1 /**
 2  * 核心請求處理類 
 3  * 
 4  */
 5 public class CrazyServlet extends HttpServlet {
 6 
 7     private static final long serialVersionUID = 5021188348833856475L;
 8     @Override
 9     protected void doGet(HttpServletRequest request, HttpServletResponse response)throws ServletException, IOException {
10         // 微信加密簽名  
11         String signature = request.getParameter("signature");  
12         // 時間戳  
13         String timestamp = request.getParameter("timestamp");  
14         // 隨機數  
15         String nonce = request.getParameter("nonce");  
16         // 隨機字串  
17         String echostr = request.getParameter("echostr");  
18         PrintWriter out = response.getWriter();  
19         // 通過檢驗signature對請求進行校驗，若校驗成功則原樣返回echostr，表示接入成功，否則接入失敗  
20         if (SignUtil.checkSignature(signature, timestamp, nonce)) {  
21                 out.print(echostr);  
22         }  
23         out.close();
24         out = null;
25     }

 1 /**
 2  * 請求校驗工具類
 3  */
 4 public class SignUtil {
 5     // 與介面配置資訊中的Token要一致
 6     private static String token = "845C2550903CE6FA54CACDB82EAD4350";
 7 
 8     
 9     public static boolean checkSignature(String signature, String timestamp,
10             String nonce) {
11         //從請求中（也就是微信伺服器傳過來的）拿到的token, timestamp, nonce
12         String[] arr = new String[] { token, timestamp, nonce };
13         // 將token、timestamp、nonce三個引數進行字典序排序
14         sort(arr);
15         StringBuilder content = new StringBuilder();
16         for (int i = 0; i < arr.length; i++) {
17             content.append(arr[i]);
18         }
19         MessageDigest md = null;
20         String tmpStr = null;
21 
22         try {
23             md = MessageDigest.getInstance("SHA-1");
24             // 將三個引數字串拼接成一個字串進行sha1加密
25             byte[] digest = md.digest(content.toString().getBytes());
26             //將位元組陣列轉成字串
27             tmpStr = byteToStr(digest);
28         } catch (NoSuchAlgorithmException e) {
29             e.printStackTrace();
30         }
31 
32         content = null;
33         // 將sha1加密後的字串可與signature對比，標識該請求來源於微信
34         return tmpStr != null ? tmpStr.equals(signature.toUpperCase()) : false;
35     }
36 
37   //將加密後的位元組陣列變成字串
38     private static String byteToStr(byte[] byteArray) {
39         String strDigest = "";
40         for (int i = 0; i < byteArray.length; i++) {
41             strDigest += byteToHexStr(byteArray[i]);
42         }
43         return strDigest;
44     }
45 
46     private static String byteToHexStr(byte mByte) {
47         char[] Digit = { ‘0‘, ‘1‘, ‘2‘, ‘3‘, ‘4‘, ‘5‘, ‘6‘, ‘7‘, ‘8‘, ‘9‘, ‘A‘,
48                 ‘B‘, ‘C‘, ‘D‘, ‘E‘, ‘F‘ };
49         char[] tempArr = new char[2];
50         tempArr[0] = Digit[(mByte >>> 4) & 0X0F];
51         tempArr[1] = Digit[mByte & 0X0F];
52 
53         String s = new String(tempArr);
54         return s;
55     }
56 //用於字典排序
57     public static void sort(String a[]) {
58         for (int i = 0; i < a.length - 1; i++) {
59             for (int j = i + 1; j < a.length; j++) {
60                 if (a[j].compareTo(a[i]) < 0) {
61                     String temp = a[i];
62                     a[i] = a[j];
63                     a[j] = temp;
64                 }
65             }
66         }
67     }
68 }