服务器的错误日志：

org.dom4j.DocumentException: Error on line 1 of document : Premature end of file. Nested exception: Premature end of file.
at org.dom4j.io.SAXReader.read(SAXReader.java:482)
at org.dom4j.io.SAXReader.read(SAXReader.java:343)
at wechat.controller.TokenController.doPost(TokenController.java:155)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:498)
at org.springframework.web.method.support.InvocableHandlerMethod.doInvoke(InvocableHandlerMethod.java:221)
at org.springframework.web.method.support.InvocableHandlerMethod.invokeForRequest(InvocableHandlerMethod.java:136)
at org.springframework.web.servlet.mvc.method.annotation.ServletInvocableHandlerMethod.invokeAndHandle(ServletInvocableHandlerMethod.java:114)
at org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.invokeHandlerMethod(RequestMappingHandlerAdapter.java:827)
at org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.handleInternal(RequestMappingHandlerAdapter.java:738)
at org.springframework.web.servlet.mvc.method.AbstractHandlerMethodAdapter.handle(AbstractHandlerMethodAdapter.java:85)
at org.springframework.web.servlet.DispatcherServlet.doDispatch(DispatcherServlet.java:963)
at org.springframework.web.servlet.DispatcherServlet.doService(DispatcherServlet.java:897)
at org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:970)
at org.springframework.web.servlet.FrameworkServlet.doGet(FrameworkServlet.java:861)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:622)
at org.springframework.web.servlet.FrameworkServlet.service(FrameworkServlet.java:846)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:729)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:292)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:207)
at org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:52)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:240)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:207)
at org.springframework.web.filter.CharacterEncodingFilter.doFilterInternal(CharacterEncodingFilter.java:197)
at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:240)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:207)
at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:212)
at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:106)
at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:502)
at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:141)
at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:79)
at org.apache.catalina.valves.AbstractAccessLogValve.invoke(AbstractAccessLogValve.java:616)
at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:88)
at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:528)
at org.apache.coyote.http11.AbstractHttp11Processor.process(AbstractHttp11Processor.java:1100)
at org.apache.coyote.AbstractProtocol$AbstractConnectionHandler.process(AbstractProtocol.java:687)
at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.doRun(NioEndpoint.java:1520)
at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.run(NioEndpoint.java:1476)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)
at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61)
at java.lang.Thread.run(Thread.java:745)
Nested exception: 
org.xml.sax.SAXParseException; lineNumber: 1; columnNumber: 1; Premature end of file.
at com.sun.org.apache.xerces.internal.util.ErrorHandlerWrapper.createSAXParseException(ErrorHandlerWrapper.java:203)
at com.sun.org.apache.xerces.internal.util.ErrorHandlerWrapper.fatalError(ErrorHandlerWrapper.java:177)
at com.sun.org.apache.xerces.internal.impl.XMLErrorReporter.reportError(XMLErrorReporter.java:400)
at com.sun.org.apache.xerces.internal.impl.XMLErrorReporter.reportError(XMLErrorReporter.java:327)
at com.sun.org.apache.xerces.internal.impl.XMLScanner.reportFatalError(XMLScanner.java:1472)
at com.sun.org.apache.xerces.internal.impl.XMLDocumentScannerImpl$PrologDriver.next(XMLDocumentScannerImpl.java:1014)
at com.sun.org.apache.xerces.internal.impl.XMLDocumentScannerImpl.next(XMLDocumentScannerImpl.java:602)
at com.sun.org.apache.xerces.internal.impl.XMLNSDocumentScannerImpl.next(XMLNSDocumentScannerImpl.java:112)
at com.sun.org.apache.xerces.internal.impl.XMLDocumentFragmentScannerImpl.scanDocument(XMLDocumentFragmentScannerImpl.java:505)
at com.sun.org.apache.xerces.internal.parsers.XML11Configuration.parse(XML11Configuration.java:841)
at com.sun.org.apache.xerces.internal.parsers.XML11Configuration.parse(XML11Configuration.java:770)
at com.sun.org.apache.xerces.internal.parsers.XMLParser.parse(XMLParser.java:141)
at com.sun.org.apache.xerces.internal.parsers.AbstractSAXParser.parse(AbstractSAXParser.java:1213)
at com.sun.org.apache.xerces.internal.jaxp.SAXParserImpl$JAXPSAXParser.parse(SAXParserImpl.java:643)
at org.dom4j.io.SAXReader.read(SAXReader.java:465)
at org.dom4j.io.SAXReader.read(SAXReader.java:343)
at wechat.controller.TokenController.doPost(TokenController.java:155)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:498)
at org.springframework.web.method.support.InvocableHandlerMethod.doInvoke(InvocableHandlerMethod.java:221)
at org.springframework.web.method.support.InvocableHandlerMethod.invokeForRequest(InvocableHandlerMethod.java:136)
at org.springframework.web.servlet.mvc.method.annotation.ServletInvocableHandlerMethod.invokeAndHandle(ServletInvocableHandlerMethod.java:114)
at org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.invokeHandlerMethod(RequestMappingHandlerAdapter.java:827)
at org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.handleInternal(RequestMappingHandlerAdapter.java:738)
at org.springframework.web.servlet.mvc.method.AbstractHandlerMethodAdapter.handle(AbstractHandlerMethodAdapter.java:85)
at org.springframework.web.servlet.DispatcherServlet.doDispatch(DispatcherServlet.java:963)
at org.springframework.web.servlet.DispatcherServlet.doService(DispatcherServlet.java:897)
at org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:970)
at org.springframework.web.servlet.FrameworkServlet.doGet(FrameworkServlet.java:861)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:622)
