toMD5 - working

public String toMd5(String str) {
    try {
        MessageDigest m = MessageDigest.getInstance("MD5");
        m.update(str.getBytes(), 0, str.length());
        BigInteger i = new BigInteger(1,m.digest());
        return String.format("%1$032x", i);
    } catch (NoSuchAlgorithmException e) {
        e.printStackTrace();
    }
        return null;
    }