package com.base.action;

import java.io.PrintWriter;
import java.security.MessageDigest;
import java.security.NoSuchAlgorithmException;
import java.util.Arrays;
import java.util.Enumeration;

import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

import org.apache.log4j.Logger;
import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.RequestMapping;

@RequestMapping("/wechat")
@Controller
public class WechatController {
 private static Logger logger = Logger.getLogger(WechatController.class);
  
 private static String token = "xuejp";
 
 @RequestMapping(value = "/wx.do")
 public void get(HttpServletRequest request, HttpServletResponse response) throws Exception {
  System.out.println("========WechatController========= ");
  logger.info("-----来自微信的请求----");
 
  Enumeration pNames = request.getParameterNames();
  while (pNames.hasMoreElements()) {
   String name = (String) pNames.nextElement();
   String value = request.getParameter(name);
   //查看微信的请求都带了哪些参数
   String log = "name =" + name + "  value =" + value;
   logger.error(log);
  }
 
  String signature = request.getParameter("signature");/// 微信加密签名
  String timestamp = request.getParameter("timestamp");/// 时间戳
  String nonce = request.getParameter("nonce"); /// 随机数
  String echostr = request.getParameter("echostr"); // 随机字符串
  PrintWriter out = response.getWriter();
 
  if (checkSignature(signature, timestamp, nonce)) {
   out.print(echostr);
  }
 
  out.print(token);
 
  out.close();
  out = null;
 
 }
 
 /**
  * 校验签名
  */
 public static boolean checkSignature(String signature, String timestamp, String nonce) {
  System.out.println("signature:" + signature + "timestamp:" + timestamp + "nonc:" + nonce);
  String[] arr = new String[] { token, timestamp, nonce };
  // 将token、timestamp、nonce三个参数进行字典序排序
  Arrays.sort(arr);
  StringBuilder content = new StringBuilder();
  for (int i = 0; i < arr.length; i++) {
   content.append(arr[i]);
  }
  MessageDigest md = null;
  String tmpStr = null;
 
  try {
   md = MessageDigest.getInstance("SHA-1");
   // 将三个参数字符串拼接成一个字符串进行sha1加密
   byte[] digest = md.digest(content.toString().getBytes());
   tmpStr = byteToStr(digest);
  } catch (NoSuchAlgorithmException e) {
   e.printStackTrace();
  }
 
  content = null;
  // 将sha1加密后的字符串可与signature对比，标识该请求来源于微信
  System.out.println(tmpStr.equals(signature.toUpperCase()));
  return tmpStr != null ? tmpStr.equals(signature.toUpperCase()) : false;
 }
 
 /**
  * 将字节数组转换为十六进制字符串
  * 
  * @param byteArray
  * @return
  */
 private static String byteToStr(byte[] byteArray) {
  String strDigest = "";
  for (int i = 0; i < byteArray.length; i++) {
   strDigest += byteToHexStr(byteArray[i]);
  }
  return strDigest;
 }
 
 /**
  * 将字节转换为十六进制字符串
  * 
  * @param mByte
  * @return
  */
 private static String byteToHexStr(byte mByte) {
  char[] Digit = { '0', '1', '2', '3', '4', '5', '6', '7', '8', '9', 'A', 'B', 'C', 'D', 'E', 'F' };
  char[] tempArr = new char[2];
  tempArr[0] = Digit[(mByte >>> 4) & 0X0F];
  tempArr[1] = Digit[mByte & 0X0F];
 
  String s = new String(tempArr);
  return s;
 }
}