at org.springframework.web.servlet.FrameworkServlet.service(FrameworkServlet.java:846)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:729)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:292)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:207)
at org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:52)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:240)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:207)
at org.springframework.web.filter.CharacterEncodingFilter.doFilterInternal(CharacterEncodingFilter.java:197)
at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:240)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:207)
at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:212)
at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:106)
at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:502)
at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:141)
at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:79)
at org.apache.catalina.valves.AbstractAccessLogValve.invoke(AbstractAccessLogValve.java:616)
at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:88)
at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:528)
at org.apache.coyote.http11.AbstractHttp11Processor.process(AbstractHttp11Processor.java:1100)
at org.apache.coyote.AbstractProtocol$AbstractConnectionHandler.process(AbstractProtocol.java:687)
at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.doRun(NioEndpoint.java:1520)
at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.run(NioEndpoint.java:1476)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)
at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61)
at java.lang.Thread.run(Thread.java:745)
Nested exception: org.xml.sax.SAXParseException; lineNumber: 1; columnNumber: 1; Premature end of file.
at com.sun.org.apache.xerces.internal.util.ErrorHandlerWrapper.createSAXParseException(ErrorHandlerWrapper.java:203)
at com.sun.org.apache.xerces.internal.util.ErrorHandlerWrapper.fatalError(ErrorHandlerWrapper.java:177)
at com.sun.org.apache.xerces.internal.impl.XMLErrorReporter.reportError(XMLErrorReporter.java:400)
at com.sun.org.apache.xerces.internal.impl.XMLErrorReporter.reportError(XMLErrorReporter.java:327)
at com.sun.org.apache.xerces.internal.impl.XMLScanner.reportFatalError(XMLScanner.java:1472)
at com.sun.org.apache.xerces.internal.impl.XMLDocumentScannerImpl$PrologDriver.next(XMLDocumentScannerImpl.java:1014)
at com.sun.org.apache.xerces.internal.impl.XMLDocumentScannerImpl.next(XMLDocumentScannerImpl.java:602)
at com.sun.org.apache.xerces.internal.impl.XMLNSDocumentScannerImpl.next(XMLNSDocumentScannerImpl.java:112)
at com.sun.org.apache.xerces.internal.impl.XMLDocumentFragmentScannerImpl.scanDocument(XMLDocumentFragmentScannerImpl.java:505)
at com.sun.org.apache.xerces.internal.parsers.XML11Configuration.parse(XML11Configuration.java:841)
at com.sun.org.apache.xerces.internal.parsers.XML11Configuration.parse(XML11Configuration.java:770)
at com.sun.org.apache.xerces.internal.parsers.XMLParser.parse(XMLParser.java:141)
at com.sun.org.apache.xerces.internal.parsers.AbstractSAXParser.parse(AbstractSAXParser.java:1213)
at com.sun.org.apache.xerces.internal.jaxp.SAXParserImpl$JAXPSAXParser.parse(SAXParserImpl.java:643)
at org.dom4j.io.SAXReader.read(SAXReader.java:465)
at org.dom4j.io.SAXReader.read(SAXReader.java:343)
at wechat.controller.TokenController.doPost(TokenController.java:155)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:498)
at org.springframework.web.method.support.InvocableHandlerMethod.doInvoke(InvocableHandlerMethod.java:221)
at org.springframework.web.method.support.InvocableHandlerMethod.invokeForRequest(InvocableHandlerMethod.java:136)
at org.springframework.web.servlet.mvc.method.annotation.ServletInvocableHandlerMethod.invokeAndHandle(ServletInvocableHandlerMethod.java:114)
at org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.invokeHandlerMethod(RequestMappingHandlerAdapter.java:827)
at org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.handleInternal(RequestMappingHandlerAdapter.java:738)
at org.springframework.web.servlet.mvc.method.AbstractHandlerMethodAdapter.handle(AbstractHandlerMethodAdapter.java:85)
at org.springframework.web.servlet.DispatcherServlet.doDispatch(DispatcherServlet.java:963)
at org.springframework.web.servlet.DispatcherServlet.doService(DispatcherServlet.java:897)
at org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:970)
at org.springframework.web.servlet.FrameworkServlet.doGet(FrameworkServlet.java:861)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:622)
at org.springframework.web.servlet.FrameworkServlet.service(FrameworkServlet.java:846)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:729)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:292)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:207)
at org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:52)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:240)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:207)
at org.springframework.web.filter.CharacterEncodingFilter.doFilterInternal(CharacterEncodingFilter.java:197)
at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:240)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:207)
at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:212)
at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:106)
at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:502)
at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:141)
at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:79)
at org.apache.catalina.valves.AbstractAccessLogValve.invoke(AbstractAccessLogValve.java:616)
at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:88)
at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:528)
at org.apache.coyote.http11.AbstractHttp11Processor.process(AbstractHttp11Processor.java:1100)
at org.apache.coyote.AbstractProtocol$AbstractConnectionHandler.process(AbstractProtocol.java:687)
at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.doRun(NioEndpoint.java:1520)
at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.run(NioEndpoint.java:1476)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)
at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61)
at java.lang.Thread.run(Thread.java:745)

