java微信公众号开发案例

微信公众号开发一般是针对企业和组织的，个人一般只能申请订阅号，并且调用的接口有限，下面我们就来简单的描述下接入公众号的步骤：

1、首先你需要一个邮箱在微信公众号平台进行注册；
     注册的方式有订阅号、公众号、小程序和企业号，个人我们这里只能选择订阅号

2、注册完后，我们登录到公众号平台--->开发--->基本配置,这里需要填写URL和token，URL就是我们使用服务器的接口；

3、Java Web服务器程序编译好且在服务器上部署可以运行的话，可在微信公众号进行在线接口调试：

    1）、选择合适的接口
    2）、系统会生成该接口的参数表，您可以直接在文本框内填入对应的参数值（红色星号表示该字段必填）
    3）、点击检查问题按钮，即可得到相应的调试信息

   eg:获取access_token的步骤：

   1）、接口类型：基础支持
   2）、接口列表：获取access_token接口/token
   3）、填写相应的参数：grant_type、appid、secret
   4）、点击检查问题
   5）、验证成功会返回结果和提示，结果为：200 ok,提示：Request successful即表示验证成功

   我们这里验证比较多的是消息接口调试：文本消息、图片消息、语音消息、视频消息、etc

4、接口有不理解的地方，可进入开发-->开发者工具-->开发者文档进行查询

5、接口权限：订阅号主要有基础支持、接收消息及网页服务里面的一些接口

下面我们主要讲订阅号怎么样接收消息的案例：

1、需要申请一个个人微信订阅号
2、url服务器和服务器端代码部署（可以用腾讯云or阿里云服务器）

1）、AccountsServlet.java类，验证来自微信服务器和微信服务器的消息处理

package cn.jon.wechat.servlet;

import java.io.IOException;
import java.io.PrintWriter;

import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

import cn.jon.wechat.service.AccountsService;
import cn.jon.wechat.utils.SignUtil;

public class AccountsServlet extends HttpServlet {

public AccountsServlet() {
super();
}

public void destroy() {
super.destroy();
// Put your code here
}
/**
* 确认请求来自于微信服务器
*/

public void doGet(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
System.out.println("接口测试开始！！！");
//微信加密签名
String signature = request.getParameter("signature");
//时间戳
String timestamp = request.getParameter("timestamp");
//随机数
String nonce = request.getParameter("nonce");
//随机字符串
String echostr = request.getParameter("echostr");

PrintWriter out = response.getWriter();
//通过校验signature对请求进行校验，若校验成功则原样返回echostr，表示接入成功，否则接入失败
if(SignUtil.checkSignature(signature,timestamp,nonce)){
out.print(echostr);
}
out.close();
out = null;
// response.encodeRedirectURL("success.jsp");

}
/**
* 处理微信服务器发来的消息
*/
public void doPost(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
//消息的接受、处理、响应
request.setCharacterEncoding("utf-8");
response.setCharacterEncoding("utf-8");
//调用核心业务类型接受消息、处理消息
String respMessage = AccountsService.processRequest(request);

//响应消息
PrintWriter out = response.getWriter();
out.print(respMessage);
out.close();

}

public void init() throws ServletException {
// Put your code here
}

}

2）、SignUtil.java类，请求校验工具类，token需要和微信中填写的token一致

package cn.jon.wechat.utils;

import java.security.MessageDigest;
import java.security.NoSuchAlgorithmException;
import java.util.Arrays;
import java.util.Iterator;
import java.util.Map;
import java.util.Set;
import java.util.concurrent.ConcurrentHashMap;

/**
* 请求校验工具类
* @author jon
*/
public class SignUtil {
//与微信配置中的的Token一致
private static String token = "";

