author Jochen Hoenicke
+ */
+public class ZipEntry implements ZipConstants, Cloneable {
+  private static final int KNOWN_SIZE = 1;
+  private static final int KNOWN_CSIZE = 2;
+  private static final int KNOWN_CRC = 4;
+  private static final int KNOWN_TIME = 8;
+
+  private static Calendar cal;
+
+  private final String name;
+  private int size;
+  private int compressedSize;
+  private int crc;
+  private int dostime;
+  private short known = 0;
+  private short method = -1;
+  private byte[] extra = null;
+  private String comment = null;
+
+  int flags;              /* used by ZipOutputStream */
+  int offset;             /* used by ZipFile and ZipOutputStream */
+
+
+  /**
+   * Compression method.  This method doesn't compress at all.
+   */
+  public final static int STORED = 0;
+  /**
+   * Compression method.  This method uses the Deflater.
+   */
+  public final static int DEFLATED = 8;
+
+  /**
+   * Creates a zip entry with the given name.
+   *
+   * @param name the name. May include directory components separated
+   *             by '/'.
+   * @throws NullPointerException     when name is null.
+   * @throws IllegalArgumentException when name is bigger then 65535 chars.
+   */
+  public ZipEntry(String name) {
+    int length = name.length();
+    if (length > 65535)
+      throw new IllegalArgumentException("name length is " + length);
+    this.name = name;
+  }
+
+  /**
+   * Creates a copy of the given zip entry.
+   *
+   * @param e the entry to copy.
+   */
+  public ZipEntry(ZipEntry e) {
+    name = e.name;
+    known = e.known;
+    size = e.size;
+    compressedSize = e.compressedSize;
+    crc = e.crc;
+    dostime = e.dostime;
+    method = e.method;
+    extra = e.extra;
+    comment = e.comment;
+  }
+
+  final void setDOSTime(int dostime) {
+    this.dostime = dostime;
+    known |= KNOWN_TIME;
+  }
+
+  final int getDOSTime() {
+    if ((known & KNOWN_TIME) == 0)
+      return 0;
+    else
+      return dostime;
+  }
+
+  /**
+   * Creates a copy of this zip entry.
+   */
+  /**
+   * Clones the entry.
+   */
+  public Object clone() {
+    try {
+      // The JCL says that the `extra' field is also copied.
+      ZipEntry clone = (ZipEntry) super.clone();
+      if (extra != null)
+        clone.extra = (byte[]) extra.clone();
+      return clone;
+    } catch (CloneNotSupportedException ex) {
+      throw new InternalError();
+    }
+  }
+
+  /**
+   * Returns the entry name.  The path components in the entry are
+   * always separated by slashes ('/').
+   */
+  public String getName() {
+    return name;
+  }
+
+  /**
+   * Sets the time of last modification of the entry.
+   *
+   * @time the time of last modification of the entry.
+   */
+  public void setTime(long time) {
+    Calendar cal = getCalendar();
+    synchronized (cal) {
+      cal.setTime(new Date(time * 1000L));
+      dostime = (cal.get(Calendar.YEAR) - 1980 & 0x7f) << 25
+              | (cal.get(Calendar.MONTH) + 1) << 21
+              | (cal.get(Calendar.DAY_OF_MONTH)) << 16
+              | (cal.get(Calendar.HOUR_OF_DAY)) << 11
+              | (cal.get(Calendar.MINUTE)) << 5
+              | (cal.get(Calendar.SECOND)) >> 1;
+    }
+    dostime = (int) (dostime / 1000L);
+    this.known |= KNOWN_TIME;
+  }
+
+  /**
+   * Gets the time of last modification of the entry.
+   *
+   * @return the time of last modification of the entry, or -1 if unknown.
+   */
+  public long getTime() {
+    if ((known & KNOWN_TIME) == 0)
+      return -1;
+
+    int sec = 2 * (dostime & 0x1f);
+    int min = (dostime >> 5) & 0x3f;
+    int hrs = (dostime >> 11) & 0x1f;
+    int day = (dostime >> 16) & 0x1f;
+    int mon = ((dostime >> 21) & 0xf) - 1;
+    int year = ((dostime >> 25) & 0x7f) + 1980; /* since 1900 */
+
+    try {
+      cal = getCalendar();
+      synchronized (cal) {
+        cal.set(year, mon, day, hrs, min, sec);
+        return cal.getTime().getTime();
+      }
+    } catch (RuntimeException ex) {
+      /* Ignore illegal time stamp */
+      known &= ~KNOWN_TIME;
+      return -1;
+    }
+  }
+
+  private static synchronized Calendar getCalendar() {
+    if (cal == null)
+      cal = Calendar.getInstance();
+
+    return cal;
+  }
+
+  /**
+   * Sets the size of the uncompressed data.
+   *
+   * @throws IllegalArgumentException if size is not in 0..0xffffffffL
+   */
+  public void setSize(long size) {
+    if ((size & 0xffffffff00000000L) != 0)
+      throw new IllegalArgumentException();
+    this.size = (int) size;
+    this.known |= KNOWN_SIZE;
+  }
+
+  /**
+   * Gets the size of the uncompressed data.
+   *
+   * @return the size or -1 if unknown.
+   */
+  public long getSize() {
+    return (known & KNOWN_SIZE) != 0 ? size & 0xffffffffL : -1L;
+  }
+
+  /**
+   * Sets the size of the compressed data.
+   *
+   * @throws IllegalArgumentException if size is not in 0..0xffffffffL
+   */
+  public void setCompressedSize(long csize) {
+    if ((csize & 0xffffffff00000000L) != 0)
+      throw new IllegalArgumentException();
+    this.compressedSize = (int) csize;
+    this.known |= KNOWN_CSIZE;
+  }
+
+  /**
+   * Gets the size of the compressed data.
+   *
+   * @return the size or -1 if unknown.
+   */
+  public long getCompressedSize() {
+    return (known & KNOWN_CSIZE) != 0 ? compressedSize & 0xffffffffL : -1L;
+  }
+
+  /**
+   * Sets the crc of the uncompressed data.
+   *
+   * @throws IllegalArgumentException if crc is not in 0..0xffffffffL
+   */
+  public void setCrc(long crc) {
+    if ((crc & 0xffffffff00000000L) != 0)
+      throw new IllegalArgumentException();
+    this.crc = (int) crc;
+    this.known |= KNOWN_CRC;
+  }
+
+  /**
+   * Gets the crc of the uncompressed data.
+   *
+   * @return the crc or -1 if unknown.
