微信开发之消息接收--文本消息(五)

一、消息格式

 <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>

参数	描述
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

二、编写消息类实体，代码如下：

     BaseMessage.java   ---基础消息类

package com.weixin.message;

/**
 * 消息实体类
 * @author Code猿猿
 *
 */
public class BaseMessage {
	
	/**
	 * 开发者微信号
	 */
	public String ToUserName;
	/**
	 * 发送方帐号（一个OpenID）
	 */
	public String FromUserName;
	/**
	 * 消息创建时间 （整型）
	 */
	public long CreateTime;
	/**
	 * text
	 */
	public String MsgType ;
	
	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;
	}
	
}

　　TextMessage.java  ---文本消息

package com.weixin.message;

/**
 * 文本消息
 * @author Zhangsy
 *
 */
public class TextMessage extends BaseMessage {

	/**
	 * 文本消息内容
	 */
	public String Content;
	/**
	 * 消息id，64位整型
	 */
	public long MsgId ;
	
	public String getContent() {
		return Content;
	}
	public void setContent(String content) {
		Content = content;
	}
	public long getMsgId() {
		return MsgId;
	}
	public void setMsgId(long msgId) {
		MsgId = msgId;
	}
	
}

三、编写消息类（读取xml）

     MessageUtil.java  --》解析接收的xml信息、封装返回的xml信息

     注意：这里用到了2个JAR包：xstream-1.3.jar、dom4j.jar

package com.weixin.util;

import java.io.IOException;
import java.io.InputStream;
import java.io.Writer;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import java.util.regex.Pattern;

import javax.servlet.http.HttpServletRequest;

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

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;
import com.weixin.message.TextMessage;

/**
 * 对消息的处理
 * @author Code猿猿
 *
 */
public class MessageUtil {
	
	
	/**
	 * text
	 */
	public static final String RESP_MESSAGE_TYPE_TEXT = "text";

	/**
	 * music
	 */
	public static final String RESP_MESSAGE_TYPE_MUSIC = "music";

	/**
	 * news
	 */
	public static final String RESP_MESSAGE_TYPE_NEWS = "news";

	/**
	 * text
	 */
	public static final String REQ_MESSAGE_TYPE_TEXT = "text";

	/**
	 * image
	 */
	public static final String REQ_MESSAGE_TYPE_IMAGE = "image";

	/**
	 * link
	 */
	public static final String REQ_MESSAGE_TYPE_LINK = "link";

	/**
	 * location
	 */
	public static final String REQ_MESSAGE_TYPE_LOCATION = "location";

	/**
	 * voice
	 */
	public static final String REQ_MESSAGE_TYPE_VOICE = "voice";
	
	/**
	 * video
	 */
	public static final String REQ_MESSAGE_TYPE_VIDEO = "video";
	
	/**
	 * shortvideo
	 */
	public static final String REQ_MESSAGE_TYPE_SHORTVIDEO = "shortvideo";

	/**
	 * event
	 */
	public static final String REQ_MESSAGE_TYPE_EVENT = "event";

	/**
	 * subscribe
	 */
	public static final String EVENT_TYPE_SUBSCRIBE = "subscribe";

	/**
	 * unsubscribe
	 */
	public static final String EVENT_TYPE_UNSUBSCRIBE = "unsubscribe";

	/**
	 * CLICK
	 */
	public static final String EVENT_TYPE_CLICK = "CLICK";
	
	
	
	public static Map<String,String> parseXml(HttpServletRequest request){
		
		Map<String,String> messageMap=new HashMap<String, String>();
		
		InputStream inputStream=null;
		try {
			//读取request Stream信息
			inputStream=request.getInputStream();
		} catch (IOException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		}
		
		SAXReader reader = new SAXReader();
		Document document=null;
		try {
			document = reader.read(inputStream);
		} catch (DocumentException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		}
		
		Element root=document.getRootElement();
		List<Element> elementsList=root.elements();
		
		for(Element e:elementsList){
			messageMap.put(e.getName(),e.getText());
		}
		try {
			inputStream.close();
			inputStream=null;
		} catch (IOException e1) {
			// TODO Auto-generated catch block
			e1.printStackTrace();
		}
		
		return messageMap;
	}
	
	
	/**
	 * 转换文本消息
	 * 
	 * @param textMessage
	 *           
	 * @return xml
	 */
	public static String textMessageToXml(TextMessage textMessage) {
		xstream.alias("xml", textMessage.getClass());
		return xstream.toXML(textMessage);
	}