代码：

package wechat.controller;

import java.io.BufferedReader;
import java.io.FileInputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.PrintWriter;
import java.security.MessageDigest;
import java.security.NoSuchAlgorithmException;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.Date;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import java.util.Set;

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

import org.dom4j.Document;
import org.dom4j.DocumentException;
import org.dom4j.DocumentHelper;
import org.dom4j.Element;
import org.dom4j.io.SAXReader;
import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.ResponseBody;

import com.thoughtworks.xstream.XStream;

import wechat.model.Article;
import wechat.model.PicAndTextMsg;
import wechat.model.TextMsg;
/**
 * 
 * @author 
 * 
 * 
 * 
 * 
 */

@Controller
@RequestMapping("/token")
public class TokenController {
     String TAG = "token";
      /*
       * 第二步：验证服务器地址的有效性 开发者提交信息后，微信服务器将发送GET请求到填写的服务器地址URL上，
       * GET请求携带四个参数：signature、timestamp、nonce、echostr
       * 开发者通过检验signature对请求进行校验（下面有校验方式）。 若确认此次GET请求来自微信服务器，请原样返回echostr参数内容，
       * 则接入生效， 成为开发者成功，否则接入失败。
       * 
       * 加密/校验流程如下： 1. 将token、timestamp、nonce三个参数进行字典序排序 2.
       * 将三个参数字符串拼接成一个字符串进行sha1加密 3. 开发者获得加密后的字符串可与signature对比，标识该请求来源于微信
       */
      /*
       * 字典排序（lexicographical
       * order）是一种对于随机变量形成序列的排序方法。其方法是，按照字母顺序，或者数字小大顺序，由小到大的形成序列。
       */
      protected void doGet(HttpServletRequest req, HttpServletResponse resp)
          throws ServletException, IOException {
     
