Analyze the second step of java WeChat development API to obtain and reply to messages

This article mainly analyzes java WeChat developmentAPIThe second step is to obtain and reply to messages. Interested friends can refer to

How to obtain and reply to WeChat development API News, I will introduce it to you below

1. Description
* This example is based on the WeChat development document:http://mp.weixin.qq.com/wiki /home/index.htmlLatest version (4/3/2016 5:34:36 PM) for development demonstration.
* Editing platform: myeclipse10.7+win32+jdk1.7+tomcat7.0
* Server: Alibaba Cloud windows server 2008 64bits
* Platform requirements: servletUse annotation method, Platform requirements: j2ee6.0+, jdk6.0+, tomcat7.0+
* The demonstration focuses more on API analysis.
* To facilitate test description, each test case is independent and does not depend on other methods. Don't think much about packaging.
* The demonstration should be carried out in accordance with the API requirements as much as possible. The purpose is to understand how to use the document and achieve the effect of drawing inferences from one example.
* Knowledge requirements: a solid java foundation, understanding of http network communication knowledge, sufficient understanding of javaweb, jsonanalysis
* At the end of each article, the source code of this part of the demonstration will be given. After analyzing the API, all demonstration source codes will be provided in the form of source code packages.
* Current time: 4/3/2016 5:32:57 PM, subject to this time.

2. Original document - Message Management (Abstract)
•Document address: http://mp.weixin.qq .com/wiki/17/f298879f8fb29ab98b2f2971d42552fd.html

•Message management
◦Receive message-Receive normal message
◦Receive message-Receive event Push
◦Send message-Passive reply message
◦Send message-Encryption and decryption during passive reply
◦Send message-Customer service message
◦Send message-Group interface
◦Send message-template Message interface
◦Send message-template message operation specification
◦Get public account automatic reply configuration

3. Document understanding
•Receive Message
◦The document explains this: When an ordinary WeChat user sends a message to a public account, the WeChat server will POST the XML data packet of the message to the URL filled in by the developer.
◦Understanding: The WeChat server returns the message sent by the user to req in the form of Post stream. When we want to get the message sent by the user, we can get it through req.getInputStream(). Of course, we can perform necessary parsing based on the xml format of the message returned in the document.
◦
Implementation:

/*
 * 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);
} 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");

•Send a message
◦The document explains this: When a user sends a message to an official account (or a certain When events triggered by some specific user operations are pushed), a POST request will be generated. Developers can return a specific XML structure in the response package (Get) to respond to the message (reply text is now supported) , pictures, graphics, text, voice, video, music). Strictly speaking, sending a passive response message is not actually an interface, but a reply to a message sent by the WeChat server.
◦Understanding: When a user sends a request, a POST request will be generated, and we can reply to the message through Respone. However, the reply content has strict format requirements. Only if the format requirements are met, the WeChat server will process it and return it to the user. By looking at the "Message Management" module of the document, we can see that there are various messages in WeChat. Each type of message has its own specific format requirements. We must follow the requirements to return specific information to the user normally. We try to reply text messages and graphic messages to users according to the required format of the document. Key point: Construct the required parameters according to the document requirements. Special note: parameters are case-sensitive.
◦Implementation 1-Reply to ordinary text messages:

//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);

◦Implementation 2-Reply to graphic messages:

//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("我是图片标题");
a.setUrl("www.baidu.com");// 该地址是点击图片跳转后
a.setPicUrl("http://b.hiphotos.baidu.com/image/pic/item/08f790529822720ea5d058ba7ccb0a46f21fab50.jpg");// 该地址是一个有效的图片地址
a.setDescription("我是图片的描述");
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);

All operation source codes in this part can be used directly
•CoreServlet.java (including server access, receiving messages sent by users, replying to ordinary text messages, and replying to graphic messages. Requires third-party jars: dom4j, xstream)

package com.gist.servlet;

import java.io.IOException;
import java.io.InputStream;
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.annotation.WebServlet;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

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

import com.gist.bean.Article;
import com.gist.bean.PicAndTextMsg;
import com.thoughtworks.xstream.XStream;

/**
 * @author 高远</n> 邮箱：wgyscsf@163.com</n> 博客 http://www.php.cn/;/n>
 *  编写时期 2016-4-3 下午4:34:05
 */
@WebServlet("/CoreServlet")
public class CoreServlet extends HttpServlet {
 private static final long serialVersionUID = 1L;
 String TAG = "CoreServlet";

 /*
 * 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。
 */
 @Override
 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 = "wgyscsf";
 // 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");
 // // 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");
 }
 }