	/**
	 * 
	 * 定义xstream让value自动加上CDATA标签
	 */
	private static XStream xstream = new XStream(new XppDriver() {
		public HierarchicalStreamWriter createWriter(Writer out) {
			return new PrettyPrintWriter(out) {
				boolean cdata = false;
				@SuppressWarnings("unchecked")
				public void startNode(String name, Class clazz) {

					if (!name.equals("xml")) {
						char[] arr = name.toCharArray();
						if (arr[0] >= 'a' && arr[0] <= 'z') {
							// arr[0] -= 'a' - 'A';
							arr[0] = (char) ((int) arr[0] - 32);
						}
						name = new String(arr);
					}

					super.startNode(name, clazz);

				}

				@Override
				public void setValue(String text) {

					if (text != null && !"".equals(text)) {
						Pattern patternInt = Pattern
								.compile("[0-9]*(\.?)[0-9]*");
						Pattern patternFloat = Pattern.compile("[0-9]+");
						if (patternInt.matcher(text).matches()
								|| patternFloat.matcher(text).matches()) {
							cdata = false;
						} else {
							cdata = true;
						}
					}
					super.setValue(text);
				}

				protected void writeText(QuickWriter writer, String text) {

					if (cdata) {
						writer.write("<![CDATA[");
						writer.write(text);
						writer.write("]]>");
					} else {
						writer.write(text);
					}
				}
			};
		}

	});
	

}

四、修改Servlet中的Post方法，加入如下代码：

/**
	 * @see HttpServlet#doPost(HttpServletRequest request, HttpServletResponse response)
	 */
	protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
		
		
		request.setCharacterEncoding("UTF-8");
		response.setCharacterEncoding("UTF-8");
		
		Map<String,String> message=MessageUtil.parseXml(request);
		
		String messageType=message.get("MsgType");
		
		if(messageType.equals(MessageUtil.REQ_MESSAGE_TYPE_TEXT)){
			//接收的是文本消息
			
			//打印接收所有参数
			System.out.println("ToUserName："+message.get("ToUserName"));
			System.out.println("FromUserName："+message.get("FromUserName"));
			System.out.println("CreateTime："+message.get("CreateTime"));
			System.out.println("MsgType："+message.get("MsgType"));
			System.out.println("Content："+message.get("Content"));
			System.out.println("MsgId："+message.get("MsgId"));
			
			String req_content=message.get("Content");
			
			String res_content="";
			
			//组装回复消息 
			//我们做个小实验
			//接收内容：你好  回复：你好
			//接收内容：大家好  回复：大家好
			//接收内容：同志们好  回复：为人民服务
			if("你好".equals(req_content)){
				res_content="你好";
			}else if ("大家好".equals(req_content)){
				res_content="大家好";
			}else if("同志们好".equals(req_content)){
				res_content="为人民服务";
			}else{
				//否则原样输出输入内容
				res_content=req_content;
			}
			
			TextMessage textMessage=new TextMessage();
			textMessage.setToUserName(message.get("FromUserName"));   //这里的ToUserName  是刚才接收xml中的FromUserName
			textMessage.setFromUserName(message.get("ToUserName"));   //这里的FromUserName 是刚才接收xml中的ToUserName  这里一定要注意，否则会出错
			textMessage.setCreateTime(new Date().getTime());
			textMessage.setContent(res_content);
			textMessage.setMsgType(messageType);
			
			String xml=MessageUtil.textMessageToXml(textMessage);
			
			System.out.println("xml:"+xml);
			
			PrintWriter out = response.getWriter();
			out.print(xml);
		    out.close();
		}

五、部署测试

向公众号发送信息，看是否能够正常返回信息。

给各位推荐一个在线测试的平台：http://debug.fangbei.org/

操作步骤：

录入我们接入微信平台的URL和TOKEN

选择消息类型：文本

内容：输入要发送给公众号的内容

在右侧可看到效果的预览。