MD5加密

 1 import java.security.MessageDigest;
 2 
 3 /**
 4  * md5加密 <功能详细描述>
 5  * 
 6  * @author wanglei
 7  * @version [版本号, Feb 28, 2011]
 8  * @see [相关类/方法]
 9  * @since WihomeV100R001C02LGDM05
10 */
11 public class Md5Util
12 {
13     private static final String[] HEXDIGITS = {"0", "1", "2", "3", "4", "5", "6", "7", "8", "9", "a", "b", "c", "d",
14             "e", "f"};
15 
16     private static final int NUM256 = 256;
17 
18     private static final int NUM16 = 16;
19 
20     /**
21      * 对字符串进行MD5加密 <功能详细描述>
22      * 
23      * @param originString String
24      * @return String
25      * @see [类、类#方法、类#成员]
26 */
27     public static String generatePassword(String originString)
28     {
29         if (originString != null)
30         {
31             try
32             {
33                 MessageDigest md = MessageDigest.getInstance("MD5");
34                 // 使用指定的字节数组对摘要进行最后更新，然后完成摘要计算
35                 byte[] results = md.digest(originString.getBytes());
36                 // 将得到的字节数组变成字符串返回
37                 String resultString = byteArrayToHexString(results);
38                 return resultString;
39             }
40             catch (Exception ex)
41             {
42                 ex.printStackTrace();
43             }
44         }
45         return null;
46     }
47 
48     private static String byteArrayToHexString(byte[] b)
49     {
50         StringBuffer resultSb = new StringBuffer();
51         for (int i = 0; i < b.length; i++)
52         {
53             resultSb.append(byteToHexString(b[i]));
54         }
55         return resultSb.toString();
56     }
57 
58     /**
59      * 将一个字节转化成十六进制形式的字符串 <功能详细描述>
60      * 
61      * @param b byte
62      * @return String
63      * @see [类、类#方法、类#成员]
64 */
65     private static String byteToHexString(byte b)
66     {
67         int n = b;
68         if (n < 0)
69         {
70             n = NUM256 + n;
71         }
72         int d1 = n / NUM16;
73         int d2 = n % NUM16;
74         return HEXDIGITS[d1] + HEXDIGITS[d2];
75     }
76 }