+   */
+  public long getCrc() {
+    return (known & KNOWN_CRC) != 0 ? crc & 0xffffffffL : -1L;
+  }
+
+  /**
+   * Sets the compression method.  Only DEFLATED and STORED are
+   * supported.
+   *
+   * @throws IllegalArgumentException if method is not supported.
+   * @see ZipOutputStream#DEFLATED
+   * @see ZipOutputStream#STORED
+   */
+  public void setMethod(int method) {
+    if (method != ZipOutputStream.STORED
+            && method != ZipOutputStream.DEFLATED)
+      throw new IllegalArgumentException();
+    this.method = (short) method;
+  }
+
+  /**
+   * Gets the compression method.
+   *
+   * @return the compression method or -1 if unknown.
+   */
+  public int getMethod() {
+    return method;
+  }
+
+  /**
+   * Sets the extra data.
+   *
+   * @throws IllegalArgumentException if extra is longer than 0xffff bytes.
+   */
+  public void setExtra(byte[] extra) {
+    if (extra == null) {
+      this.extra = null;
+      return;
+    }
+
+    if (extra.length > 0xffff)
+      throw new IllegalArgumentException();
+    this.extra = extra;
+    try {
+      int pos = 0;
+      while (pos < extra.length) {
+        int sig = (extra[pos++] & 0xff)
+                | (extra[pos++] & 0xff) << 8;
+        int len = (extra[pos++] & 0xff)
+                | (extra[pos++] & 0xff) << 8;
+        if (sig == 0x5455) {
+          /* extended time stamp */
+          int flags = extra[pos];
+          if ((flags & 1) != 0) {
+            long time = ((extra[pos + 1] & 0xff)
+                    | (extra[pos + 2] & 0xff) << 8
+                    | (extra[pos + 3] & 0xff) << 16
+                    | (extra[pos + 4] & 0xff) << 24);
+            setTime(time);
+          }
+        }
+        pos += len;
+      }
+    } catch (ArrayIndexOutOfBoundsException ex) {
+      /* be lenient */
+      return;
+    }
+  }
+
+  /**
+   * Gets the extra data.
+   *
+   * @return the extra data or null if not set.
+   */
+  public byte[] getExtra() {
+    return extra;
+  }
+
+  /**
+   * Sets the entry comment.
+   *
+   * @throws IllegalArgumentException if comment is longer than 0xffff.
+   */
+  public void setComment(String comment) {
+    if (comment != null && comment.length() > 0xffff)
+      throw new IllegalArgumentException();
+    this.comment = comment;
+  }
+
+  /**
+   * Gets the comment.
+   *
+   * @return the comment or null if not set.
+   */
+  public String getComment() {
+    return comment;
+  }
+
+  /**
+   * Gets true, if the entry is a directory.  This is solely
+   * determined by the name, a trailing slash '/' marks a directory.
+   */
+  public boolean isDirectory() {
+    int nlen = name.length();
+    return nlen > 0 && name.charAt(nlen - 1) == '/';
+  }
+
+  /**
+   * Gets the string representation of this ZipEntry.  This is just
+   * the name as returned by getName().
+   */
+  public String toString() {
+    return name;
+  }
+
+  /**
+   * Gets the hashCode of this ZipEntry.  This is just the hashCode
+   * of the name.  Note that the equals method isn't changed, though.
+   */
+  public int hashCode() {
+    return name.hashCode();
+  }
+}

epublib/src/main/java/me/ag2s/epublib/zip/ZipException.java

@@ -0,0 +1,69 @@
+/* ZipException.java - exception representing a zip related error
+   Copyright (C) 1998, 1999, 2000, 2001, 2002 Free Software Foundation, Inc.
+
+This file is part of GNU Classpath.
+
+GNU Classpath is free software; you can redistribute it and/or modify
+it under the terms of the GNU General Public License as published by
+the Free Software Foundation; either version 2, or (at your option)
+any later version.
+
+GNU Classpath is distributed in the hope that it will be useful, but
+WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+General Public License for more details.
+
+You should have received a copy of the GNU General Public License
+along with GNU Classpath; see the file COPYING.  If not, write to the
+Free Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
+02111-1307 USA.
+
+Linking this library statically or dynamically with other modules is
+making a combined work based on this library.  Thus, the terms and
+conditions of the GNU General Public License cover the whole
+combination.
+
+As a special exception, the copyright holders of this library give you
+permission to link this library with independent modules to produce an
+executable, regardless of the license terms of these independent
+modules, and to copy and distribute the resulting executable under
+terms of your choice, provided that you also meet, for each linked
+independent module, the terms and conditions of the license of that
+module.  An independent module is a module which is not derived from
+or based on this library.  If you modify this library, you may extend
+this exception to your version of the library, but you are not
+obligated to do so.  If you do not wish to do so, delete this
+exception statement from your version. */
+
+package me.ag2s.epublib.zip;
+
+import java.io.IOException;
+
+/**
+ * Thrown during the creation or input of a zip file.
+ *
+ * @author Jochen Hoenicke
+ * @author Per Bothner
+ * @status updated to 1.4
+ */
+public class ZipException extends IOException {
+    /**
+     * Compatible with JDK 1.0+.
+     */
+    private static final long serialVersionUID = 8000196834066748623L;
+
+    /**
+     * Create an exception without a message.
+     */
+    public ZipException() {
+    }
+
+    /**
+     * Create an exception with a message.
+     *
+     * @param msg the message
+     */
+    public ZipException(String msg) {
+        super(msg);
+    }
+}

epublib/src/main/java/me/ag2s/epublib/zip/ZipFile.java

@@ -0,0 +1,526 @@
+/* me.ag2s.epublib.zip.ZipFile
+   Copyright (C) 2001, 2002, 2003 Free Software Foundation, Inc.
+
+This file is part of GNU Classpath.
+
+GNU Classpath is free software; you can redistribute it and/or modify
+it under the terms of the GNU General Public License as published by
+the Free Software Foundation; either version 2, or (at your option)
+any later version.
+
+GNU Classpath is distributed in the hope that it will be useful, but
+WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+General Public License for more details.
+
+You should have received a copy of the GNU General Public License
+along with GNU Classpath; see the file COPYING.  If not, write to the
+Free Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
+02111-1307 USA.
+
+Linking this library statically or dynamically with other modules is
+making a combined work based on this library.  Thus, the terms and
+conditions of the GNU General Public License cover the whole
+combination.
