Md5.java

/*
 * Copyright (c) 2013, Rainbow and/or its affiliates. All rights reserved.
 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
 *
 * This code is free software;Designed and Developed mainly by many Chinese 
 * opensource volunteers. you can redistribute it and/or modify it under the 
 * terms of the GNU General Public License version 2 only, as published by the
 * Free Software Foundation.
 *
 * This code is distributed in the hope that it will be useful, but WITHOUT
 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
 * version 2 for more details (a copy is included in the LICENSE file that
 * accompanied this code).
 *
 * You should have received a copy of the GNU General Public License version
 * 2 along with this work; if not, write to the Free Software Foundation,
 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
 * 
 * Any questions about this component can be directed to it's project Web address 
 * http://code.taobao.org/svn/rainbow/trunk
 *
 */
package org.hx.rainbow.common.security.md5;

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

public class Md5 {
	private volatile static Md5 md5 = null;
	
	private Md5(){};
	
	public static Md5  getInstance(){
		if(md5 == null){
			synchronized (Md5.class) {
				if(md5 == null){
					md5 = new Md5();
				}
			}
		}
		return md5;
	}

	public String encrypt(String value) {
		try {
			char hexDigits[] = { '0', '1', '2', '3', '4', '5', '6', '7', '8', '9',
					'a', 'b', 'c', 'd', 'e', 'f' };
				byte[] strTemp = value.getBytes();
				MessageDigest mdTemp = MessageDigest.getInstance("MD5");
				mdTemp.update(strTemp);
				byte[] md = mdTemp.digest();
				int j = md.length;
				char str[] = new char[j * 2];
				int k = 0;
				for (int i = 0; i < j; i++) {
					byte byte0 = md[i];
					str[k++] = hexDigits[byte0 >>> 4 & 0xf];
					str[k++] = hexDigits[byte0 & 0xf];
				}
				return new String(str);
		} catch (NoSuchAlgorithmException e) {
			e.printStackTrace();
			return "";
		}
	}
	
	public static void main(String[] args) {
		System.out.println(Md5.getInstance().encrypt("password"));
	}


}