        // 设置编码
        req.setCharacterEncoding("utf-8");
        resp.setContentType("html/text;charset=utf-8");
        resp.setCharacterEncoding("utf-8");
        // 获取输出流
        PrintWriter printWriter = resp.getWriter();
     
        // 设置一个全局的token,开发者自己设置。api这样解释：Token可由开发者可以任意填写，
        // 用作生成签名（该Token会和接口URL中包含的Token进行比对，从而验证安全性）
        String token = "xxxxxx";
        // 根据api说明，获取上述四个参数
        String signature = req.getParameter("signature");
        String timestamp = req.getParameter("timestamp");
        String nonce = req.getParameter("nonce");
        String echostr = req.getParameter("echostr");
       /* PrintWriter out = resp.getWriter();  
           out.print(echostr);*/

        // // temp:临时打印，观看返回参数情况
        // System.out.println(TAG + ":signature:" + signature + ",timestamp:"
        // + timestamp + ",nonce:" + nonce + ",echostr:" + echostr);
        // 根据api所说的“加密/校验流程”进行接入。共计三步
     
        // 第一步:将token、timestamp、nonce三个参数进行字典序排序
        String[] parms = new String[] { token, timestamp, nonce };// 将需要字典序排列的字符串放到数组中
        Arrays.sort(parms);// 按照api要求进行字典序排序
        // 第二步:将三个参数字符串拼接成一个字符串进行sha1加密
        // 拼接字符串
        String parmsString = "";// 注意，此处不能=null。
        for (int i = 0; i < parms.length; i++) {
          parmsString += parms[i];
        }
        // sha1加密
        String mParms = null;// 加密后的结果
        MessageDigest digest = null;
        try {
          digest = java.security.MessageDigest.getInstance("SHA");
        } catch (NoSuchAlgorithmException e) {
          // TODO Auto-generated catch block
          e.printStackTrace();
        }
        digest.update(parmsString.getBytes());
        byte messageDigest[] = digest.digest();
        // Create Hex String
        StringBuffer hexString = new StringBuffer();
        // 字节数组转换为 十六进制 数
        for (int i = 0; i < messageDigest.length; i++) {
          String shaHex = Integer.toHexString(messageDigest[i] & 0xFF);
          if (shaHex.length() < 2) {
            hexString.append(0);
          }
          hexString.append(shaHex);
        }
        mParms = hexString.toString();// 加密结果
     
        /*
         * api要求： 若确认此次GET请求来自微信服务器，请原样返回echostr参数内容， 则接入生效， 成为开发者成功，否则接入失败。
         */
        // 第三步： 开发者获得加密后的字符串可与signature对比，标识该请求来源于微信接入成功。
        //System.out.println(TAG + ":" + mParms + "---->" + signature);
        if (mParms.equals(signature)) {
          // System.out.println(TAG + ":" + mParms + "---->" + signature);
          printWriter.write(echostr);
        } else {
          // 接入失败,不用回写
          // System.out.println(TAG + "接入失败");
        }
      }
     
      @RequestMapping("/doPost")
      @ResponseBody
      protected void doPost(HttpServletRequest req, HttpServletResponse resp)
                throws ServletException, IOException {
            // 设置编码
            req.setCharacterEncoding("utf-8");
            resp.setContentType("html/text;charset=utf-8");
            resp.setCharacterEncoding("utf-8");