+
+As a special exception, the copyright holders of this library give you
+permission to link this library with independent modules to produce an
+executable, regardless of the license terms of these independent
+modules, and to copy and distribute the resulting executable under
+terms of your choice, provided that you also meet, for each linked
+independent module, the terms and conditions of the license of that
+module.  An independent module is a module which is not derived from
+or based on this library.  If you modify this library, you may extend
+this exception to your version of the library, but you are not
+obligated to do so.  If you do not wish to do so, delete this
+exception statement from your version. */
+
+package me.ag2s.epublib.zip;
+
+import android.content.Context;
+import android.net.Uri;
+import android.system.ErrnoException;
+
+import androidx.annotation.NonNull;
+
+import java.io.BufferedInputStream;
+import java.io.Closeable;
+import java.io.DataInput;
+import java.io.EOFException;
+import java.io.IOException;
+import java.io.InputStream;
+import java.util.Enumeration;
+import java.util.HashMap;
+import java.util.Iterator;
+import java.util.NoSuchElementException;
+
+/**
+ * This class represents a Zip archive.  You can ask for the contained
+ * entries, or get an input stream for a file entry.  The entry is
+ * automatically decompressed.
+ * <p>
+ * This class is thread safe:  You can open input streams for arbitrary
+ * entries in different threads.
+ *
+ * @author Jochen Hoenicke
+ * @author Artur Biesiadowski
+ */
+public class ZipFile implements ZipConstants, Closeable {
+
+    /**
+     * Mode flag to open a zip file for reading.
+     */
+    public static final int OPEN_READ = 0x1;
+
+    /**
+     * Mode flag to delete a zip file after reading.
+     */
+    public static final int OPEN_DELETE = 0x4;
+
+    @NonNull
+    public Context getContext() {
+        return context;
+    }
+
+    public Uri getUri() {
+        return Uri.parse(name);
+    }
+
+
+    @NonNull
+    private final Context context;
+
+    // Name of this zip file.
+    @NonNull
+    private final String name;
+
+    // File from which zip entries are read.
+    @NonNull
+    private final  /*RandomAccessFile*/ AndroidRandomReadableFile araf;
+
+
+    // The entries of this zip file when initialized and not yet closed.
+    private HashMap<String, ZipEntry> entries;
+
+    private boolean closed = false;
+
+    /**
+     * Opens a Zip file with the given name for reading.
+     *
+     * @throws IOException  if a i/o error occured.
+     * @throws ZipException if the file doesn't contain a valid zip
+     *                      archive.
+     */
+    public ZipFile(@NonNull Context context, @NonNull Uri uri) throws ZipException, IOException {
+        this.context = context;
+        this.araf = new AndroidRandomReadableFile(context, uri);
+        this.name = uri.toString();
+    }
+
+
+    /**
+     * Opens a Zip file reading the given File in the given mode.
+     *
+     * If the OPEN_DELETE mode is specified, the zip file will be deleted at
+     * some time moment after it is opened. It will be deleted before the zip
+     * file is closed or the Virtual Machine exits.
+     *
+     * The contents of the zip file will be accessible until it is closed.
+     *
+     * The OPEN_DELETE mode is currently unimplemented in this library
+     *
+     * @since JDK1.3
+     * @param mode Must be one of OPEN_READ or OPEN_READ | OPEN_DELETE
+     *
+     * @exception IOException if a i/o error occured.
+     * @exception ZipException if the file doesn't contain a valid zip
+     * archive.
+     */
+//  public ZipFile(File file, int mode) throws ZipException, IOException
+//  {
+//    if ((mode & OPEN_DELETE) != 0)
+//      {
+//	throw new IllegalArgumentException
+//	  ("OPEN_DELETE mode not supported yet in me.ag2s.epublib.zip.ZipFile");
+//      }
+//    this.raf = new RandomAccessFile(file, "r");
+//    this.name = file.getPath();
+//  }
+
+    /**
+     * Read an unsigned short in little endian byte order from the given
+     * DataInput stream using the given byte buffer.
+     *
+     * @param di DataInput stream to read from.
+     * @param b  the byte buffer to read in (must be at least 2 bytes long).
+     * @return The value read.
+     * @throws IOException  if a i/o error occured.
+     * @throws EOFException if the file ends prematurely
+     */
+    private final int readLeShort(DataInput di, byte[] b) throws IOException {
+        di.readFully(b, 0, 2);
+        return (b[0] & 0xff) | (b[1] & 0xff) << 8;
+    }
+
+    /**
+     * Read an int in little endian byte order from the given
+     * DataInput stream using the given byte buffer.
+     *
+     * @param di DataInput stream to read from.
+     * @param b  the byte buffer to read in (must be at least 4 bytes long).
+     * @return The value read.
+     * @throws IOException  if a i/o error occured.
+     * @throws EOFException if the file ends prematurely
+     */
+    private final int readLeInt(DataInput di, byte[] b) throws IOException {
+        di.readFully(b, 0, 4);
+        return ((b[0] & 0xff) | (b[1] & 0xff) << 8)
+                | ((b[2] & 0xff) | (b[3] & 0xff) << 8) << 16;
+    }
+
+
+    /**
+     * Read an unsigned short in little endian byte order from the given
+     * byte buffer at the given offset.
+     *
+     * @param b   the byte array to read from.
+     * @param off the offset to read from.
+     * @return The value read.
+     */
+    private final int readLeShort(byte[] b, int off) {
+        return (b[off] & 0xff) | (b[off + 1] & 0xff) << 8;
+    }
+
+    /**
+     * Read an int in little endian byte order from the given
+     * byte buffer at the given offset.
+     *
+     * @param b   the byte array to read from.
+     * @param off the offset to read from.
+     * @return The value read.
+     */
+    private final int readLeInt(byte[] b, int off) {
+        return ((b[off] & 0xff) | (b[off + 1] & 0xff) << 8)
+                | ((b[off + 2] & 0xff) | (b[off + 3] & 0xff) << 8) << 16;
+    }
+
+
+    /**
+     * Read the central directory of a zip file and fill the entries
+     * array.  This is called exactly once when first needed. It is called
+     * while holding the lock on <code>raf</code>.
+     *
+     * @throws IOException  if a i/o error occured.
+     * @throws ZipException if the central directory is malformed
+     */
+    private void readEntries() throws ZipException, IOException, ErrnoException {
+        /* Search for the End Of Central Directory.  When a zip comment is
+         * present the directory may start earlier.
+         * FIXME: This searches the whole file in a very slow manner if the
+         * file isn't a zip file.
