Java微信二次开发（一） Java微信请求验证功能

package com.wtz.service;import java.io.IOException;import java.io.PrintWriter;import javax.servlet.ServletException;import javax.servlet.http.HttpServlet;import javax.servlet.http.HttpServletRequest;import javax.servlet.http.HttpServletResponse;import com.wtz.util.ValidationUtil;public class LoginServlet extends HttpServlet { @Override protected void doGet(HttpServletRequest request, HttpServletResponse response)   throws ServletException, IOException {  System.out.println("get请求。。。。。。");    //1.获得微信签名的加密字符串  String signature = request.getParameter("signature");    //2.获得时间戳信息  String timestamp = request.getParameter("timestamp");     //3.获得随机数  String nonce = request.getParameter("nonce");    //4.获得随机字符串  String echostr = request.getParameter("echostr");    System.out.println("获得微信签名的加密字符串："+signature);  System.out.println("获得时间戳信息："+timestamp);  System.out.println("获得随机数："+nonce);  System.out.println("获得随机字符串："+echostr);    PrintWriter out = response.getWriter();    //验证请求确认成功原样返回echostr参数内容，则接入生效，成为开发者成功，否则失败  if(ValidationUtil.checkSignature(signature, timestamp, nonce)){   out.print(echostr);  }    out.close();  out = null; }}