MD5加密工具类

简单的md5加密：
 1 package com.util;
 2 
 3 import java.security.MessageDigest;
 4 import java.security.NoSuchAlgorithmException;
 5 
 6 public class MD5 {
 7     public static String Md5(String plainText) {
 8         String md5=null;
 9         try {
10             MessageDigest md = MessageDigest.getInstance("MD5");
11             md.update(plainText.getBytes());
12             byte b[] = md.digest();
13             int i;
14             StringBuffer buf = new StringBuffer("");
15             for (int offset = 0; offset < b.length; offset++) {
16                 i = b[offset];
17                 if (i < 0)
18                     i += 256;
19                 if (i < 16)
20                     buf.append("0");
21                 buf.append(Integer.toHexString(i));
22             }
23             md5 = buf.toString().substring(8, 24);
24             
25         } catch (NoSuchAlgorithmException e) {
26             e.printStackTrace();
27         }
28         return md5;
29     }
30 }