微信公众号开发--关注后自动回复（Java记录篇）

转载自 http://blog.csdn.net/lyq8479/article/details/8944988文中所用到的jar dom4j XStream的jar包扫描下方二维码可关注你我杂志刊关注或者微信搜索公众号你我杂志刊开发者通过signature对请求进行校验，若确认此次校验来自微信服务器，请原样返回echostr参数内容，则接入成功，否则接入失败！打开IDE

甄齐才

34195人浏览 · 2017-09-20 21:07:37

甄齐才 · 2017-09-20 21:07:37 发布

转载自 http://blog.csdn.net/lyq8479/article/details/8944988
访问我的个人博客秋码个人博客
文中所用到的jar dom4j XStream的jar包
扫描下方二维码可关注你我杂志刊关注或者微信搜索公众号你我杂志刊
这里写图片描述
开发者通过signature对请求进行校验，若确认此次校验来自微信服务器，请原样返回echostr参数内容，则接入成功，否则接入失败！
打开IDE,创建一个Java Web工程，并新建一个能够处理请求的Servlet，命名任意。

package com.zhenqi.servlet;

import com.zhenqi.util.CheckUtil;
import com.zhenqi.util.MessageUtil;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.IOException;
import java.io.PrintWriter;
import java.util.ArrayList;
import java.util.Date;
import java.util.List;
import java.util.Map;

/**
 * Created by wuming on 2017/9/15.
 */
public class HandleWeiXinMessageServlet extends HttpServlet {

    public static final Logger logger = LoggerFactory.getLogger(HandleWeiXinMessageServlet.class);
    /**
     * VersionUID
     */
    private static final long serialVersionUID = 1L;
   

    /*
     * URL验证
     * (non-Javadoc)
     * @see javax.servlet.http.HttpServlet#doGet(javax.servlet.http.HttpServletRequest, javax.servlet.http.HttpServletResponse)
     */
    @Override
    protected void doGet(HttpServletRequest req, HttpServletResponse resp)
            throws ServletException, IOException {

        String signature = req.getParameter("signature");
        String timestamp = req.getParameter("timestamp");
        String nonce = req.getParameter("nonce");
        String echostr = req.getParameter("echostr");
        logger.info("echostr" + echostr);
        PrintWriter out = resp.getWriter();
        if(CheckUtil.checkSignature(signature, timestamp, nonce)){
        	out.write(echostr);
        } 
    }

以上servlet doGet方法请求用到了校验signature的方法，以下是CheckUtil.java完整代码。
其中要注意Token要与微信相对应。
这里写图片描述

package com.zhenqi.util;

import java.security.MessageDigest;
import java.util.Arrays;

public class CheckUtil {
	//与接口配置信息中的Token要一致 
	private static final String token="weixinStudy";
	
	public static boolean checkSignature(String signature,String timestrap,
			String nonce){
		
		String[] arr=new String[]{token,timestrap,nonce};
		// 将token、timestamp、nonce三个参数进行字典序排序 
		Arrays.sort(arr);
		
		StringBuffer buf=new StringBuffer();
		for(int i=0;i<arr.length;i++){
			buf.append(arr[i]);
		}
		
		String temp=getSha1(buf.toString());
		return temp.equals(signature);
	}
	
	public static String getSha1(String str){
		if(null==str || str.length()==0){
			return null;
		}
		char hexDigits[]={'0','1','2','3','4','5','6','7','8','9',
				'a','b','c','d','e','f'};
		try{
			MessageDigest mdTemp=MessageDigest.getInstance("SHA1");
			mdTemp.update(str.getBytes("UTF-8"));
			
			byte[] md=mdTemp.digest();
			int j=md.length;
			char[] buf=new char[j*2];
			int k=0;
			for(int i=0;i<j;i++){
				byte byTemp=md[i];
				buf[k++]=hexDigits[byTemp >>> 4 & 0xf];
				buf[k++]=hexDigits[byTemp & 0xf];
			}
			return new String(buf);
		}catch(Exception e){
			return null;
		}
	}

}

而后再回到servlet请求类里，编写doPost方法。用户关注就是触发一个事件。

protected void doPost(HttpServletRequest req, HttpServletResponse resp)
            throws ServletException, IOException {

    	req.setCharacterEncoding("UTF-8");
        resp.setCharacterEncoding("UTF-8");
        PrintWriter out = resp.getWriter();
        try {
            Map<String,String> map = MessageUtil.xmlToMap(req);
            String toUserName = map.get("ToUserName");
            String fromUserName = map.get("FromUserName");
            String msgType = map.get("MsgType");
            String content = map.get("Content");    
            //判断请求是否事件类型 event
           if(MessageUtil.MESSAGE_EVENT.equals(msgType)){
                String eventType = map.get("Event");
                //若是关注事件  subscribe
                if(MessageUtil.EVENT_SUB.equals(eventType)){
                    String mycontent = MessageUtil.menuText();
                    message = MessageUtil.initText(toUserName, fromUserName, mycontent);

                }
            } 
            out.print(message);
        } catch (Exception e) {
        	e.printStackTrace();
            out.close();
        }   
       
    }

MessageUtl.java类如下：

public class MessageUtil {
	public static final String MESSAGE_TEXT = "text";
    public static final String MESSAGE_IMAGE = "image";
    public static final String MESSAGE_VOICE = "voice";
    public static final String MESSAGE_VIDEO = "video";
    public static final String MESSAGE_LINK = "link";
    public static final String MESSAGE_LOCATION = "location";
    public static final String MESSAGE_EVENT = "event";

    public static final String EVENT_SUB = "subscribe";
    public static final String EVENT_UNSUB = "unsubscribe";
    public static final String EVENT_CLICK = "CLICK";
    public static final String EVENT_VIEW = "VIEW";

    /**
     * xml转为map
     * @param request
     * @return
     * @throws DocumentException
     * @throws IOException
     */
    public static Map<String, String> xmlToMap(HttpServletRequest request ) throws DocumentException, IOException
    {
        Map<String,String> map = new HashMap<String, String>();

        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;
    }

    public static String textMessageToXml(TextMessage textMessage){
        XStream xstream = new XStream();
        xstream.alias("xml", textMessage.getClass());
        return xstream.toXML(textMessage);

    }
    public static String initText(String toUserName, String fromUserName, String content){
        TextMessage text = new TextMessage();
        text.setFromUserName(toUserName);
        text.setToUserName(fromUserName);
        text.setMsgType(MESSAGE_TEXT);
        text.setCreateTime(new Date().getTime());
        text.setContent(content);
        return textMessageToXml(text);
    }

    public static String menuText(){
        StringBuffer sb = new StringBuffer();
        sb.append("      你关注，\n");
        sb.append("     或者不关注，\n");
        sb.append("      【你我杂志刊】都在这里!\n");
        sb.append("     不离，\n");
        sb.append("      不弃！\n\n");
        sb.append("该公众号已实现以下功能：\n");
        sb.append("回复“天气”、“翻译” 将有该功能的介绍与使用，\n");
        sb.append("如您在使用该公众有任何宝贵意见，欢迎反馈！\n\n");
        sb.append("反馈邮箱：zhenqicai@sohu.com");
        return sb.toString();       
    }
}

最终效果如下图
这里写图片描述
扫描下方二维码可关注你我杂志刊关注或者微信搜索公众号你我杂志刊