+         */
+        long pos = araf.length() - ENDHDR;
+        byte[] ebs = new byte[CENHDR];
+
+        do {
+            if (pos < 0)
+                throw new ZipException
+                        ("central directory not found, probably not a zip file: " + name);
+            araf.seek(pos--);
+        }
+        while (readLeInt(araf, ebs) != ENDSIG);
+
+        if (araf.skipBytes(ENDTOT - ENDNRD) != ENDTOT - ENDNRD)
+            throw new EOFException(name);
+        int count = readLeShort(araf, ebs);
+        if (araf.skipBytes(ENDOFF - ENDSIZ) != ENDOFF - ENDSIZ)
+            throw new EOFException(name);
+        int centralOffset = readLeInt(araf, ebs);
+
+        entries = new HashMap<>(count + count / 2);
+        araf.seek(centralOffset);
+
+        byte[] buffer = new byte[16];
+        for (int i = 0; i < count; i++) {
+            araf.readFully(ebs);
+            if (readLeInt(ebs, 0) != CENSIG)
+                throw new ZipException("Wrong Central Directory signature: " + name);
+
+            int method = readLeShort(ebs, CENHOW);
+            int dostime = readLeInt(ebs, CENTIM);
+            int crc = readLeInt(ebs, CENCRC);
+            int csize = readLeInt(ebs, CENSIZ);
+            int size = readLeInt(ebs, CENLEN);
+            int nameLen = readLeShort(ebs, CENNAM);
+            int extraLen = readLeShort(ebs, CENEXT);
+            int commentLen = readLeShort(ebs, CENCOM);
+
+            int offset = readLeInt(ebs, CENOFF);
+
+            int needBuffer = Math.max(nameLen, commentLen);
+            if (buffer.length < needBuffer)
+                buffer = new byte[needBuffer];
+
+            araf.readFully(buffer, 0, nameLen);
+            String name = new String(buffer, 0, 0, nameLen);
+
+            ZipEntry entry = new ZipEntry(name);
+            entry.setMethod(method);
+            entry.setCrc(crc & 0xffffffffL);
+            entry.setSize(size & 0xffffffffL);
+            entry.setCompressedSize(csize & 0xffffffffL);
+            entry.setDOSTime(dostime);
+            if (extraLen > 0) {
+                byte[] extra = new byte[extraLen];
+                araf.readFully(extra);
+                entry.setExtra(extra);
+            }
+            if (commentLen > 0) {
+                araf.readFully(buffer, 0, commentLen);
+                entry.setComment(new String(buffer, 0, commentLen));
+            }
+            entry.offset = offset;
+            entries.put(name, entry);
+        }
+    }
+
+    /**
+     * Closes the ZipFile.  This also closes all input streams given by
+     * this class.  After this is called, no further method should be
+     * called.
+     *
+     * @throws IOException if a i/o error occured.
+     */
+    @Override
+    public void close() throws IOException {
+        synchronized (araf) {
+            closed = true;
+            entries = null;
+            araf.close();
+        }
+    }
+
+    /**
+     * Calls the <code>close()</code> method when this ZipFile has not yet
+     * been explicitly closed.
+     */
+    protected void finalize() throws IOException {
+        if (!closed && araf != null) close();
+    }
+
+    /**
+     * Returns an enumeration of all Zip entries in this Zip file.
+     */
+    public Enumeration<? extends ZipEntry> entries() {
+        try {
+            return new ZipEntryEnumeration(getEntries().values().iterator());
+        } catch (IOException ioe) {
+            return null;
+        }
+    }
+
+    /**
+     * Checks that the ZipFile is still open and reads entries when necessary.
+     *
+     * @throws IllegalStateException when the ZipFile has already been closed.
+     * @throws IOException,          ErrnoException when the entries could not be read.
+     */
+    private HashMap<String, ZipEntry> getEntries() throws IOException {
+        synchronized (araf) {
+            if (closed)
+                throw new IllegalStateException("ZipFile has closed: " + name);
+
+            if (entries == null) {
+                try {
+                    readEntries();
+                } catch (ErrnoException e) {
+                    e.printStackTrace();
+                }
+            }
+
+            return entries;
+        }
+    }
+
+    /**
+     * Searches for a zip entry in this archive with the given name.
+     *
+     * @param name May contain directory components separated by
+     *             slashes ('/').
+     * @return the zip entry, or null if no entry with that name exists.
+     */
+    public ZipEntry getEntry(String name) {
+        try {
+            HashMap<String, ZipEntry> entries = getEntries();
+            ZipEntry entry = (ZipEntry) entries.get(name);
+            return entry != null ? (ZipEntry) entry.clone() : null;
+        } catch (IOException ioe) {
+            return null;
+        }
+    }
+
+
+    //access should be protected by synchronized(raf)
+    private final byte[] locBuf = new byte[LOCHDR];
+
+    /**
+     * Checks, if the local header of the entry at index i matches the
+     * central directory, and returns the offset to the data.
+     *
+     * @param entry to check.
+     * @return the start offset of the (compressed) data.
+     * @throws IOException  if a i/o error occured.
+     * @throws ZipException if the local header doesn't match the
+     *                      central directory header
+     */
+    private long checkLocalHeader(ZipEntry entry) throws IOException {
+        synchronized (araf) {
+            try {
+                araf.seek(entry.offset);
+            } catch (IOException e) {
+                e.printStackTrace();
+            }
+            araf.readFully(locBuf);
+
+            if (readLeInt(locBuf, 0) != LOCSIG)
+                throw new ZipException("Wrong Local header signature: " + name);
+
+            if (entry.getMethod() != readLeShort(locBuf, LOCHOW))
+                throw new ZipException("Compression method mismatch: " + name);
+
+            if (entry.getName().length() != readLeShort(locBuf, LOCNAM))
+                throw new ZipException("file name length mismatch: " + name);
+
+            int extraLen = entry.getName().length() + readLeShort(locBuf, LOCEXT);
+            return entry.offset + LOCHDR + extraLen;
+        }
+    }
+
+    /**
+     * Creates an input stream reading the given zip entry as
+     * uncompressed data.  Normally zip entry should be an entry
+     * returned by getEntry() or entries().
+     *
+     * @param entry the entry to create an InputStream for.
+     * @return the input stream.
+     * @throws IOException  if a i/o error occured.
+     * @throws ZipException if the Zip archive is malformed.
