assembleResources.gradle

buildscript {
    repositories {
        jcenter()
    }
    dependencies {
        classpath 'net.lingala.zip4j:zip4j:1.3.2'
    }
}

import net.lingala.zip4j.core.ZipFile
import net.lingala.zip4j.model.ZipParameters
import net.lingala.zip4j.util.Zip4jConstants
import net.lingala.zip4j.model.FileHeader


task assembleResourcesTask << {
    android.applicationVariants.all { variant ->
        variant.outputs.each { output ->
            File out = output.outputFile
            if (out.exists()) {
                def destDir = out.absolutePath.replace(".apk", "")
                unzip(out, destDir)
                def unzipDirFile = new File(destDir)
                shrinkResources(unzipDirFile)
                zip(destDir, destDir + ".res")
                unzipDirFile.deleteDir()
            }
        }
    }
}

afterEvaluate {
    assembleResourcesTask.dependsOn tasks.find() { it.name.matches(/^assemble(.*?)Debug$/) }
    tasks.find { it.name.matches(/^compile(.*?)JavaWithJavac$/) }.each { it.enabled = false }
}


static shrinkResources1(File file) {
    def deletePattern = [".*assets.*", ".*META-INF.*", ".*\\.dex", ".*res.layout.*xml", ".*res.menu.*xml"]
    if (!file.exists()) {
        return
    }

    ZipFile zipFile = new ZipFile(file);
    def fileHeaders = zipFile.getFileHeaders()
    fileHeaders.clone().each { FileHeader fileHeader ->
        deletePattern.each { pattern ->
            def filePath = fileHeader.fileName
            if (filePath.matches(pattern)) {
                try {
                    println "Delete file ${filePath}"
                    zipFile.removeFile(fileHeader)
                } catch (Exception e) {
                    e.printStackTrace()
                    //println "Delete file ${filePath} , ${e.message}"
                    throw e
                }
            }
        }
    }

}


static shrinkResources(File file) {
    def deletePattern = [".*assets.*", ".*META-INF.*", ".*\\.dex", ".*res.layout.*xml", ".*res.menu.*xml"]
    if (!file.exists()) {
        return
    }

    if (file.isFile()) {
        deletePattern.each { pattern ->
            if (file.absolutePath.matches(pattern)) {
                println "Delete file ${file.absolutePath} , ${file.delete()}"
            }
        }
    } else {
        File[] listFile = file.listFiles()
        if (listFile == null) {
            return
        }
        listFile.each {
            shrinkResources(it)
        }
        deletePattern.each { pattern ->
            if (file.absolutePath.matches(pattern)) {
                println "Delete file ${file.absolutePath} , ${file.deleteDir()}"
            }
        }
    }
}

static void unzip(File zipFile, String dest) {
    new File(dest).mkdirs()
    ZipFile zFile = new ZipFile(zipFile);
    zFile.setFileNameCharset("UTF-8");
    zFile.extractAll(dest);
}

static void zip(String src, String dest) {
    ZipParameters parameters = new ZipParameters();
    parameters.setCompressionMethod(Zip4jConstants.COMP_DEFLATE);
    parameters.setCompressionLevel(Zip4jConstants.DEFLATE_LEVEL_NORMAL);
    def zipFile = new ZipFile(dest)
    if (zipFile.getFile()) {
        zipFile.getFile().delete()
    }
    new File(src).listFiles().each {
        if (it.isFile()) {
            zipFile.addFile(it, parameters);
        } else {
            zipFile.addFolder(it, parameters);
        }
    }

}