legado/app/download.gradle

import java.security.MessageDigest

apply plugin: 'de.undercouch.download'

def BASE_PATH = "https://storage.googleapis.com/chromium-cronet/android/" + CronetVersion + "/Release/cronet/"
def assetsDir = projectDir.toString() + "/src/main/assets"
def libPath = projectDir.toString() + "/cronetlib"
def soPath = projectDir.toString() + "/so"

/**
 * 从文件生成MD5
 * @param file
 * @return
 */
static def generateMD5(final file) {
    MessageDigest digest = MessageDigest.getInstance("MD5")
    file.withInputStream() { is ->
        byte[] buffer = new byte[1024]
        int numRead = 0
        while ((numRead = is.read(buffer)) > 0) {
            digest.update(buffer, 0, numRead)
        }
    }
    return String.format("%032x", new BigInteger(1, digest.digest())).toLowerCase()
}

/**
 * 下载Cronet相关的jar
 */
task downloadJar(type: Download) {
    src([
            BASE_PATH + "cronet_api.jar",
            BASE_PATH + "cronet_impl_common_java.jar",
            BASE_PATH + "cronet_impl_native_java.jar",
            BASE_PATH + "cronet_impl_platform_java.jar",
    ])
    dest libPath
    overwrite true
    onlyIfModified true
}
/**
 * 下载Cronet的arm64-v8a so
 */
task downloadARM64(type: Download) {
    src BASE_PATH + "libs/arm64-v8a/libcronet." + CronetVersion + ".so"
    dest soPath + "/arm64-v8a.so"
    overwrite true
    onlyIfModified true
}
/**
 * 下载Cronet的armeabi-v7a so
 */
task downloadARMv7(type: Download) {
    src BASE_PATH + "libs/armeabi-v7a/libcronet." + CronetVersion + ".so"
    dest soPath + "/armeabi-v7a.so"
    overwrite true
    onlyIfModified true
}
/**
 * 下载Cronet的x86_64 so
 */
task downloadX86_64(type: Download) {
    src BASE_PATH + "libs/x86_64/libcronet." + CronetVersion + ".so"
    dest soPath + "/x86_64.so"
    overwrite true
    onlyIfModified true
}
/**
 * 下载Cronet的x86 so
 */
task downloadX86(type: Download) {
    src BASE_PATH + "libs/x86/libcronet." + CronetVersion + ".so"
    dest soPath + "/x86.so"
    overwrite true
    onlyIfModified true
}

/**
 * 更新Cronet版本时执行这个task
 * 先更改gradle.properties 里面的版本号，然后再执行
 * gradlew app:downloadCronet
 */
task downloadCronet() {
    dependsOn downloadJar, downloadARM64, downloadARMv7, downloadX86_64, downloadX86

    doLast {
        StringBuilder sb = new StringBuilder("{")
        def files = new File(soPath).listFiles()
        for (File file : files) {
            println file.name.replace(".so", "")
            sb.append("\"").append(file.name.replace(".so", "")).append("\":\"").append(generateMD5(file)).append("\",")
        }
        sb.append("\"version\":\"").append(CronetVersion).append("\"}")

        println sb.toString()

        println assetsDir
        def f1 = new File(assetsDir + "/cronet.json")
        if (!f1.exists()) {
            f1.parentFile.mkdirs()
            f1.createNewFile()
        }
        f1.text = sb.toString()

    }


}