+     */
+    public InputStream getInputStream(ZipEntry entry) throws IOException {
+        HashMap<String, ZipEntry> entries = getEntries();
+        String name = entry.getName();
+        ZipEntry zipEntry = entries.get(name);
+        if (zipEntry == null)
+            throw new NoSuchElementException(name);
+
+        long start = checkLocalHeader(zipEntry);
+        int method = zipEntry.getMethod();
+        InputStream is = new BufferedInputStream(new PartialInputStream
+                (araf, start, zipEntry.getCompressedSize()));
+        switch (method) {
+            case ZipOutputStream.STORED:
+                return is;
+            case ZipOutputStream.DEFLATED:
+                return new InflaterInputStream(is, new Inflater(true));
+            default:
+                throw new ZipException("Unknown compression method " + method);
+        }
+    }
+
+    /**
+     * Returns the (path) name of this zip file.
+     */
+    @NonNull
+    public String getName() {
+        return name;
+    }
+
+    /**
+     * Returns the number of entries in this zip file.
+     */
+    public int size() {
+        try {
+            return getEntries().size();
+        } catch (IOException ioe) {
+            return 0;
+        }
+    }
+
+    private static class ZipEntryEnumeration implements Enumeration<ZipEntry> {
+        private final Iterator<ZipEntry> elements;
+
+        public ZipEntryEnumeration(Iterator<ZipEntry> elements) {
+            this.elements = elements;
+        }
+
+        public boolean hasMoreElements() {
+            return elements.hasNext();
+        }
+
+        public ZipEntry nextElement() {
+            /* We return a clone, just to be safe that the user doesn't
+             * change the entry.
+             */
+            return (ZipEntry) elements.next().clone();
+        }
+    }
+
+    private static class PartialInputStream extends InputStream {
+        private final /*RandomAccessFile*/ AndroidRandomReadableFile raf;
+        long filepos, end;
+
+        public PartialInputStream(AndroidRandomReadableFile raf, long start, long len) {
+            this.raf = raf;
+            filepos = start;
+            end = start + len;
+        }
+
+        public int available() {
+            long amount = end - filepos;
+            if (amount > Integer.MAX_VALUE)
+                return Integer.MAX_VALUE;
+            return (int) amount;
+        }
+
+        public int read() throws IOException {
+            if (filepos == end)
+                return -1;
+            synchronized (raf) {
+                try {
+                    raf.seek(filepos++);
+                } catch (IOException e) {
+                    e.printStackTrace();
+                }
+                return raf.read();
+            }
+        }
+
+        public int read(byte[] b, int off, int len) throws IOException {
+            if (len > end - filepos) {
+                len = (int) (end - filepos);
+                if (len == 0)
+                    return -1;
+            }
+            synchronized (raf) {
+                try {
+                    raf.seek(filepos);
+                } catch (IOException e) {
+                    e.printStackTrace();
+                }
+                int count = raf.read(b, off, len);
+                if (count > 0)
+                    filepos += len;
+                return count;
+            }
+        }
+
+        public long skip(long amount) {
+            if (amount < 0)
+                throw new IllegalArgumentException();
+            if (amount > end - filepos)
+                amount = end - filepos;
+            filepos += amount;
+            return amount;
+        }
+    }
+}

epublib/src/main/java/me/ag2s/epublib/zip/ZipInputStream.java

@@ -0,0 +1,344 @@
+/* me.ag2s.epublib.zip.ZipInputStream
+   Copyright (C) 2001, 2002, 2003 Free Software Foundation, Inc.
+
+This file is part of GNU Classpath.
+
+GNU Classpath is free software; you can redistribute it and/or modify
+it under the terms of the GNU General Public License as published by
+the Free Software Foundation; either version 2, or (at your option)
+any later version.
+
+GNU Classpath is distributed in the hope that it will be useful, but
+WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+General Public License for more details.
+
+You should have received a copy of the GNU General Public License
+along with GNU Classpath; see the file COPYING.  If not, write to the
+Free Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
+02111-1307 USA.
+
+Linking this library statically or dynamically with other modules is
+making a combined work based on this library.  Thus, the terms and
+conditions of the GNU General Public License cover the whole
+combination.
+
+As a special exception, the copyright holders of this library give you
+permission to link this library with independent modules to produce an
+executable, regardless of the license terms of these independent
+modules, and to copy and distribute the resulting executable under
+terms of your choice, provided that you also meet, for each linked
+independent module, the terms and conditions of the license of that
+module.  An independent module is a module which is not derived from
+or based on this library.  If you modify this library, you may extend
+this exception to your version of the library, but you are not
+obligated to do so.  If you do not wish to do so, delete this
+exception statement from your version. */
+
+
+package me.ag2s.epublib.zip;
+
+import java.io.EOFException;
+import java.io.IOException;
+import java.io.InputStream;
+
+/**
+ * This is a FilterInputStream that reads the files in an zip archive
+ * one after another.  It has a special method to get the zip entry of
+ * the next file.  The zip entry contains information about the file name
+ * size, compressed size, CRC, etc.
+ * <p>
+ * It includes support for STORED and DEFLATED entries.
+ *
+ * @author Jochen Hoenicke
+ */
+public class ZipInputStream extends InflaterInputStream implements ZipConstants {
+    private CRC32 crc = new CRC32();
+    private ZipEntry entry = null;
+
+    private int csize;
+    private int size;
+    private int method;
+    private int flags;
+    private int avail;
+    private boolean entryAtEOF;
+
+    /**
+     * Creates a new Zip input stream, reading a zip archive.
+     */
+    public ZipInputStream(InputStream in) {
+        super(in, new Inflater(true));
+    }
+
+    private void fillBuf() throws IOException {
+        avail = len = in.read(buf, 0, buf.length);
+    }
+
+    private int readBuf(byte[] out, int offset, int length) throws IOException {
+        if (avail <= 0) {
+            fillBuf();
+            if (avail <= 0)
+                return -1;
+        }
+        if (length > avail)
+            length = avail;
+        System.arraycopy(buf, len - avail, out, offset, length);
+        avail -= length;
+        return length;
+    }
+
+    private void readFully(byte[] out) throws IOException {
+        int off = 0;
+        int len = out.length;
+        while (len > 0) {
+            int count = readBuf(out, off, len);
+            if (count == -1)
+                throw new EOFException();
+            off += count;
+            len -= count;
+        }
+    }
+
+    private final int readLeByte() throws IOException {
+        if (avail <= 0) {
+            fillBuf();
+            if (avail <= 0)
+                throw new ZipException("EOF in header");
+        }
+        return buf[len - avail--] & 0xff;
+    }
+
+    /**
+     * Read an unsigned short in little endian byte order.
