使用您的公众账号登陆http://mp.weixin.qq.com/，选择菜单--高级功能-开发模式--查看文档，即能看到微信公众平台目前所能开发的功能。
2.实现GET方法
从文档中知道，我们需要实现POST和GET方法，GET方法用于验证微信和你的通讯验证，POST用于消息处理。
新建Servlet HelloWeChat，先实现其中的GET方法
protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
// TODO 为了简单起见,先不对消息来源进行校验
response.setContentType("text/html;charset=UTF-8");
PrintWriter pw = response.getWriter();
String echo = request.getParameter("echostr");
echo = new String(echo.getBytes("ISO-8859-1"),"UTF-8");
pw.println(echo);
}可以在本地使用http://localhost:8080/QiyadengWeb/HelloWeChat?echostr=hello中文，先进行测试，如果没有问题，可以部署到服务器上，然后在微信公众平台进行设置了。
3.实现POST方法
POST方法首先接收到微信公众平台传送过来的XML，从中提取消息发送人和消息内容。更加消息发送内容，你可以增加自己的处理逻辑，最后拼装成回复消息XML，返回给微信公众平台。
protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
response.setContentType("text/html;charset=UTF-8");
PrintWriter pw = response.getWriter();
String wxMsgXml = IOUtils.toString(request.getInputStream(),"utf-8");
WeChatTextMessage textMsg = null;
try {
textMsg = getWeChatTextMessage(wxMsgXml);
} catch (Exception e) {
e.printStackTrace();
}
StringBuffer replyMsg = new StringBuffer();
if(textMsg != null){
//增加你所需要的处理逻辑，这里只是简单重复消息
replyMsg.append("您给我的消息是：");
replyMsg.append(textMsg.getContent());
}
else{
replyMsg.append(":)不是文本的消息，我暂时看不懂");
}
String returnXml = getReplyTextMessage(replyMsg.toString(), textMsg.getFromUserName());
pw.println(returnXml);
}关于调试，这里推荐一个工具Fiddler，你可以模拟微信的POST消息到你的本地，而不必每次部署到服务器上进行调试。关于Fiddler的POST数据使用方法，可以参考下图标注内容。
5.依赖库
使用maven的同学，添加以下依赖即可。非maven用户，找到这些库添加到buider path中即可。
joda-time joda-time 2.2 org.apache.commons commons-io 1.3.2 com.thoughtworks.xstream xstream 1.4.3
6.完整的代码
package com.qiyadeng.wechat;
import java.io.IOException;
import java.io.PrintWriter;
import java.util.Date;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import org.apache.commons.io.IOUtils;
import com.thoughtworks.xstream.XStream;
import com.thoughtworks.xstream.io.xml.DomDriver;
/**
* Servlet implementation class HelloWeChat
*/
public class HelloWeChat extends HttpServlet {
private static final long serialVersionUID = 1L;
/**
* @see HttpServlet#HttpServlet()
*/
public HelloWeChat() {
super();
}
/**
* @see HttpServlet#doGet(HttpServletRequest request, HttpServletResponse response)
*/
protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
// TODO 为了简单起见,先不对消息来源进行校验
response.setContentType("text/html;charset=UTF-8");
PrintWriter pw = response.getWriter();
String echo = request.getParameter("echostr");
echo = new String(echo.getBytes("ISO-8859-1"),"UTF-8");
pw.println(echo);
}
/**
* @see HttpServlet#doPost(HttpServletRequest request, HttpServletResponse response)
*/
protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
response.setContentType("text/html;charset=UTF-8");
PrintWriter pw = response.getWriter();
String wxMsgXml = IOUtils.toString(request.getInputStream(),"utf-8");
WeChatTextMessage textMsg = null;
try {
textMsg = getWeChatTextMessage(wxMsgXml);
} catch (Exception e) {
e.printStackTrace();
}
StringBuffer replyMsg = new StringBuffer();
if(textMsg != null){
//增加你所需要的处理逻辑，这里只是简单重复消息
replyMsg.append("您给我的消息是：");
replyMsg.append(textMsg.getContent());
}
else{
replyMsg.append(":)不是文本的消息，我暂时看不懂");
}
String returnXml = getReplyTextMessage(replyMsg.toString(), textMsg.getFromUserName());
pw.println(returnXml);
}
private WeChatTextMessage getWeChatTextMessage(String xml){
XStream xstream = new XStream(new DomDriver());
xstream.alias("xml", WeChatTextMessage.class);
xstream.aliasField("ToUserName", WeChatTextMessage.class, "toUserName");
xstream.aliasField("FromUserName", WeChatTextMessage.class, "fromUserName");
xstream.aliasField("CreateTime", WeChatTextMessage.class, "createTime");
xstream.aliasField("MsgType", WeChatTextMessage.class, "messageType");
xstream.aliasField("Content", WeChatTextMessage.class, "content");
