MD5加密解密2

import java.security.MessageDigest;

/**

* 采用MD5加密解密

* @author tfq

* @datetime 2011-10-13

*/

public class MD5UtilTest {

/***

* MD5加码 生成32位md5码

*/

public static String string2MD5(String inStr){

MessageDigest md5 = null;

try{

md5 = MessageDigest.getInstance("MD5");

}catch (Exception e){

System.out.println(e.toString());

e.printStackTrace();

return "";

}

char[] charArray = inStr.toCharArray();

byte[] byteArray = new byte[charArray.length];

for (int i = 0; i < charArray.length; i++)

byteArray[i] = (byte) charArray[i];

byte[] md5Bytes = md5.digest(byteArray);

StringBuffer hexValue = new StringBuffer();

for (int i = 0; i < md5Bytes.length; i++){

int val = ((int) md5Bytes[i]) & 0xff;

if (val < 16)

hexValue.append("0");

hexValue.append(Integer.toHexString(val));

}

return hexValue.toString();

}

/**

* 加密解密算法 执行一次加密，两次解密

*/

public static String convertMD5(String inStr){

char[] a = inStr.toCharArray();

for (int i = 0; i < a.length; i++){

a[i] = (char) (a[i] ^ 't');

}

String s = new String(a);

return s;

}

// 测试主函数

public static void main(String args[]) {

String s = new String("tangfuqiang");

System.out.println("原始：" + s);

System.out.println("MD5后：" + string2MD5(s));

System.out.println("加密的：" + convertMD5(s));

System.out.println("解密的：" + convertMD5(convertMD5(s)));

}

}