public static boolean checkSignature(String signature, String timestamp,
String nonce) {
String[] arra = new String[]{token,timestamp,nonce};
//将signature,timestamp,nonce组成数组进行字典排序
Arrays.sort(arra);
StringBuilder sb = new StringBuilder();
for(int i=0;i<arra.length;i++){
sb.append(arra[i]);
}
MessageDigest md = null;
String stnStr = null;
try {
md = MessageDigest.getInstance("SHA-1");
byte[] digest = md.digest(sb.toString().getBytes());
stnStr = byteToStr(digest);
} catch (NoSuchAlgorithmException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
//释放内存
sb = null;
//将sha1加密后的字符串与signature对比，标识该请求来源于微信
return stnStr!=null?stnStr.equals(signature.toUpperCase()):false;
}
/**
* 将字节数组转换成十六进制字符串
* @param digestArra
* @return
*/
private static String byteToStr(byte[] digestArra) {
// TODO Auto-generated method stub
String digestStr = "";
for(int i=0;i<digestArra.length;i++){
digestStr += byteToHexStr(digestArra[i]);
}
return digestStr;
}
/**
* 将字节转换成为十六进制字符串
*/
private static String byteToHexStr(byte dByte) {
// TODO Auto-generated method stub
char[] Digit = {'0','1','2','3','4','5','6','7','8','9','A','B','C','D','E','F'};
char[] tmpArr = new char[2];
tmpArr[0] = Digit[(dByte>>>4)&0X0F];
tmpArr[1] = Digit[dByte&0X0F];
String s = new String(tmpArr);
return s;
}

public static void main(String[] args) {
/*byte dByte = 'A';
System.out.println(byteToHexStr(dByte));*/
Map<String,String> map = new ConcurrentHashMap<String, String>();
map.put("4", "zhangsan");
map.put("100", "lisi");
Set set = map.keySet();
Iterator iter = set.iterator();
while(iter.hasNext()){
// String keyV = (String) iter.next();
String key =(String)iter.next();
System.out.println(map.get(key));
// System.out.println(map.get(iter.next()));
}
/*for(int i=0;i<map.size();i++){

}*/
}
}

3）、AccountsService.java服务类，主要是消息的请求和响应处理，并且当用户关注你的公众号的时候，可以设置默认推送消息

package cn.jon.wechat.service;

import java.util.Date;
import java.util.Map;

import javax.servlet.http.HttpServletRequest;

import cn.jon.wechat.message.req.ImageMessage;
import cn.jon.wechat.message.req.LinkMessage;
import cn.jon.wechat.message.req.LocationMessage;
import cn.jon.wechat.message.req.VideoMessage;
import cn.jon.wechat.message.req.VoiceMessage;
import cn.jon.wechat.message.resp.TextMessage;
import cn.jon.wechat.utils.MessageUtil;

/**
* 解耦，使控制层与业务逻辑层分离开来，主要处理请求，响应
* @author jon
*/
public class AccountsService {

public static String processRequest(HttpServletRequest request) {
String respMessage = null;
//默认返回的文本消息内容
String respContent = "请求处理异常，请稍后尝试！";
try {
//xml请求解析
Map<String,String> requestMap = MessageUtil.pareXml(request);

//发送方账号（open_id）
String fromUserName = requestMap.get("FromUserName");
//公众账号
String toUserName = requestMap.get("ToUserName");
//消息类型
String msgType = requestMap.get("MsgType");

//默认回复此文本消息
TextMessage defaultTextMessage = new TextMessage();
defaultTextMessage.setToUserName(fromUserName);
defaultTextMessage.setFromUserName(toUserName);
defaultTextMessage.setCreateTime(new Date().getTime());
defaultTextMessage.setMsgType(MessageUtil.MESSSAGE_TYPE_TEXT);
defaultTextMessage.setFuncFlag(0);
// 由于href属性值必须用双引号引起，这与字符串本身的双引号冲突，所以要转义
defaultTextMessage.setContent("欢迎访问<a href=\"http://blog.csdn.net/j086924\">jon的博客</a>!");
// defaultTextMessage.setContent(getMainMenu());
// 将文本消息对象转换成xml字符串
respMessage = MessageUtil.textMessageToXml(defaultTextMessage);

//文本消息
if(msgType.equals(MessageUtil.MESSSAGE_TYPE_TEXT)){
//respContent = "Hi,您发送的是文本消息！";
//回复文本消息
TextMessage textMessage = new TextMessage();
// textMessage.setToUserName(toUserName);
// textMessage.setFromUserName(fromUserName);
//这里需要注意，否则无法回复消息给用户了
textMessage.setToUserName(fromUserName);
textMessage.setFromUserName(toUserName);
textMessage.setCreateTime(new Date().getTime());
textMessage.setMsgType(MessageUtil.MESSSAGE_TYPE_TEXT);
textMessage.setFuncFlag(0);
respContent = "Hi，你发的消息是："+requestMap.get("Content");
textMessage.setContent(respContent);
respMessage = MessageUtil.textMessageToXml(textMessage);
}
//图片消息
else if(msgType.equals(MessageUtil.MESSSAGE_TYPE_IMAGE)){

