MD5 hash工具类

public class MD5Utils {
    static class Holder {
        private static MessageDigest MD = null;

        static {
            try {
                MD = MessageDigest.getInstance("MD5");
            } catch (NoSuchAlgorithmException e) {
                e.printStackTrace();
            }
        }
    }

    public static String hash(String str) {
        Holder.MD.update(str.getBytes());
        return new BigInteger(1, Holder.MD.digest()).toString(16);


    }

    public static void main(String[] args) {
        System.out.println(hash("abc"));
    }
}