Calculate SHA1 hash on gradle.

calcSha1.gradle

// file must be File object.
def calcSha1(file) 
{
    MessageDigest md = MessageDigest.getInstance("SHA-1");
    file.eachByte 4096, {bytes, size ->
        md.update(bytes, 0, size);
    }
    return md.digest().collect {String.format "%02x", it}.join();
}

Thanks for the useful gist! With Groovy 1.8.6 and later, line 8 can be simplified to:

return md.digest().encodeHex()