 /*
 * 查看api文档关于收发消息推送的消息格式基本一致。 如以下格式： <xml>
 * <ToUserName><![CDATA[toUser]]></ToUserName>
 * <FromUserName><![CDATA[fromUser]]></FromUserName>
 * <CreateTime>1348831860</CreateTime> <MsgType><![CDATA[text]]></MsgType>
 * <Content><![CDATA[this is a test]]></Content>
 * <MsgId>1234567890123456</MsgId> </xml> 那么，我们就可以进行统一处理。
 */
 /*
 * 我们先获取输入流，看输入流里面的信息。通过测试打印输出流，我们可以看到每次用户请求，都会收到req请求，请求格式是xml格式，该信息在文档中有说明。
 */
 /*
 * 特别注意，req.getInputStream()只能获取一次，并且只能读取一次。如果想要多次读取，需要另外想办法。为了简单起见，
 * 我们只获取一次req.getInputStream()，不再打印输出流信息。直接打印解析后的信息。
 */
 @Override
 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);
 } 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("我是图片标题");
 a.setUrl("www.baidu.com");// 该地址是点击图片跳转后
 a.setPicUrl("http://b.hiphotos.baidu.com/image/pic/item/08f790529822720ea5d058ba7ccb0a46f21fab50.jpg");// 该地址是一个有效的图片地址
 a.setDescription("我是图片的描述");
 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);
 }
}

•TestMsg.java (ordinary Text message bean)

package com.gist.bean;

/**
 * @author 高远</n> 邮箱：wgyscsf@163.com</n> 博客 http://www.php.cn/;/n>
 *  编写时期 2016-4-4 下午2:09:27
 */
public class TextMsg {
 private String ToUserName;
 private String FromUserName;
 private long CreateTime;
 private String MsgType;

 @Override
 public String toString() {
 return "TextMsg [ToUserName=" + ToUserName + ", FromUserName="
  + FromUserName + ", CreateTime=" + CreateTime + ", MsgType="
  + MsgType + ", Content=" + Content + "]";
 }

 private String Content;

 public TextMsg(String toUserName, String fromUserName, long createTime,
  String msgType, String content) {
 super();
 ToUserName = toUserName;
 FromUserName = fromUserName;
 CreateTime = createTime;
 MsgType = msgType;
 Content = content;
 }

 public TextMsg() {
 super();
 }

 public String getToUserName() {
 return ToUserName;
 }

 public void setToUserName(String toUserName) {
 ToUserName = toUserName;
 }

 public String getFromUserName() {
 return FromUserName;
 }

 public void setFromUserName(String fromUserName) {
 FromUserName = fromUserName;
 }

 public long getCreateTime() {
 return CreateTime;
 }

 public void setCreateTime(long createTime) {
 CreateTime = createTime;
 }

 public String getMsgType() {
 return MsgType;
 }

 public void setMsgType(String msgType) {
 MsgType = msgType;
 }

 public String getContent() {
 return Content;
 }

 public void setContent(String content) {
 Content = content;
 }
}

•Article.java(Picture and text message internal Article bean)

##

package com.gist.bean;

/**
 * @author 高远</n> 邮箱：wgyscsf@163.com</n> 博客 http://www.php.cn/;/n>
 *  编写时期 2016-4-4 下午2:47:08
 */
public class Article {
 private String Title;

 @Override
 public String toString() {
 return "item [Title=" + Title + ", Description=" + Description
  + ", PicUrl=" + PicUrl + ", Url=" + Url + "]";
 }

 public String getTitle() {
 return Title;
 }

 public void setTitle(String title) {
 Title = title;
 }

 public String getDescription() {
 return Description;
 }

 public void setDescription(String description) {
 Description = description;
 }

 public String getPicUrl() {
 return PicUrl;
 }

 public void setPicUrl(String picUrl) {
 PicUrl = picUrl;
 }

 public String getUrl() {
 return Url;
 }

 public void setUrl(String url) {
 Url = url;
 }

 private String Description;
 private String PicUrl;
 private String Url;

}

•PicAndTextMsg.java(Picture and text message bean)

package com.gist.bean;

import java.util.List;

/**
 * @author 高远</n> 邮箱：wgyscsf@163.com</n> 博客 http://www.php.cn/;/n>
 *  编写时期 2016-4-4 下午2:47:08
 */
public class PicAndTextMsg {
 private String ToUserName;
 private String FromUserName;
 private long CreateTime;
 private String MsgType;
 private int ArticleCount;
 private List<Article> Articles;

 @Override
 public String toString() {
 return "PicAndTextMsg [ToUserName=" + ToUserName + ", FromUserName="
  + FromUserName + ", CreateTime=" + CreateTime + ", MsgType="
  + MsgType + ", ArticleCount=" + ArticleCount + ", Articles="
  + Articles + "]";
 }

 public String getToUserName() {
 return ToUserName;
 }

 public void setToUserName(String toUserName) {
 ToUserName = toUserName;
 }

 public String getFromUserName() {
 return FromUserName;
 }

 public void setFromUserName(String fromUserName) {
 FromUserName = fromUserName;
 }

 public long getCreateTime() {
 return CreateTime;
 }

 public void setCreateTime(long createTime) {
 CreateTime = createTime;
 }

 public String getMsgType() {
 return MsgType;
 }

 public void setMsgType(String msgType) {
 MsgType = msgType;
 }

 public int getArticleCount() {
 return ArticleCount;
 }

 public void setArticleCount(int articleCount) {
 ArticleCount = articleCount;
 }

 public List<Article> getArticles() {
 return Articles;
 }

 public void setArticles(List<Article> articles) {
 Articles = articles;
 }

}

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