微信例子

package com.weixin.servlet;

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.OutputStream;

import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
//url处可以填写：http://服务器地址/项目名/weixin.do

public class TestServlet extends HttpServlet {
    /** 
     * The doGet method of the servlet. <br> 
     *  
     * This method is called when a form has its tag value method equals to get. 
     *  
     * @param request 
     *            the request send by the client to the server 
     * @param response 
     *            the response send by the server to the client 
     * @throws ServletException 
     *             if an error occurred 
     * @throws IOException 
     *             if an error occurred 
     */  
    public void doGet(HttpServletRequest request, HttpServletResponse response)  
            throws ServletException, IOException {  
        request.setCharacterEncoding("UTF-8");  
        response.setCharacterEncoding("UTF-8");  
  
        /** 读取接收到的xml消息 */  
        StringBuffer sb = new StringBuffer();  
        InputStream is = request.getInputStream();  
        InputStreamReader isr = new InputStreamReader(is, "UTF-8");  
        BufferedReader br = new BufferedReader(isr);  
        String s = "";  
        while ((s = br.readLine()) != null) {  
            sb.append(s);  
        }  
        String xml = sb.toString(); //次即为接收到微信端发送过来的xml数据  
  
        String result = "";  
        /** 判断是否是微信接入激活验证，只有首次接入验证时才会收到echostr参数，此时需要把它直接返回 */  
        String echostr = request.getParameter("echostr");  
        if (echostr != null && echostr.length() > 1) {  
            result = echostr;  
        } else {  
            //正常的微信处理流程  
            result = new Process().processMag(xml);  
        }  
  
        try {  
            OutputStream os = response.getOutputStream();  
            os.write(result.getBytes("UTF-8"));  //返回给用户
            os.flush();  
            os.close();  
        } catch (Exception e) {  
            e.printStackTrace();  
        }  
    }  
    
    
    /** 
     * The doPost method of the servlet. <br> 
     *  
     * This method is called when a form has its tag value method equals to 
     * post. 
     *  
     * @param request 
     *            the request send by the client to the server 
     * @param response 
     *            the response send by the server to the client 
     * @throws ServletException 
     *             if an error occurred 
     * @throws IOException 
     *             if an error occurred 
     */  
    public void doPost(HttpServletRequest request, HttpServletResponse response)  
            throws ServletException, IOException {  
        doGet(request, response);  //即都是调用doGet方法
    }  
  

}

1.1 在登录微信官方平台之后，开启开发者模式，此时需要我们填写url和token，所谓url就是我们自己服务器的接口，用WechatServlet.java来实现，相关解释已经在注释中说明，代码如上：

1.2 相应的web.xml配置信息如下，在生成WechatServlet.java的同时，可自动生成web.xml中的配置。前面所提到的url处可以填写例如：http;//服务器地址/项目名/wechat.do

<?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">
  <display-name></display-name>    
  <welcome-file-list>
       <!-- Weixin servlet -->
  <servlet>
  <servlet-name>weixinTest2</servlet-name>
  <servlet-class>com.weixin.servlet.TestServlet</servlet-class>
  </servlet>
  <servlet-mapping>
  <servlet-name>weixinTest2</servlet-name>
  <url-pattern>/weixin.do</url-pattern>
  </servlet-mapping>
    <welcome-file>index.jsp</welcome-file>
  </welcome-file-list>
</web-app>

package com.weixin.servlet;

public class Process {
    /** 
     * 解析处理xml、获取智能回复结果（通过图灵机器人api接口） 
     * @param xml 接收到的微信数据 
     * @return  最终的解析结果（xml格式数据） 
     */  
    public String processMag(String xml){  
        /** 解析xml数据 */  
        ReceiveXmlEntity xmlEntity = new ReceiveXmlProcess().getMsgEntity(xml); //用到了反射机制 
          
        /** 以文本消息为例，调用图灵机器人api接口，获取回复内容 */  
        String result = "";  
        if("text".endsWith(xmlEntity.getMsgType())){//如果是文本信息  
            //result = new TulingApiProcess().getTulingResult(xmlEntity.getContent());  
            result = "恭喜你，测试通过了！········";
        }  
          