+     */
+    private final int readLeShort() throws IOException {
+        return readLeByte() | (readLeByte() << 8);
+    }
+
+    /**
+     * Read an int in little endian byte order.
+     */
+    private final int readLeInt() throws IOException {
+        return readLeShort() | (readLeShort() << 16);
+    }
+
+    /**
+     * Open the next entry from the zip archive, and return its description.
+     * If the previous entry wasn't closed, this method will close it.
+     */
+    public ZipEntry getNextEntry() throws IOException {
+        if (crc == null)
+            throw new IOException("Stream closed.");
+        if (entry != null)
+            closeEntry();
+
+        int header = readLeInt();
+        if (header == CENSIG) {
+            /* Central Header reached. */
+            close();
+            return null;
+        }
+        if (header != LOCSIG)
+            throw new ZipException("Wrong Local header signature: "
+                    + Integer.toHexString(header));
+        /* skip version */
+        readLeShort();
+        flags = readLeShort();
+        method = readLeShort();
+        int dostime = readLeInt();
+        int crc = readLeInt();
+        csize = readLeInt();
+        size = readLeInt();
+        int nameLen = readLeShort();
+        int extraLen = readLeShort();
+
+        if (method == ZipOutputStream.STORED && csize != size)
+            throw new ZipException("Stored, but compressed != uncompressed");
+
+
+        byte[] buffer = new byte[nameLen];
+        readFully(buffer);
+        String name = new String(buffer);
+
+        entry = createZipEntry(name);
+        entryAtEOF = false;
+        entry.setMethod(method);
+        if ((flags & 8) == 0) {
+            entry.setCrc(crc & 0xffffffffL);
+            entry.setSize(size & 0xffffffffL);
+            entry.setCompressedSize(csize & 0xffffffffL);
+        }
+        entry.setDOSTime(dostime);
+        if (extraLen > 0) {
+            byte[] extra = new byte[extraLen];
+            readFully(extra);
+            entry.setExtra(extra);
+        }
+
+        if (method == ZipOutputStream.DEFLATED && avail > 0) {
+            System.arraycopy(buf, len - avail, buf, 0, avail);
+            len = avail;
+            avail = 0;
+            inf.setInput(buf, 0, len);
+        }
+        return entry;
+    }
+
+    private void readDataDescr() throws IOException {
+        if (readLeInt() != EXTSIG)
+            throw new ZipException("Data descriptor signature not found");
+        entry.setCrc(readLeInt() & 0xffffffffL);
+        csize = readLeInt();
+        size = readLeInt();
+        entry.setSize(size & 0xffffffffL);
+        entry.setCompressedSize(csize & 0xffffffffL);
+    }
+
+    /**
+     * Closes the current zip entry and moves to the next one.
+     */
+    public void closeEntry() throws IOException {
+        if (crc == null)
+            throw new IOException("Stream closed.");
+        if (entry == null)
+            return;
+
+        if (method == ZipOutputStream.DEFLATED) {
+            if ((flags & 8) != 0) {
+                /* We don't know how much we must skip, read until end. */
+                byte[] tmp = new byte[2048];
+                while (read(tmp) > 0)
+                    ;
+                /* read will close this entry */
+                return;
+            }
+            csize -= inf.getTotalIn();
+            avail = inf.getRemaining();
+        }
+
+        if (avail > csize && csize >= 0)
+            avail -= csize;
+        else {
+            csize -= avail;
+            avail = 0;
+            while (csize != 0) {
+                long skipped = in.skip(csize & 0xffffffffL);
+                if (skipped <= 0)
+                    throw new ZipException("zip archive ends early.");
+                csize -= skipped;
+            }
+        }
+
+        size = 0;
+        crc.reset();
+        if (method == ZipOutputStream.DEFLATED)
+            inf.reset();
+        entry = null;
+        entryAtEOF = true;
+    }
+
+    public int available() throws IOException {
+        return entryAtEOF ? 0 : 1;
+    }
+
+    /**
+     * Reads a byte from the current zip entry.
+     *
+     * @return the byte or -1 on EOF.
+     * @throws IOException  if a i/o error occured.
+     * @throws ZipException if the deflated stream is corrupted.
+     */
+    public int read() throws IOException {
+        byte[] b = new byte[1];
+        if (read(b, 0, 1) <= 0)
+            return -1;
+        return b[0] & 0xff;
+    }
+
+    /**
+     * Reads a block of bytes from the current zip entry.
+     *
+     * @return the number of bytes read (may be smaller, even before
+     * EOF), or -1 on EOF.
+     * @throws IOException  if a i/o error occured.
+     * @throws ZipException if the deflated stream is corrupted.
+     */
+    public int read(byte[] b, int off, int len) throws IOException {
+        if (len == 0)
+            return 0;
+        if (crc == null)
+            throw new IOException("Stream closed.");
+        if (entry == null)
+            return -1;
+        boolean finished = false;
+        switch (method) {
+            case ZipOutputStream.DEFLATED:
+                len = super.read(b, off, len);
+                if (len < 0) {
+                    if (!inf.finished())
+                        throw new ZipException("Inflater not finished!?");
+                    avail = inf.getRemaining();
+                    if ((flags & 8) != 0)
+                        readDataDescr();
+
+                    if (inf.getTotalIn() != csize
+                            || inf.getTotalOut() != size)
+                        throw new ZipException("size mismatch: " + csize + ";" + size + " <-> " + inf.getTotalIn() + ";" + inf.getTotalOut());
+                    inf.reset();
+                    finished = true;
+                }
+                break;
+
+            case ZipOutputStream.STORED:
+
+                if (len > csize && csize >= 0)
+                    len = csize;
+
+                len = readBuf(b, off, len);
+                if (len > 0) {
+                    csize -= len;
+                    size -= len;
+                }
+
+                if (csize == 0)
+                    finished = true;
+                else if (len < 0)
+                    throw new ZipException("EOF in stored block");
+                break;
+        }
+
+        if (len > 0)
+            crc.update(b, off, len);
+
+        if (finished) {
+            if ((crc.getValue() & 0xffffffffL) != entry.getCrc())
+                throw new ZipException("CRC mismatch");
+            crc.reset();
+            entry = null;
+            entryAtEOF = true;
+        }
+        return len;
+    }
+
+    /**
+     * Closes the zip file.
+     *
+     * @throws IOException if a i/o error occured.
