public final String getMD5(String s)
    {
        try
        {
            MessageDigest md5 = MessageDigest.getInstance("MD5");
            md5.update(s.getBytes(), 0, s.length());
            signature = new BigInteger(1, md5.digest()).toString(16);
        }
        catch(NoSuchAlgorithmException e)
        {
            e.printStackTrace();
        }
        return signature;
    }