JAVA 的MD5加密算法

import java.security.*; 
 
import java.security.spec.*; 
 

class MD5_Test{ 
 

public final static String MD5(String s){ 
 
char hexDigits[] = { 
 
'0', '1', '2', '3', '4', '5', '6', '7', '8', '9', 'a', 'b', 'c', 'd', 
 
'e', 'f'}; 
 
try { 
 
byte[] strTemp = s.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
 ; 
str[k++] = hexDigits[byte0 >>> 4 & 0xf]; 
str[k++] = hexDigits[byte0 & 0xf]; 
} 
return new String(str); 
} 
catch (Exception e){ 
return null; 
} 
} 
public static void main(String[] args){ 
//MD5_Test aa = new MD5_Test(); 

System.out.print(MD5_Test.MD5("XX")); 
}