Java:实现微信公众平台

1.  Easyui学习班.jpg    

2. [文件] web.xml ~ 755B

<?xml version="1.0" encoding="UTF-8"?> 
<web-app xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" 
    xmlns="http://java.sun.com/xml/ns/javaee" xmlns:web="http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd" 
    xsi:schemaLocation="http://java.sun.com/xml/ns/javaee http://java.sun.com/xml/ns/javaee/web-app_3_0.xsd" 
    id="WebApp_ID" version="3.0"> 
    <display-name>微信公共平台开发者接口</display-name> 
    <filter> 
        <filter-name>WeChatFilter</filter-name> 
        <filter-class>com.gson.WeChatFilter</filter-class> 
    </filter> 
    <filter-mapping> 
        <filter-name>WeChatFilter</filter-name> 
        <url-pattern>/wechat/*</url-pattern> 
    </filter-mapping> 
 
    <welcome-file-list> 
        <welcome-file>index.jsp</welcome-file> 
    </welcome-file-list> 
</web-app> 

#p#

3. [文件] WeChatFilter.java

package com.gson; 
 
import java.io.File; 
import java.io.FileInputStream; 
import java.io.FileNotFoundException; 
import java.io.IOException; 
import java.util.Date; 
import java.util.Properties; 
 
import javax.servlet.Filter; 
import javax.servlet.FilterChain; 
import javax.servlet.FilterConfig; 
import javax.servlet.ServletException; 
import javax.servlet.ServletInputStream; 
import javax.servlet.ServletRequest; 
import javax.servlet.ServletResponse; 
import javax.servlet.http.HttpServletRequest; 
import javax.servlet.http.HttpServletResponse; 
 
import org.apache.log4j.Logger; 
 
import com.gson.bean.Articles; 
import com.gson.bean.InMessage; 
import com.gson.bean.OutMessage; 
import com.gson.inf.MessageProcessingHandler; 
import com.gson.util.Tools; 
import com.gson.util.XStreamFactory; 
import com.thoughtworks.xstream.XStream; 
 
/** 
 * 请求拦截 
 * @author GodSon 
 * 
 */ 
public class WeChatFilter implements Filter { 
     
    private final Logger logger = Logger.getLogger(WeChatFilter.class); 
    private String _token; 
    private String conf = "classPath:wechat.properties"; 
    private String defaultHandler = "com.gson.inf.DefaultMessageProcessingHandlerImpl"; 
    private Properties p; 
 
    @Override 
    public void destroy() { 
        logger.info("WeChatFilter已经销毁"); 
    } 
 
    @Override 
    public void doFilter(ServletRequest req, ServletResponse res, FilterChain chain) throws IOException, ServletException { 
        HttpServletRequest request = (HttpServletRequest) req; 
        HttpServletResponse response = (HttpServletResponse) res; 
        Boolean isGet = request.getMethod().equals("GET"); 
         
        String path = request.getServletPath(); 
        String pathInfo = path.substring(path.lastIndexOf("/")); 
         
        if (pathInfo == null) { 
            response.getWriter().write("error"); 
        } else { 
            _token = pathInfo.substring(1); 
            if (isGet) { 
                doGet(request, response); 
            } else { 
                doPost(request, response); 
            } 
        } 
    } 
 
    private void doPost(HttpServletRequest request, HttpServletResponse response) throws IOException { 
        response.setCharacterEncoding("UTF-8"); 
        response.setContentType("text/xml"); 
         
        OutMessage oms = new OutMessage(); 
        ServletInputStream in = request.getInputStream(); 
        //转换微信post过来的xml内容 
        XStream xs = XStreamFactory.init(false); 
        xs.alias("xml", InMessage.class); 
        String xmlMsg = Tools.inputStream2String(in); 
        InMessage msg = (InMessage) xs.fromXML(xmlMsg); 
        //获取自定消息处理器，如果自定义处理器则使用默认处理器。 
        String handler = p.getProperty("MessageProcessingHandlerImpl"); 
        if(handler== null) 
            handler = defaultHandler; 
         
        try { 
            //加载处理器 
            Class<?> clazz = Class.forName(handler); 
            MessageProcessingHandler processingHandler = (MessageProcessingHandler) clazz.newInstance(); 
            //取得消息类型 
            String type = msg.getMsgType(); 
            //针对不同类型消息进行处理 
            if (type.equals(MessageProcessingHandler.MSG_TYPE_TEXT)) { 
                oms = processingHandler.textTypeMsg(msg); 
            } else if (type.equals(MessageProcessingHandler.MSG_TYPE_LOCATION)) { 
                oms = processingHandler.locationTypeMsg(msg); 
            } else if (type.equals(MessageProcessingHandler.MSG_TYPE_LINK)) { 
                oms = processingHandler.linkTypeMsg(msg); 
            } else if (type.equals(MessageProcessingHandler.MSG_TYPE_IMAGE)) { 
                oms = processingHandler.imageTypeMsg(msg); 
            } else if (type.equals(MessageProcessingHandler.MSG_TYPE_EVENT)) { 
                oms = processingHandler.eventTypeMsg(msg); 
            } 
            if(oms == null){ 
                oms = new OutMessage(); 
                oms.setContent("系统错误!"); 
            } 
            //设置发送信息 
            oms.setCreateTime(new Date().getTime()); 
            oms.setToUserName(msg.getFromUserName()); 
            oms.setFromUserName(msg.getToUserName()); 
        } catch (ClassNotFoundException e) { 
            logger.error("没有找到" + handler + "类", e); 
            oms.setContent("系统错误！"); 
        } catch (InstantiationException e) { 
            logger.error(e); 
            oms.setContent("系统错误！"); 
        } catch (IllegalAccessException e) { 
            logger.error(e); 
            oms.setContent("系统错误！"); 
        } 
         
        //把发送发送对象转换为xml输出 
        xs = XStreamFactory.init(false); 
        xs.alias("xml", OutMessage.class); 
        xs.alias("item", Articles.class); 
        xs.toXML(oms, response.getWriter()); 
    } 
 
    private void doGet(HttpServletRequest request, HttpServletResponse response) throws IOException { 
        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");// 
        //验证 
        if (Tools.checkSignature(_token, signature, timestamp, nonce)) { 
            response.getWriter().write(echostr); 
        } 
    } 
 
    /** 
     * 启动的时候加载wechat.properties配置 
     * 可以在过滤器配置wechat.properties路径 
     */ 
    @Override 
    public void init(FilterConfig config) throws ServletException { 
        String cf = config.getInitParameter("conf"); 
        if (cf != null) { 
            conf = cf; 
        } 
        String classPath = this.getClass().getResource("/").getPath().replaceAll("%20", " "); 
        conf = conf.replace("classPath:", classPath); 
        p = new Properties(); 
        File pfile = new File(conf); 
        if (pfile.exists()) { 
            try { 
                p.load(new FileInputStream(pfile)); 
            } catch (FileNotFoundException e) { 
                logger.error("未找到wechat.properties", e); 
            } catch (IOException e) { 
                logger.error("wechat.properties读取异常", e); 
            } 
        } 
        logger.info("WeChatFilter已经启动！"); 
    } 
 
} 

原文链接：http://www.oschina.net/code/snippet_98719_21419