MD5

public class Utils {

    public static String MD5(String md5) {
        try {
            java.security.MessageDigest md = java.security.MessageDigest.getInstance("MD5");
            byte[] array = md.digest(md5.getBytes());
            StringBuffer sb = new StringBuffer();
            for (int i = 0; i < array.length; ++i)
                sb.append(Integer.toHexString((array[i] & 0xFF) | 0x100).substring(1, 3));

            return sb.toString();
        } catch (java.security.NoSuchAlgorithmException e) { }
        return null;
    }

}