Java security MD5加密算法

利用java.security对字符串进行MD5加密：

 1 import java.security.MessageDigest;
 2 import java.security.NoSuchAlgorithmException;
 3
 4 public class MD5 {
 5     public static final String MD5CODE = "";
 6
 7     private static MessageDigest messageDigest = null;
 8
 9     public static String Encode(final String Source) {
10         return Encode(Source + MD5CODE, null);
11     }
12
13     public static String Encode(final String Source, final String charset) {
14         if (Source == null)
15             return null;
16         if (messageDigest == null) {
17             try {
18                 messageDigest = MessageDigest.getInstance("MD5");
19             } catch (NoSuchAlgorithmException e) {
20                 return null;
21             }
22         }
23         if (charset == null || charset.trim().length() <= 0){
24             messageDigest.update(Source.getBytes());
25             }else {
26             try {
27                 messageDigest.update(Source.getBytes(charset));
28             } catch (Exception e) {
29                 messageDigest.update(Source.getBytes());
30             }
31         }
32         byte[] digesta = messageDigest.digest();
33         return Bytes2Hex(digesta);
34     }
35
36     public static byte[] EncodeBytes(byte[] Source) {
37         if (messageDigest == null) {
38             try {
39                 messageDigest = MessageDigest.getInstance("MD5");
40             } catch (NoSuchAlgorithmException e) {
41                 return null;
42             }
43         }
44         messageDigest.update(Source);
45         byte[] ret = messageDigest.digest();
46         return ret;
47     }
48
49     public static String Bytes2Hex(final byte[] Source) {
50         String hs = "";
51         String stmp = "";
52         for (int n = 0; n < Source.length; n++) {
53             stmp = (java.lang.Integer.toHexString(Source[n] & 0xFF));
54             if (stmp.length() == 1)
55                 hs = hs + "0" + stmp;
56             else
57                 hs = hs + stmp;
58         }
59         return hs;
60     }
61
62     public static void main(String args[]) {
63
64         String str = "123456";
65         String encode = MD5.Encode(str);
66         String encode1 = MD5.Encode(str);
67         String encode2 = MD5.Encode(str);
68         System.out.println("MD5.encode 123456="+encode+"---"+encode1+"---"+encode2);
69
70     }
71 }