xstream.aliasField("MsgId", WeChatTextMessage.class, "msgId");
WeChatTextMessage wechatTextMessage = (WeChatTextMessage)xstream.fromXML(xml);
return wechatTextMessage;
}
private String getReplyTextMessage(String content, String weChatUser){
WeChatReplyTextMessage we = new WeChatReplyTextMessage();
we.setMessageType("text");
we.setFuncFlag("0");
we.setCreateTime(new Long(new Date().getTime()).toString());
we.setContent(content);
we.setToUserName(weChatUser);
we.setFromUserName("shanghaiweather");//TODO 你的公众帐号微信号
XStream xstream = new XStream(new DomDriver());
xstream.alias("xml", WeChatReplyTextMessage.class);
xstream.aliasField("ToUserName", WeChatReplyTextMessage.class, "toUserName");
xstream.aliasField("FromUserName", WeChatReplyTextMessage.class, "fromUserName");
xstream.aliasField("CreateTime", WeChatReplyTextMessage.class, "createTime");
xstream.aliasField("MsgType", WeChatReplyTextMessage.class, "messageType");
xstream.aliasField("Content", WeChatReplyTextMessage.class, "content");
xstream.aliasField("FuncFlag", WeChatReplyTextMessage.class, "funcFlag");
String xml =xstream.toXML(we);
return xml;
}
}位置识别这是实际应用经常应用的消息，特别是很多商家，通过了解用户位置，给用户提供特别的产品或是商场的推荐。其中用户可能发送两种类型的消息：
1.微信地理位置信息
2.路名、标志性建筑或是商场名称
认识一下，微信地理位置消息，包含一些什么信息
1351776360 23.134521 113.358803 20 1234567890123456
包含的主要信息有经度纬度和Label的位置。可以根据label中描述的位置信息，提供给用户对应的服务。也可根据用户的经度纬度信息，提供你最近的产品或是有地域性的产品。
首先根据微信的地理位置信息，定义WeChatLocationMessage类，并能把Xml转换为WeChatLocationMessage对象
public class WeChatLocationMessage {
private String toUserName;
private String fromUserName;
private String createTime;
private String msgType;
private String locationx;
private String localtiony;
private String scale;
private String label;
private String msgId;
public static WeChatLocationMessage getWeChatLocationMessage(String xml){
XStream xstream = new XStream(new DomDriver());
WeChatLocationMessage message = null;
xstream.alias("xml", WeChatLocationMessage.class);
xstream.aliasField("ToUserName", WeChatLocationMessage.class, "toUserName");
xstream.aliasField("FromUserName", WeChatLocationMessage.class, "fromUserName");
xstream.aliasField("CreateTime", WeChatLocationMessage.class, "createTime");
xstream.aliasField("MsgType", WeChatLocationMessage.class, "msgType");
xstream.aliasField("Location_X", WeChatLocationMessage.class, "locationx");
xstream.aliasField("Location_Y", WeChatLocationMessage.class, "localtiony");
xstream.aliasField("Scale", WeChatLocationMessage.class, "scale");
xstream.aliasField("Label", WeChatLocationMessage.class, "label");
xstream.aliasField("MsgId", WeChatLocationMessage.class, "msgId");
message = (WeChatLocationMessage)xstream.fromXML(xml);
return message;
}
//getter and setter
}本文利用百度的地图API，查找最近的银行做为示例。
public String getPalace(String query,String lat,String lng) throws ClientProtocolException, IOException{
HttpClient httpClient = new DefaultHttpClient();
String url = palceRequestUrl(query,lat,lng);
logger.log(Level.INFO, url);
HttpGet httpget = new HttpGet(url);
ResponseHandler responseHandler = new BasicResponseHandler();
String responseBody = httpClient.execute(httpget, responseHandler);
logger.log(Level.INFO,"baidu response:"+responseBody);
return responseBody;
}
public String palceRequestUrl(String query,String lat,String lng) throws UnsupportedEncodingException {
String url = WeChatConstant.BASEURL + "place/search?query=" + URLEncoder.encode(query,"UTF-8") + "&key="
+ WeChatConstant.MAPKEY +"&location="+lat+","+lng +"&radius=2000"+"&output=" + WeChatConstant.OUTPUTFORMAT;
return url;
} 输出的结果
OK 中国工商银行东长安街支行 东城区东长安街1号东方广场西三办公楼1楼 39.915891 116.41867 a025683c73033c35a21de987 http://api.map.baidu.com/place/detail?uid=a025683c73033c35a21de987&output=html&source=placeapi 银行,王府井/东单
接下来，把百度地图反映出来的最近位置信息，以图文消息的格式展示给微信用户
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