初识Java微信公众号开发

微信开发，需要两个前提:

1.把本地映射到外网

2.一个公共号

1.用ngrok把本地地址映射到外网

先编写接入接口

工具类

package com.imooc.util;

import java.io.UnsupportedEncodingException;
import java.security.MessageDigest;
import java.security.NoSuchAlgorithmException;
import java.util.Arrays;

public class CheckUtil {
	private static final String token ="immoc";
	public static boolean checkSignature(String signature,String timestamp,String nonce) throws NoSuchAlgorithmException{
		String[] arr = new String[]{token,timestamp,nonce};
		
		//加密/校验流程如下：
		//1. 将token、timestamp、nonce三个参数进行字典序排序
		Arrays.sort(arr);
		//2. 将三个参数字符串拼接成一个字符串进行sha1加密
		StringBuffer sb = new StringBuffer();
		for(int i=0;i>> 4 & 0xf];
	            buf[k++] = hexDigits[byte0 & 0xf];
	        }
	        return new String(buf);
	    } catch (NoSuchAlgorithmException e) {
	        e.printStackTrace();
	    } catch (UnsupportedEncodingException e) {
	        e.printStackTrace();
	    }
	    return str;
	}
	
	
}

Servlet类

package com.imooc.servlet;

import java.io.IOException;
import java.io.PrintWriter;
import java.security.NoSuchAlgorithmException;
import java.util.Date;
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.imooc.po.TextMessage;
import com.imooc.util.CheckUtil;
import com.imooc.util.MessageUtil;

/**
 * Servlet implementation class WeixinServlet
 */
public class WeixinServlet extends HttpServlet {
	private static final long serialVersionUID = 1L;

    /**
     * Default constructor. 
     */
    public WeixinServlet() {
        // TODO Auto-generated constructor stub
    }

	/**
	 * 
		参数	描述
		signature	微信加密签名，signature结合了开发者填写的token参数和请求中的timestamp参数、nonce参数。
		timestamp	时间戳
		nonce	随机数
		echostr	随机字符串
	 * @see HttpServlet#doGet(HttpServletRequest request, HttpServletResponse response)
	 */
	protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
		String signature = request.getParameter("signature");
		String timestamp = request.getParameter("timestamp");
		String nonce = request.getParameter("nonce");
		String echostr = request.getParameter("echostr");
		
		PrintWriter out = response.getWriter();
		try {
			if(CheckUtil.checkSignature(signature, timestamp, nonce)){
				out.write(echostr);
			}
		} catch (NoSuchAlgorithmException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		}
	}
}

访问地址是

http://localhost:8080/weixin/WeixinServlet

用ngrok映射命令是.先跳转到ngrok目录下面，敲击名利：

ngrok http 8080

现在就可以在外网用

http://9a62752d.ngrok.io/weixin/WeixinServlet

访问写的方法

2.一个公共号

   因为公共号需要自己的微信号绑定身份证，银行卡。个人只能申请“订阅号”。“企业号”，“服务号”不是个人开的。而且发微信的数量还有限制。

   所以我找了个微信测试号

  

   测试账号申请地址

  http://mp.weixin.qq.com/debug/cgi-bin/sandboxinfo?action=showinfo&t=sandbox/index

配置 相应的url，和token

  

填写了后发现验证成功，

下面继续写可以正确接收，发送消息

先看开发文档，用最简单的text类型

还是刚才那个servlet，只不过现在是post方法

package com.imooc.util;

import java.io.IOException;
import java.io.InputStream;
import java.util.Date;
import java.util.HashMap;
import java.util.List;
import java.util.Map;

import javax.servlet.http.HttpServletRequest;

import org.dom4j.Document;
import org.dom4j.DocumentException;
import org.dom4j.Element;
import org.dom4j.io.SAXReader;

import com.imooc.po.TextMessage;
import com.thoughtworks.xstream.XStream;

public class MessageUtil {
	public static final String MESSAGE_TYPE_TEXT="text";
	/**
	 * xml改成map
	 * @param request
	 * @return
	 * @throws IOException
	 * @throws DocumentException
	 */
	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 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.setContent(content);
		text.setFromUserName(toUserName);
		text.setToUserName(fromUserName);
		text.setCreateTime(new Date().getTime());
		text.setMsgType(MessageUtil.MESSAGE_TYPE_TEXT);
		return MessageUtil.textMessageToXml(text);
	}
	/**
	 * 天气查询
	 * @return String
	 */
	public static String weatherMenu(){
		StringBuffer sb=new StringBuffer();
		sb.append("天气预报查询正在开发中……");
		return sb.toString();
	}
}

package com.imooc.servlet;

import java.io.IOException;
import java.io.PrintWriter;
import java.security.NoSuchAlgorithmException;
import java.util.Date;
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.imooc.po.TextMessage;
import com.imooc.util.CheckUtil;
import com.imooc.util.MessageUtil;

/**
 * Servlet implementation class WeixinServlet
 */
public class WeixinServlet extends HttpServlet {
	private static final long serialVersionUID = 1L;

    /**
     * Default constructor. 
     */
    public WeixinServlet() {
        // TODO Auto-generated constructor stub
    }

	/**
	 * 
		参数	描述
		signature	微信加密签名，signature结合了开发者填写的token参数和请求中的timestamp参数、nonce参数。
		timestamp	时间戳
		nonce	随机数
		echostr	随机字符串
	 * @see HttpServlet#doGet(HttpServletRequest request, HttpServletResponse response)
	 */
	protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
		String signature = request.getParameter("signature");
		String timestamp = request.getParameter("timestamp");
		String nonce = request.getParameter("nonce");
		String echostr = request.getParameter("echostr");
		
		PrintWriter out = response.getWriter();
		try {
			if(CheckUtil.checkSignature(signature, timestamp, nonce)){
				out.write(echostr);
			}
		} catch (NoSuchAlgorithmException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		}
	}

	/**
	 * 文本消息接收响应
	 	ToUserName	开发者微信号
		FromUserName	发送方帐号（一个OpenID）
		CreateTime	消息创建时间 （整型）
		MsgType	text
		Content	文本消息内容
		MsgId	消息id，64位整型
	 * @see HttpServlet#doPost(HttpServletRequest request, HttpServletResponse response)
	 */
	protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
		response.setCharacterEncoding("UTF-8");
		request.setCharacterEncoding("UTF-8");
		PrintWriter out = response.getWriter();
		try {
			Map requestMap = MessageUtil.xmlToMap(request);
			// 发送方帐号（open_id）
			String fromUserName = requestMap.get("FromUserName");
			// 公众帐号
			String toUserName = requestMap.get("ToUserName");
			// 消息类型
			String MsgType = requestMap.get("MsgType");
			// 消息内容
			String content = requestMap.get("Content");
			String message = null;
			if("text".equals(MsgType)){
				/*TextMessage text = new TextMessage();
				text.setFromUserName(fromUserName);
				text.setToUserName(toUserName);
				text.setMsgType("text");
				text.setCreateTime(new Date().getTime());
				text.setContent("您发送的信息是:"+content);
				
				message = MessageUtil.textMessageToXml(text);*/
				message = MessageUtil.initText(toUserName, fromUserName,
						MessageUtil.weatherMenu());
			}
			System.out.println(message);
			out.print(message);
		} catch (DocumentException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		}finally{
			out.close();
		}
		
	}

}

发送了消息后