Amethyst-Android/build.gradle

import java.security.MessageDigest

plugins{
    id 'com.android.application' version '8.7.2' apply false
    id 'com.android.library' version '8.7.2' apply false
}

static void hashFileWithDigest(File fileToHash, MessageDigest digest){
    fileToHash.withInputStream { is ->
        byte[] buffer = new byte[8192]
        int read
        while ((read = is.read(buffer)) != -1) {
            digest.update(buffer, 0, read)
        }
    }
}

static void writeVersionFile(File jarFile, File versionFile){
    def sha1 = MessageDigest.getInstance("SHA-1")
    hashFileWithDigest(jarFile, sha1)
    versionFile.write(sha1.digest().collect { String.format("%02x", it) }.join())
}

static void writeVersionFile(File[] jarFileArray, File versionFile){
    def sha1 = MessageDigest.getInstance("SHA-1")
    jarFileArray.each {jarFile ->
        hashFileWithDigest(jarFile, sha1)
    }
    versionFile.write(sha1.digest().collect { String.format("%02x", it) }.join())
}