Java MessageDigest md5 hash

import java.security.MessageDigest;
import java.security.NoSuchAlgorithmException;

public class Main {
    public static void main(String[] argv) throws Exception {
        String s = "demo2s.com";
        System.out.println(md5(s));
    }/*from   ww  w .  j  a  v  a  2s  .  com*/

    private static final char HEX_DIGITS[] = { '0', '1', '2', '3', '4', '5', '6', '7', '8', '9', 'A', 'B', 'C', 'D',
            'E', 'F' };

    public static String md5(String s) {
        try {
            MessageDigest digest = java.security.MessageDigest.getInstance("MD5");
            digest.update(s.getBytes());
            byte messageDigest[] = digest.digest();
            return toHexString(messageDigest);
        } catch (NoSuchAlgorithmException e) {
            e.printStackTrace();
        }
        return "";
    }

    private static String toHexString(byte[] b) {
        StringBuilder sb = new StringBuilder(b.length * 2);
        for (int i = 0; i < b.length; i++) {
            sb.append(HEX_DIGITS[(b[i] & 0xf0) >>> 4]);
            sb.append(HEX_DIGITS[b[i] & 0x0f]);
        }
        return sb.toString();
    }
}