如何用java开发微信
说明：
本次的教程主要是对微信公众平台开发者模式的讲解，网络上很多类似文章，但很多都让初学微信开发的人一头雾水，所以总结自己的微信开发经验，将微信开发的整个过程系统的列出，并对主要代码进行讲解分析，让初学者尽快上手。
在阅读本文之前，应对微信公众平台的官方开发文档有所了解，知道接收和发送的都是xml格式的数据。另外，册渗在做内容回复时用到了图灵机器人的api接口，这是一个自然语言解析的开放平台，可以帮我们解决整个微信开发过程中最困难的问题，此处不多讲，下面会有其详细的调用方式。
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，代码如下：
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package demo.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;
import demo.process.WechatProcess;
/**
* 微信服务端收发消息接口
*
* @author pamchen-1
*
*/
public class WechatServlet 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
* 察数@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 败姿首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 WechatProcess().processWechatMag(xml);
}
try {
OutputStream os = response.getOutputStream();
os.write(result.getBytes("UTF-8"));
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);
}
}
<?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">
<servlet>
<description>This is the description of my J2EE component</description>
<display-name>This is the display name of my J2EE component</display-name>
<servlet-name>WechatServlet</servlet-name>
<servlet-class>demo.servlet.WechatServlet</servlet-class>
</servlet>
<servlet-mapping>
<servlet-name>WechatServlet</servlet-name>
<url-pattern>/wechat.do</url-pattern>
</servlet-mapping>
<welcome-file-list>
<welcome-file>index.jsp</welcome-file>
</welcome-file-list>
</web-app>
package demo.process;
import java.util.Date;
import demo.entity.ReceiveXmlEntity;
/**
* 微信xml消息处理流程逻辑类
* @author pamchen-1
*
*/
public class WechatProcess {
/**
* 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 processWechatMag(String xml){
/** 解析xml数据 */
ReceiveXmlEntity xmlEntity = new ReceiveXmlProcess().getMsgEntity(xml);
/** 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())){
result = new TulingApiProcess().getTulingResult(xmlEntity.getContent());
}
/** 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
* */
result = new FormatXmlProcess().formatXmlAnswer(xmlEntity.getFromUserName(), xmlEntity.getToUserName(), result);
return result;
}
}
package demo.entity;
/**
* 接收到的微信xml实体类
* @author pamchen-1
*
*/
public class ReceiveXmlEntity {
private String ToUserName="";
private String FromUserName="";
private String CreateTime="";
private String MsgType="";
private String MsgId="";
private String Event="";
private String EventKey="";
private String Ticket="";
private String Latitude="";
private String Longitude="";
private String Precision="";
private String PicUrl="";
private String MediaId="";
private String Title="";
private String Description="";
private String Url="";
private String Location_X="";
private String Location_Y="";
private String Scale="";
private String Label="";
private String Content="";
private String Format="";
private String Recognition="";
public String getRecognition() {
return Recognition;
}
public void setRecognition(String recognition) {
Recognition = recognition;
}
public String getFormat() {
return Format;
}
public void setFormat(String format) {
Format = format;
}
public String getContent() {
return Content;
}
public void setContent(String content) {
Content = content;
}
public String getLocation_X() {
return Location_X;
}
public void setLocation_X(String locationX) {
Location_X = locationX;
}
public String getLocation_Y() {
return Location_Y;
}
public void setLocation_Y(String locationY) {
Location_Y = locationY;
}
public String getScale() {
return Scale;
}
public void setScale(String scale) {
Scale = scale;
}
public String getLabel() {
return Label;
}
public void setLabel(String label) {
Label = label;
}
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 getUrl() {
return Url;
}
public void setUrl(String url) {
Url = url;
}
public String getPicUrl() {
return PicUrl;
}
public void setPicUrl(String picUrl) {
PicUrl = picUrl;
}
public String getMediaId() {
return MediaId;
}
public void setMediaId(String mediaId) {
MediaId = mediaId;
}
public String getEventKey() {
return EventKey;
}
public void setEventKey(String eventKey) {
EventKey = eventKey;
}
public String getTicket() {
return Ticket;
}
public void setTicket(String ticket) {
Ticket = ticket;
}
public String getLatitude() {
return Latitude;
}
public void setLatitude(String latitude) {
Latitude = latitude;
}
public String getLongitude() {
return Longitude;
}
public void setLongitude(String longitude) {
Longitude = longitude;
}
public String getPrecision() {
return Precision;
}
public void setPrecision(String precision) {
Precision = precision;
}
public String getEvent() {
return Event;
}
public void setEvent(String event) {
Event = event;
}
public String getMsgId() {
return MsgId;
}
public void setMsgId(String msgId) {
MsgId = msgId;
}
public String getToUserName() {
return ToUserName;
}
public void setToUserName(String toUserName) {
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
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1.3 通过以上代码，我们已经实现了微信公众平台开发的框架，即开通开发者模式并成功接入、接收消息和发送消息这三个步骤。
下面就讲解其核心部分——解析接收到的xml数据，并以文本类消息为例，通过图灵机器人api接口实现智能回复。
2.1 首先看一下整体流程处理代码，包括：xml数据处理、调用图灵api、封装返回的xml数据。
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2.2 解析接收到的xml数据，此处有两个类，ReceiveXmlEntity.java和ReceiveXmlProcess.java，通过反射的机制动态调用实体类中的set方法，可以避免很多重复的判断，提高代码效率，代码如下：
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