1 package test.md5;
2
3 import java.security.MessageDigest;
4
5 public class MD5Util {
6 public final static String MD5(String s) {
7 char hexDigits[]={'0','1','2','3','4','5','6','7','8','9','A','B','C','D','E','F'};
8
9 try {
10 byte[] btInput = s.getBytes();
11 // 获得MD5摘要算法的 MessageDigest 对象
12 MessageDigest mdInst = MessageDigest.getInstance("MD5");
13 // 使用指定的字节更新摘要
14 mdInst.update(btInput);
15 // 获得密文
16 byte[] md = mdInst.digest();
17 // 把密文转换成十六进制的字符串形式
18 int j = md.length;
19 char str[] = new char[j * 2];
20 int k = 0;
21 for (int i = 0; i < j; i++) {
22 byte byte0 = md[i];
23 str[k++] = hexDigits[byte0 >>> 4 & 0xf];
24 str[k++] = hexDigits[byte0 & 0xf];
25 }
26 return new String(str);
27 } catch (Exception e) {
28 e.printStackTrace();
29 return null;
30 }
31 }
32
33 public static void main(String[] args) {
34 System.out.println(MD5Util.MD5("20121221"));
35 System.out.println(MD5Util.MD5("加密"));
36 }
37 }