+     */
+    public void close() throws IOException {
+        super.close();
+        crc = null;
+        entry = null;
+        entryAtEOF = true;
+    }
+
+    /**
+     * Creates a new zip entry for the given name.  This is equivalent
+     * to new ZipEntry(name).
+     *
+     * @param name the name of the zip entry.
+     */
+    protected ZipEntry createZipEntry(String name) {
+        return new ZipEntry(name);
+    }
+}

epublib/src/main/java/me/ag2s/epublib/zip/ZipOutputStream.java

@@ -0,0 +1,383 @@
+/* me.ag2s.epublib.zip.ZipOutputStream
+   Copyright (C) 2001 Free Software Foundation, Inc.
+
+This file is part of GNU Classpath.
+
+GNU Classpath is free software; you can redistribute it and/or modify
+it under the terms of the GNU General Public License as published by
+the Free Software Foundation; either version 2, or (at your option)
+any later version.
+
+GNU Classpath is distributed in the hope that it will be useful, but
+WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+General Public License for more details.
+
+You should have received a copy of the GNU General Public License
+along with GNU Classpath; see the file COPYING.  If not, write to the
+Free Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
+02111-1307 USA.
+
+Linking this library statically or dynamically with other modules is
+making a combined work based on this library.  Thus, the terms and
+conditions of the GNU General Public License cover the whole
+combination.
+
+As a special exception, the copyright holders of this library give you
+permission to link this library with independent modules to produce an
+executable, regardless of the license terms of these independent
+modules, and to copy and distribute the resulting executable under
+terms of your choice, provided that you also meet, for each linked
+independent module, the terms and conditions of the license of that
+module.  An independent module is a module which is not derived from
+or based on this library.  If you modify this library, you may extend
+this exception to your version of the library, but you are not
+obligated to do so.  If you do not wish to do so, delete this
+exception statement from your version. */
+
+
+package me.ag2s.epublib.zip;
+
+import java.io.IOException;
+import java.io.OutputStream;
+import java.util.ArrayList;
+
+/**
+ * This is a FilterOutputStream that writes the files into a zip
+ * archive one after another.  It has a special method to start a new
+ * zip entry.  The zip entries contains information about the file name
+ * size, compressed size, CRC, etc.
+ * <p>
+ * It includes support for STORED and DEFLATED entries.
+ * <p>
+ * This class is not thread safe.
+ *
+ * @author Jochen Hoenicke
+ */
+public class ZipOutputStream extends DeflaterOutputStream implements ZipConstants {
+    private ArrayList<ZipEntry> entries = new ArrayList<>();
+    private final CRC32 crc = new CRC32();
+    private ZipEntry curEntry = null;
+
+    private int curMethod;
+    private int size;
+    private int offset = 0;
+
+    private byte[] zipComment = new byte[0];
+    private int defaultMethod = DEFLATED;
+
+    /**
+     * Our Zip version is hard coded to 1.0 resp. 2.0
+     */
+    private final static int ZIP_STORED_VERSION = 10;
+    private final static int ZIP_DEFLATED_VERSION = 20;
+
+    /**
+     * Compression method.  This method doesn't compress at all.
+     */
+    public final static int STORED = 0;
+    /**
+     * Compression method.  This method uses the Deflater.
+     */
+    public final static int DEFLATED = 8;
+
+    /**
+     * Creates a new Zip output stream, writing a zip archive.
+     *
+     * @param out the output stream to which the zip archive is written.
+     */
+    public ZipOutputStream(OutputStream out) {
+        super(out, new Deflater(Deflater.DEFAULT_COMPRESSION, true));
+    }
+
+    /**
+     * Set the zip file comment.
+     *
+     * @param comment the comment.
+     * @throws IllegalArgumentException if encoding of comment is
+     *                                  longer than 0xffff bytes.
+     */
+    public void setComment(String comment) {
+        byte[] commentBytes;
+        commentBytes = comment.getBytes();
+        if (commentBytes.length > 0xffff)
+            throw new IllegalArgumentException("Comment too long.");
+        zipComment = commentBytes;
+    }
+
+    /**
+     * Sets default compression method.  If the Zip entry specifies
+     * another method its method takes precedence.
+     *
+     * @param method the method.
+     * @throws IllegalArgumentException if method is not supported.
+     * @see #STORED
+     * @see #DEFLATED
+     */
+    public void setMethod(int method) {
+        if (method != STORED && method != DEFLATED)
+            throw new IllegalArgumentException("Method not supported.");
+        defaultMethod = method;
+    }
+
+    /**
+     * Sets default compression level.  The new level will be activated
+     * immediately.
+     *
+     * @throws IllegalArgumentException if level is not supported.
+     * @see Deflater
+     */
+    public void setLevel(int level) {
+        def.setLevel(level);
+    }
+
+    /**
+     * Write an unsigned short in little endian byte order.
+     */
+    private final void writeLeShort(int value) throws IOException {
+        out.write(value & 0xff);
+        out.write((value >> 8) & 0xff);
+    }
+
+    /**
+     * Write an int in little endian byte order.
+     */
+    private final void writeLeInt(int value) throws IOException {
+        writeLeShort(value);
+        writeLeShort(value >> 16);
+    }
+
+    /**
+     * Starts a new Zip entry. It automatically closes the previous
+     * entry if present.  If the compression method is stored, the entry
+     * must have a valid size and crc, otherwise all elements (except
+     * name) are optional, but must be correct if present.  If the time
+     * is not set in the entry, the current time is used.
+     *
+     * @param entry the entry.
+     * @throws IOException  if an I/O error occured.
+     * @throws ZipException if stream was finished.