ImageMessage imageMessage=new ImageMessage();
imageMessage.setToUserName(fromUserName);
imageMessage.setFromUserName(toUserName);
imageMessage.setCreateTime(new Date().getTime());
imageMessage.setMsgType(MessageUtil.MESSSAGE_TYPE_IMAGE);
//respContent=requestMap.get("PicUrl");
imageMessage.setPicUrl("http://img24.pplive.cn//2013//07//24//12103112092_230X306.jpg");
respMessage = MessageUtil.imageMessageToXml(imageMessage);
}
//地理位置
else if(msgType.equals(MessageUtil.MESSSAGE_TYPE_LOCATION)){
LocationMessage locationMessage=new LocationMessage();
locationMessage.setToUserName(fromUserName);
locationMessage.setFromUserName(toUserName);
locationMessage.setCreateTime(new Date().getTime());
locationMessage.setMsgType(MessageUtil.MESSSAGE_TYPE_LOCATION);
locationMessage.setLocation_X(requestMap.get("Location_X"));
locationMessage.setLocation_Y(requestMap.get("Location_Y"));
locationMessage.setScale(requestMap.get("Scale"));
locationMessage.setLabel(requestMap.get("Label"));
respMessage = MessageUtil.locationMessageToXml(locationMessage);

}

//视频消息
else if(msgType.equals(MessageUtil.MESSSAGE_TYPE_VIDEO)){
VideoMessage videoMessage=new VideoMessage();
videoMessage.setToUserName(fromUserName);
videoMessage.setFromUserName(toUserName);
videoMessage.setCreateTime(new Date().getTime());
videoMessage.setMsgType(MessageUtil.MESSSAGE_TYPE_VIDEO);
videoMessage.setMediaId(requestMap.get("MediaId"));
videoMessage.setThumbMediaId(requestMap.get("ThumbMediaId"));
respMessage = MessageUtil.videoMessageToXml(videoMessage);

}
//链接消息
else if(msgType.equals(MessageUtil.MESSSAGE_TYPE_LINK)){
LinkMessage linkMessage=new LinkMessage();
linkMessage.setToUserName(fromUserName);
linkMessage.setFromUserName(toUserName);
linkMessage.setCreateTime(new Date().getTime());
linkMessage.setMsgType(MessageUtil.MESSSAGE_TYPE_LINK);
linkMessage.setTitle(requestMap.get("Title"));
linkMessage.setDescription(requestMap.get("Description"));
linkMessage.setUrl(requestMap.get("Url"));
respMessage = MessageUtil.linkMessageToXml(linkMessage);
}
//语音消息
else if(msgType.equals(MessageUtil.MESSSAGE_TYPE_VOICE)){
VoiceMessage voiceMessage=new VoiceMessage();
voiceMessage.setToUserName(fromUserName);
voiceMessage.setFromUserName(toUserName);
voiceMessage.setCreateTime(new Date().getTime());
voiceMessage.setMsgType(MessageUtil.MESSSAGE_TYPE_VOICE);
voiceMessage.setMediaId(requestMap.get("MediaId"));
voiceMessage.setFormat(requestMap.get("Format"));
respMessage = MessageUtil.voiceMessageToXml(voiceMessage);
}
//事件推送
else if(msgType.equals(MessageUtil.MESSSAGE_TYPE_EVENT)){
//事件类型
String eventType = requestMap.get("Event");
//订阅
if(eventType.equals(MessageUtil.EVENT_TYPE_SUBSCRIBE)){
 respContent = "谢谢关注！";
}
//取消订阅
else if(eventType.equals(MessageUtil.EVENT_TYPE_UNSUBSCRIBE)){
 //
 System.out.println("取消订阅");

}
else if(eventType.equals(MessageUtil.EVENT_TYPE_CLICK)){
 //自定义菜单消息处理
 System.out.println("自定义菜单消息处理");
}
}