            /*
             * 该部分我们获取用户发送的信息，并且解析成<K,V>的形式进行显示
             */
            // 解析用户发送过来的信息
            InputStream is = req.getInputStream();// 拿取请求流
            // 将解析结果存储在HashMap中
            Map<String, String> map = new HashMap<String, String>();
            // 解析xml，将获取到的返回结果xml进行解析成我们习惯的文字信息
            SAXReader reader = new SAXReader();// 第三方jar:dom4j【百度：saxreader解析xml】
            Document document = null;
            try {
                document = reader.read(is);//错误日志上的155行
            } catch (DocumentException e1) {
                // TODO Auto-generated catch block
                e1.printStackTrace();
            }
            
            
            // 得到xml根元素
            Element root = document.getRootElement();
            // 得到根元素的所有子节点
            List<Element> elementList = root.elements();

            // 遍历所有子节点
            for (Element e : elementList)
                map.put(e.getName(), e.getText());

            // 测试输出
            Set<String> keySet = map.keySet();
            // 测试输出解析后用户发过来的信息
           // System.out.println(TAG + "：解析用户发送过来的信息开始");
            for (String key : keySet) {
               // System.out.println(key + ":" + map.get(key));
            }
            //System.out.println(TAG + "：解析用户发送过来的信息结束");

            /*
             * 该部分我们尝试按照文档的要求格式给用户回复文本信息、图文消息。重点：按照文档要求构造需要的参数。特别注意：参数区分大小写。
             */

            // //实例1：发送普通文本消息,请查看文档关于“回复文本消息”的xml格式
            //
            // // 第一步：按照回复文本信息构造需要的参数
            /* TextMsg textMsg = new TextMsg();
             textMsg.setToUserName(map.get("FromUserName"));// 发送和接收信息“User”刚好相反
             textMsg.setFromUserName(map.get("ToUserName"));
             textMsg.setCreateTime(new Date().getTime());// 消息创建时间 （整型）
             textMsg.setMsgType("text");// 文本类型消息
             textMsg.setContent("我是服务器回复给用户的信息");
            //
            // // // 第二步，将构造的信息转化为微信识别的xml格式【百度：xstream bean转xml】
             XStream xStream = new XStream();
             xStream.alias("xml", textMsg.getClass());
             String textMsg2Xml = xStream.toXML(textMsg);
             System.out.println(textMsg2Xml);
            //
            // // // 第三步，发送xml的格式信息给微信服务器，服务器转发给用户
             PrintWriter printWriter = resp.getWriter();
             printWriter.print(textMsg2Xml);*/

           
            
            
            // //实例2，发送图文消息。请查看文档关于“回复图文消息”的xml格式

            // 第一步：按照回复图文信息构造需要的参数
            List<Article> articles = new ArrayList<Article>();
            Article a = new Article();
            a.setTitle("xxxxxxx");
            a.setUrl("xxxxxxx");// 该地址是点击图片跳转后
            a.setPicUrl("xxxxxx");// 该地址是一个有效的图片地址
            a.setDescription("xxxxxx");
            articles.add(a);
            PicAndTextMsg picAndTextMsg = new PicAndTextMsg();
            picAndTextMsg.setToUserName(map.get("FromUserName"));// 发送和接收信息“User”刚好相反
            picAndTextMsg.setFromUserName(map.get("ToUserName"));
            picAndTextMsg.setCreateTime(new Date().getTime());// 消息创建时间 （整型）
            picAndTextMsg.setMsgType("news");// 图文类型消息
            picAndTextMsg.setArticleCount(1);
            picAndTextMsg.setArticles(articles);
            // 第二步，将构造的信息转化为微信识别的xml格式【百度：xstream bean转xml】
            XStream xStream = new XStream();
            xStream.alias("xml", picAndTextMsg.getClass());
            xStream.alias("item", a.getClass());
            String picAndTextMsg2Xml = xStream.toXML(picAndTextMsg);
         //   System.out.println(picAndTextMsg2Xml);
            // 第三步，发送xml的格式信息给微信服务器，服务器转发给用户
            PrintWriter printWriter = resp.getWriter();
            printWriter.print(picAndTextMsg2Xml);
        }
    }