        /** 此时，如果用户输入的是“你好”，在经过上面的过程之后，result为“你也好”类似的内容  
         *  因为最终回复给微信的也是xml格式的数据，所有需要将其封装为文本类型返回消息 
         * */
        //即拼接返回的xml
        result = new FormatXmlProcess().formatXmlAnswer(xmlEntity.getFromUserName(), xmlEntity.getToUserName(), result);  
          
        return result;  
    }  

}

package com.weixin.servlet;

import java.lang.reflect.Field;
import java.lang.reflect.Method;
import java.util.Iterator;

import org.dom4j.Document;
import org.dom4j.DocumentHelper;
import org.dom4j.Element;


public class ReceiveXmlProcess {
    /** 
     * 解析微信xml消息 
     * @param strXml 
     * @return 
     */  
    public ReceiveXmlEntity getMsgEntity(String strXml){  
        ReceiveXmlEntity msg = null;  
        try {  
            if (strXml.length() <= 0 || strXml == null)  
                return null;  
               
            // 将字符串转化为XML文档对象  
            Document document = DocumentHelper.parseText(strXml);  
            // 获得文档的根节点  
            Element root = document.getRootElement();  
            // 遍历根节点下所有子节点  
            Iterator<?> iter = root.elementIterator();  
              
            // 遍历所有结点  
            msg = new ReceiveXmlEntity();  
            //利用反射机制，调用set方法  
            //获取该实体的元类型  
            Class<?> c = Class.forName("demo.entity.ReceiveXmlEntity");  
            msg = (ReceiveXmlEntity)c.newInstance();//创建这个实体的对象  
              
            while(iter.hasNext()){  
                Element ele = (Element)iter.next();  
                //获取set方法中的参数字段（实体类的属性）  
                Field field = c.getDeclaredField(ele.getName());  
                //获取set方法，field.getType())获取它的参数数据类型  
                Method method = c.getDeclaredMethod("set"+ele.getName(), field.getType());  
                //调用set方法  
                method.invoke(msg, ele.getText());  
            }  
        } catch (Exception e) {  
            // TODO: handle exception  
            System.out.println("xml 格式异常: "+ strXml);  
            e.printStackTrace();  
        }  
        return msg;  
    }  

}

package com.weixin.servlet;

import java.util.Date;

public class FormatXmlProcess {
    /** 
     * 封装文字类的返回消息 
     * @param to 
     * @param from 
     * @param content 
     * @return 
     */  
    public String formatXmlAnswer(String to, String from, String content) {  
        StringBuffer sb = new StringBuffer();  
        Date date = new Date();  
        sb.append("<xml><ToUserName><![CDATA[");  
        sb.append(to);  
        sb.append("]]></ToUserName><FromUserName><![CDATA[");  
        sb.append(from);  
        sb.append("]]></FromUserName><CreateTime>");  
        sb.append(date.getTime());  
        sb.append("</CreateTime><MsgType><![CDATA[text]]></MsgType><Content><![CDATA[");  
        sb.append(content);  
        sb.append("]]></Content><FuncFlag>0</FuncFlag></xml>");  
        return sb.toString();  
    }  

}

调用接口，用之前需要注册

package com.weixin.servlet;

import java.io.IOException;
import java.io.UnsupportedEncodingException;
import java.net.URLEncoder;

import org.json.JSONObject;

//没有用上····ljq
public class TulingApiProcess {
    /** 
     * 调用图灵机器人api接口，获取智能回复内容，解析获取自己所需结果 
     * @param content 
     * @return 
     */  
    public String getTulingResult(String content){  
        /** 此处为图灵api接口，参数key需要自己去注册申请，先以11111111代替 */  
     /*   String apiUrl = "http://www.tuling123.com/openapi/api?key=11111111&info=";  
        String param = "";  
        try {  
            param = apiUrl+URLEncoder.encode(content,"utf-8");  
        } catch (UnsupportedEncodingException e1) {  
            // TODO Auto-generated catch block  
            e1.printStackTrace();  
        } //将参数转为url编码  
          
        *//** 发送httpget请求 *//*  
        HttpGet request = new HttpGet(param);  
        String result = "";  
        try {  
            HttpResponse response = HttpClients.createDefault().execute(request);  
            if(response.getStatusLine().getStatusCode()==200){  
                result = EntityUtils.toString(response.getEntity());  
            }  
        } catch (ClientProtocolException e) {  
            e.printStackTrace();  
        } catch (IOException e) {  
            e.printStackTrace();  
        }  
        *//** 请求失败处理 *//*  
        if(null==result){  
            return "对不起，你说的话真是太高深了……";  
        }  
          
        try {  
            JSONObject json = new JSONObject(result);  
            //以code=100000为例，参考图灵机器人api文档  
            if(100000==json.getInt("code")){  
                result = json.getString("text");  
            }  
        } catch (JSONException e) {  
            // TODO Auto-generated catch block  
            e.printStackTrace();  
        } */ 
        String result = "你好！测试成功了！······";
        return result;  
    }  

}

原文地址：http://down.chinaz.com/try/201408/2492_2.htm