MD5签名方法

 1     /**
 2      * md5签名
 3      * @param plainText 要签名的字符串
 4      * @param enc 要编译的格式 gbk；utf-8
 5      * @return
 6      */
 7     public static String MD5(String plainText,String enc) {
 8         String re_md5 = new String();
 9         try {
10             MessageDigest md = MessageDigest.getInstance("MD5");
11             md.update(plainText.getBytes(enc));
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             re_md5 = buf.toString();
24         } catch (Exception e) {
25             e.printStackTrace();
26         }
27         return re_md5;
28         
29 
30     }