while( (read = is.read(buffer)) > 0) {
                digest.update(buffer, 0, read);
            }
            byte[] md5sum = digest.digest();
            BigInteger bigInt = new BigInteger(1, md5sum);
            String output = bigInt.toString(16);
            if(output.length() != 32)
                output = "0" + output;
            System.out.println("MD5: " + output);

            return output;