Java實現MD5加密

package com.lichen.test;

import java.security.MessageDigest;    
public class Test_MD5{    
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();    
     //使用MD5建立MessageDigest對象    
     MessageDigest mdTemp = MessageDigest.getInstance( "MD5"); //MD5也能夠換成SHA-1
     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 b = md[i];    
         //System.out.println((int)b);    
         //將沒個數(int)b進行雙字節加密    
        str[k++] = hexDigits[b >> 4 & 0xf];    
        str[k++] = hexDigits[b & 0xf];    
     }    
     return new String(str);    
    } catch (Exception e) { return null;}    
    }    
     //測試    
public static void main(String[] args) {    
    System.out.println( "MD5加密後：\n"+Test_MD5.MD5( "嚄"));     }     }