一个实现MD5的简洁的java类

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一个实现MD5的简洁的java类 Jagie 原创   更新：2003-11-19 08:34:38  版本: 1.0

<!----> 关键词:md5 由于消息摘要唯一性和不可逆性的特点，所以不失为一种简单的常用的加密手段，比如你可以用md5来加密你的应用中的用户口令。

package cn.tisson.test;import java.security.MessageDigest;/** * <p> * Title: * </p> * <p> * Description: * </p> * <p> * Copyright: Copyright (c) 2003 * </p> * <p> * Company: * </p> *  * @author unascribed * @version 1.0 */public class MD5Test {private final static String[] hexDigits = { "0", "1", "2", "3", "4", "5","6", "7", "8", "9", "a", "b", "c", "d", "e", "f" };/** * 转换字节数组为16进制字串 *  * @param b *            字节数组 * @return 16进制字串 */public static String byteArrayToHexString(byte[] b) {StringBuffer resultSb = new StringBuffer();for (int i = 0; i < b.length; i++) {resultSb.append(byteToHexString(b));}return resultSb.toString();}private static String byteToHexString(byte b) {int n = b;if (n < 0)n = 256 + n;int d1 = n / 16;int d2 = n % 16;return hexDigits[d1] + hexDigits[d2];}public static String MD5Encode(String origin) {String resultString = null;try {resultString = new String(origin);MessageDigest md = MessageDigest.getInstance("MD5");resultString = byteArrayToHexString(md.digest(resultString.getBytes()));} catch (Exception ex) {ex.printStackTrace();}return resultString;}public static void main(String[] args) {System.err.println(MD5Encode("a"));}} 在RFC 1321中，给出了Test suite用来检验你的实现是否正确：

MD5 ("") = d41d8cd98f00b204e9800998ecf8427e
MD5 ("a") = 0cc175b9c0f1b6a831c399e269772661
MD5 ("abc") = 900150983cd24fb0d6963f7d28e17f72
MD5 ("message digest") = f96b697d7cb7938d525a2f31aaf161d0
MD5 ("abcdefghijklmnopqrstuvwxyz") = c3fcd3d76192e4007dfb496cca67e13b


参考资料:《java security handbook》 jamie jaworski