做微信公众号的开发者模式时报错，第一个文本接口同美通过，一直报错，帮忙看看，谢谢了

<?xml version="1.0" encoding="UTF-8"?>

<web-app version="2.5" 

	xmlns="http://java.sun.com/xml/ns/javaee" 

	xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" 

	xsi:schemaLocation="http://java.sun.com/xml/ns/javaee 

	http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd">

  

  <servlet>

  	<servlet-name>weixinServlet</servlet-name>

  	<servlet-class>com.zhen.servlet.WeixinServlet</servlet-class>

  	<load-on-startup>1</load-on-startup>

  </servlet>

  

  <servlet-mapping>

  	<servlet-name>weixinServlet</servlet-name>

  	<url-pattern>/WX.do</url-pattern>

  </servlet-mapping>

  

  <welcome-file-list>

    <welcome-file>index.jsp</welcome-file>

  </welcome-file-list>

</web-app>

package com.zhen.servlet;



import java.io.IOException;

import java.io.PrintWriter;

import java.util.HashMap;

import java.util.Map;



import javax.servlet.ServletException;

import javax.servlet.http.HttpServlet;

import javax.servlet.http.HttpServletRequest;

import javax.servlet.http.HttpServletResponse;



import org.dom4j.DocumentException;



import com.zhen.dto.MessageDTO;

import com.zhen.util.CheckUtil;

import com.zhen.util.MessageUtil;



public class WeixinServlet extends HttpServlet {

	@Override

	protected void doGet(HttpServletRequest request, HttpServletResponse response)

			throws ServletException, IOException {

		// TODO Auto-generated method stub

		String signature = request.getParameter("signature");//

		String timestamp = request.getParameter("timestamp");

		String nonce = request.getParameter("nonce");

		String echostr = request.getParameter("echostr");

		

		PrintWriter out = response.getWriter();

		response.setCharacterEncoding("utf-8");

		if (CheckUtil.checkSignature(signature, timestamp, nonce)) {

			out.print(echostr);

		}

	}

	@Override

	protected void doPost(HttpServletRequest request, HttpServletResponse response)

			throws ServletException, IOException {

		// TODO Auto-generated method stub

		request.setCharacterEncoding("utf-8");

		response.setCharacterEncoding("utf-8");

		String result = null;

		MessageDTO messageDTO = new MessageDTO();

		String type = request.getParameter("MsgType");

		Map<String, String> mapone = new HashMap<String, String>();

		PrintWriter out = null;

		

			

		try 

		{

			mapone = MessageUtil.xmlToMap(request);

		} catch (DocumentException e) {

			// TODO Auto-generated catch block

			e.printStackTrace();

		}

		String msgType = mapone.get("MsgType");

		messageDTO.setToUserName(mapone.get("fromUserName"));

		messageDTO.setFromUserName(mapone.get("ToUserName"));

		messageDTO.setCreateTime(mapone.get("createTime"));

		messageDTO.setMsgType(msgType);

		messageDTO.setContent(mapone.get("content"));



		out = response.getWriter();

				

		out.print(result);

	

	}

}

public static Map xmlToMap(HttpServletRequest request) throws IOException, DocumentException {

		Map map = new HashMap();

		SAXReader reader = new SAXReader();

		InputStream ins = request.getInputStream();

	

		Document doc = reader.read(ins);

		Element root = doc.getRootElement();

		List<Element> list = root.elements();

		for(Element e:list){

				map.put(e.getName(), e.getText());

			}

		ins.close();

		

		return map;

	}