} catch (Exception e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
return respMessage;
}

public static String getMainMenu()
{
StringBuffer buffer =new StringBuffer();
buffer.append("您好，我是jon,请回复数字选择服务:").append("\n");
buffer.append("1、我的博客").append("\n");
buffer.append("2、 歌曲点播").append("\n");
buffer.append("3、 经典游戏").append("\n");
buffer.append("4 、聊天打牌").append("\n\n");
buffer.append("回复"+"0"+"显示帮助菜单");
return buffer.toString();

}
}

4）、MessageUtil.java帮助类，包括常量的定义和xml消息转换和处理

package cn.jon.wechat.utils;

import java.io.InputStream;
import java.io.Writer;
import java.util.HashMap;
import java.util.List;
import java.util.Map;

import javax.servlet.http.HttpServletRequest;

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

import cn.jon.wechat.message.req.ImageMessage;
import cn.jon.wechat.message.req.LinkMessage;
import cn.jon.wechat.message.req.LocationMessage;
import cn.jon.wechat.message.req.VideoMessage;
import cn.jon.wechat.message.req.VoiceMessage;
import cn.jon.wechat.message.resp.Article;
import cn.jon.wechat.message.resp.MusicMessage;
import cn.jon.wechat.message.resp.NewsMessage;
import cn.jon.wechat.message.resp.TextMessage;

import com.thoughtworks.xstream.XStream;
import com.thoughtworks.xstream.core.util.QuickWriter;
import com.thoughtworks.xstream.io.HierarchicalStreamWriter;
import com.thoughtworks.xstream.io.xml.PrettyPrintWriter;
import com.thoughtworks.xstream.io.xml.XppDriver;

/**
* 各种消息的处理类
* @author jon
*/

public class MessageUtil {
/**
* 文本类型
*/
public static final String MESSSAGE_TYPE_TEXT = "text";
/**
* 音乐类型
*/
public static final String MESSSAGE_TYPE_MUSIC = "music";
/**
* 图文类型
*/
public static final String MESSSAGE_TYPE_NEWS = "news";

/**
* 视频类型
*/
public static final String MESSSAGE_TYPE_VIDEO = "video";
/**
* 图片类型
*/
public static final String MESSSAGE_TYPE_IMAGE = "image";
/**
* 链接类型
*/
public static final String MESSSAGE_TYPE_LINK = "link";
/**
* 地理位置类型
*/
public static final String MESSSAGE_TYPE_LOCATION = "location";
/**
* 音频类型
*/
public static final String MESSSAGE_TYPE_VOICE = "voice";
/**
* 推送类型
*/
public static final String MESSSAGE_TYPE_EVENT = "event";
/**
* 事件类型：subscribe（订阅）
*/
public static final String EVENT_TYPE_SUBSCRIBE = "subscribe";
/**
* 事件类型：unsubscribe（取消订阅）
*/
public static final String EVENT_TYPE_UNSUBSCRIBE = "unsubscribe";
/**
* 事件类型：click（自定义菜单点击事件）
*/
public static final String EVENT_TYPE_CLICK= "CLICK";

/**
* 解析微信发来的请求 XML
*/
@SuppressWarnings("unchecked")
public static Map<String,String> pareXml(HttpServletRequest request) throws Exception {

//将解析的结果存储在HashMap中
Map<String,String> reqMap = new HashMap<String, String>();

//从request中取得输入流
InputStream inputStream = request.getInputStream();
//读取输入流
SAXReader reader = new SAXReader();
Document document = reader.read(inputStream);
//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();
//遍历所有的子节点取得信息类容
for(Element elem:elementList){
reqMap.put(elem.getName(),elem.getText());
}
//释放资源
inputStream.close();
inputStream = null;

return reqMap;
}
/**
* 响应消息转换成xml返回
* 文本对象转换成xml
*/
public static String textMessageToXml(TextMessage textMessage) {
xstream.alias("xml", textMessage.getClass());
return xstream.toXML(textMessage);
}
/**
* 语音对象的转换成xml
*
*/
public static String voiceMessageToXml(VoiceMessage voiceMessage) {
xstream.alias("xml", voiceMessage.getClass());
return xstream.toXML(voiceMessage);
}

/**
* 视频对象的转换成xml
*
*/
public static String videoMessageToXml(VideoMessage videoMessage) {
xstream.alias("xml", videoMessage.getClass());
return xstream.toXML(videoMessage);
}

