md5算法代码


package com.bjhj.castest;

import java.security.MessageDigest;

public class myDigest {



public static void main(String[] args) {

myDigest my = new myDigest();

my.testDigest("我的测试信息");

}

public void testDigest(String myinfo) {

try {

MessageDigest alga = MessageDigest.getInstance("MD5");

alga.update(myinfo.getBytes());

byte[] digesta = alga.digest();

System.out.println("本信息摘要是:" + byte2hex(digesta));

// 通过某中方式传给其他人你的信息(myinfo)和摘要(digesta) 对方可以判断是否更改或传输正常

MessageDigest algb = MessageDigest.getInstance("MD5");

algb.update(myinfo.getBytes());

if (MessageDigest.isEqual(digesta, algb.digest())) {

System.out.println("信息检查正常");

} else {

System.out.println("摘要不相同");

}

} catch (java.security.NoSuchAlgorithmException ex) {

System.out.println("非法摘要算法");

}

}

public String byte2hex(byte[] b) // 二行制转字符串

{

String hs = "";

String stmp = "";

for (int n = 0; n < b.length; n++) {

stmp = (Integer.toHexString(b
& 0XFF));

if (stmp.length() == 1)

hs = hs + "0" + stmp;

else

hs = hs + stmp;

if (n < b.length - 1)

hs = hs + ":";

}

return hs.toUpperCase();

}

}