+     */
+    public void putNextEntry(ZipEntry entry) throws IOException {
+        if (entries == null)
+            throw new ZipException("ZipOutputStream was finished");
+
+        int method = entry.getMethod();
+        int flags = 0;
+        if (method == -1)
+            method = defaultMethod;
+
+        if (method == STORED) {
+            if (entry.getCompressedSize() >= 0) {
+                if (entry.getSize() < 0)
+                    entry.setSize(entry.getCompressedSize());
+                else if (entry.getSize() != entry.getCompressedSize())
+                    throw new ZipException
+                            ("Method STORED, but compressed size != size");
+            } else
+                entry.setCompressedSize(entry.getSize());
+
+            if (entry.getSize() < 0)
+                throw new ZipException("Method STORED, but size not set");
+            if (entry.getCrc() < 0)
+                throw new ZipException("Method STORED, but crc not set");
+        } else if (method == DEFLATED) {
+            if (entry.getCompressedSize() < 0
+                    || entry.getSize() < 0 || entry.getCrc() < 0)
+                flags |= 8;
+        }
+
+        if (curEntry != null)
+            closeEntry();
+
+        if (entry.getTime() < 0)
+            entry.setTime(System.currentTimeMillis());
+
+        entry.flags = flags;
+        entry.offset = offset;
+        entry.setMethod(method);
+        curMethod = method;
+        /* Write the local file header */
+        writeLeInt(LOCSIG);
+        writeLeShort(method == STORED
+                ? ZIP_STORED_VERSION : ZIP_DEFLATED_VERSION);
+        writeLeShort(flags);
+        writeLeShort(method);
+        writeLeInt(entry.getDOSTime());
+        if ((flags & 8) == 0) {
+            writeLeInt((int) entry.getCrc());
+            writeLeInt((int) entry.getCompressedSize());
+            writeLeInt((int) entry.getSize());
+        } else {
+            writeLeInt(0);
+            writeLeInt(0);
+            writeLeInt(0);
+        }
+        byte[] name = entry.getName().getBytes();
+        if (name.length > 0xffff)
+            throw new ZipException("Name too long.");
+        byte[] extra = entry.getExtra();
+        if (extra == null)
+            extra = new byte[0];
+        writeLeShort(name.length);
+        writeLeShort(extra.length);
+        out.write(name);
+        out.write(extra);
+
+        offset += LOCHDR + name.length + extra.length;
+
+        /* Activate the entry. */
+
+        curEntry = entry;
+        crc.reset();
+        if (method == DEFLATED)
+            def.reset();
+        size = 0;
+    }
+
+    /**
+     * Closes the current entry.
+     *
+     * @throws IOException  if an I/O error occured.
+     * @throws ZipException if no entry is active.
+     */
+    public void closeEntry() throws IOException {
+        if (curEntry == null)
+            throw new ZipException("No open entry");
+
+        /* First finish the deflater, if appropriate */
+        if (curMethod == DEFLATED)
+            super.finish();
+
+        int csize = curMethod == DEFLATED ? def.getTotalOut() : size;
+
+        if (curEntry.getSize() < 0)
+            curEntry.setSize(size);
+        else if (curEntry.getSize() != size)
+            throw new ZipException("size was " + size
+                    + ", but I expected " + curEntry.getSize());
+
+        if (curEntry.getCompressedSize() < 0)
+            curEntry.setCompressedSize(csize);
+        else if (curEntry.getCompressedSize() != csize)
+            throw new ZipException("compressed size was " + csize
+                    + ", but I expected " + curEntry.getSize());
+
+        if (curEntry.getCrc() < 0)
+            curEntry.setCrc(crc.getValue());
+        else if (curEntry.getCrc() != crc.getValue())
+            throw new ZipException("crc was " + Long.toHexString(crc.getValue())
+                    + ", but I expected "
+                    + Long.toHexString(curEntry.getCrc()));
+
+        offset += csize;
+
+        /* Now write the data descriptor entry if needed. */
+        if (curMethod == DEFLATED && (curEntry.flags & 8) != 0) {
+            writeLeInt(EXTSIG);
+            writeLeInt((int) curEntry.getCrc());
+            writeLeInt((int) curEntry.getCompressedSize());
+            writeLeInt((int) curEntry.getSize());
+            offset += EXTHDR;
+        }
+
+        entries.add(curEntry);
+        //entries.addElement(curEntry);
+        curEntry = null;
+    }
+
+    /**
+     * Writes the given buffer to the current entry.
+     *
+     * @throws IOException  if an I/O error occured.
+     * @throws ZipException if no entry is active.
+     */
+    public void write(byte[] b, int off, int len) throws IOException {
+        if (curEntry == null)
+            throw new ZipException("No open entry.");
+
+        switch (curMethod) {
+            case DEFLATED:
+                super.write(b, off, len);
+                break;
+
+            case STORED:
+                out.write(b, off, len);
+                break;
+        }
+
+        crc.update(b, off, len);
+        size += len;
+    }
+
+    /**
+     * Finishes the stream.  This will write the central directory at the
+     * end of the zip file and flush the stream.
+     *
+     * @throws IOException if an I/O error occured.
+     */
+    public void finish() throws IOException {
+        if (entries == null)
+            return;
+        if (curEntry != null)
+            closeEntry();
+
+        int numEntries = 0;
+        int sizeEntries = 0;
+
+        //Enumeration<ZipEntry> items = entries.elements();
+        //items.nextElement();
+        for (ZipEntry entry : entries) {
+            int method = entry.getMethod();
+            writeLeInt(CENSIG);
+            writeLeShort(method == STORED
+                    ? ZIP_STORED_VERSION : ZIP_DEFLATED_VERSION);
+            writeLeShort(method == STORED
+                    ? ZIP_STORED_VERSION : ZIP_DEFLATED_VERSION);
+            writeLeShort(entry.flags);
+            writeLeShort(method);
+            writeLeInt(entry.getDOSTime());
+            writeLeInt((int) entry.getCrc());
+            writeLeInt((int) entry.getCompressedSize());
+            writeLeInt((int) entry.getSize());
+
+            byte[] name = entry.getName().getBytes();
+            if (name.length > 0xffff)
+                throw new ZipException("Name too long.");
+            byte[] extra = entry.getExtra();
+            if (extra == null)
+                extra = new byte[0];
+            String strComment = entry.getComment();
+            byte[] comment = strComment != null
+                    ? strComment.getBytes() : new byte[0];
+            if (comment.length > 0xffff)
+                throw new ZipException("Comment too long.");
+
+            writeLeShort(name.length);
+            writeLeShort(extra.length);
+            writeLeShort(comment.length);
+            writeLeShort(0); /* disk number */
+            writeLeShort(0); /* internal file attr */
+            writeLeInt(0);   /* external file attr */
+            writeLeInt(entry.offset);
+
+            out.write(name);
+            out.write(extra);
+            out.write(comment);
+            numEntries++;
+            sizeEntries += CENHDR + name.length + extra.length + comment.length;
+        }
+
+        writeLeInt(ENDSIG);
+        writeLeShort(0); /* disk number */
+        writeLeShort(0); /* disk with start of central dir */
+        writeLeShort(numEntries);
+        writeLeShort(numEntries);
+        writeLeInt(sizeEntries);
+        writeLeInt(offset);
+        writeLeShort(zipComment.length);
+        out.write(zipComment);
+        out.flush();
+        entries = null;
+    }
+}