/**
* 音乐对象的转换成xml
*
*/
public static String musicMessageToXml(MusicMessage musicMessage) {
xstream.alias("xml", musicMessage.getClass());
return xstream.toXML(musicMessage);
}
/**
* 图文对象转换成xml
*
*/
public static String newsMessageToXml(NewsMessage newsMessage) {
xstream.alias("xml", newsMessage.getClass());
xstream.alias("item", new Article().getClass());
return xstream.toXML(newsMessage);
}

/**
* 图片对象转换成xml
*
*/

public static String imageMessageToXml(ImageMessage imageMessage)
{
xstream.alias("xml",imageMessage.getClass());
return xstream.toXML(imageMessage);

}

/**
* 链接对象转换成xml
*
*/

public static String linkMessageToXml(LinkMessage linkMessage)
{
xstream.alias("xml",linkMessage.getClass());
return xstream.toXML(linkMessage);

}

/**
* 地理位置对象转换成xml
*
*/

public static String locationMessageToXml(LocationMessage locationMessage)
{
xstream.alias("xml",locationMessage.getClass());
return xstream.toXML(locationMessage);

}

/**
* 拓展xstream，使得支持CDATA块
*
*/
private static XStream xstream = new XStream(new XppDriver(){
public HierarchicalStreamWriter createWriter(Writer out){
return new PrettyPrintWriter(out){
//对所有的xml节点的转换都增加CDATA标记
boolean cdata = true;

@SuppressWarnings("unchecked")
public void startNode(String name,Class clazz){
 super.startNode(name,clazz);
}

protected void writeText(QuickWriter writer,String text){
 if(cdata){
 writer.write("<![CDATA[");
 writer.write(text);
 writer.write("]]>");
 }else{
 writer.write(text);
 }
}
};
}
});

}

5）、BaseMessage.java消息基类(包括：开发者微信号、用户账户、创建时间、消息类型、消息ID变量)，文本、视频、图片消息都会继承此基类，在此基础上扩展自己的变量，可根据开发者文档中的各种消息属性进行定义

package cn.jon.wechat.message.req;
/**
* 消息基类 （普通用户-公众号）
* @author jon
*/
public class BaseMessage {

//开发者微信号
private String ToUserName;
//发送方账号（一个openId）
private String FromUserName;
//消息创建时间（整型）
private long CreateTime;
//消息类型（text/image/location/link...）
private String MsgType;
//消息id 64位整型
private String MsgId;

public BaseMessage() {
super();
// TODO Auto-generated constructor stub
}

public BaseMessage(String toUserName, String fromUserName, long createTime,
String msgType, String msgId) {
super();
ToUserName = toUserName;
FromUserName = fromUserName;
CreateTime = createTime;
MsgType = msgType;
MsgId = msgId;
}

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 getMsgId() {
return MsgId;
}

public void setMsgId(String msgId) {
MsgId = msgId;
}
}

6）、TextMessage.java文本消息，继承自5中基类，扩展内容属性

package cn.jon.wechat.message.req;
/**
* 文本消息
* @author jon
*/
public class TextMessage extends BaseMessage{
//消息内容
private String content;

public String getContent() {
return content;
}

public void setContent(String content) {
this.content = content;
}

}

7）、ImageMessage.java图片消息 

package cn.jon.wechat.message.req;
/**
* 图片消息
* @author jon
*/
public class ImageMessage extends BaseMessage{
//图片链接
private String PicUrl;

public String getPicUrl() {
return PicUrl;
}

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

8）、VideoMessage.java视频消息

package cn.jon.wechat.message.req;

public class VideoMessage extends BaseMessage {

private String mediaId;
private String thumbMediaId;
public String getMediaId() {
return mediaId;
}
public void setMediaId(String mediaId) {
this.mediaId = mediaId;
}
public String getThumbMediaId() {
return thumbMediaId;
}
public void setThumbMediaId(String thumbMediaId) {
this.thumbMediaId = thumbMediaId;
}

}

其他消息类可根据开发者文档自行进行完成，另外，开发者也可以申请公众平台测试账号，对开发的相关内容进行测试。

本文已被整理到了《Android微信开发教程汇总》，《java微信开发教程汇总》欢迎大家学习阅读。