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  • Flex数据推送

    文介绍怎样使用Flex数据推送实现前台消息订阅，是在前面Flex+BlazeDS+Spring整合基础上进行的，利用Spring来简化配置。环境准备：

                    1.完成Flex+BlazeDS+Spring整合

                    2.修改项目根目录下.flexProperties文件中serverContextRoot为项目名，否则后台接收不到前台订阅信息(此处浪费了我很多时间，一定注意)

            修改配置文件

            1.修改WEB-INF/flex/services-config.xml，添加如下代码：

    [html] view plaincopyprint?
    1. <channel-definitionid="my-streaming-amf"class="mx.messaging.channels.StreamingAMFChannel"> 
    2.     <endpointurl="http://{server.name}:{server.port}/{context.root}/messagebroker/streamingamf"class="flex.messaging.endpoints.StreamingAMFEndpoint"/> 
    3.     <properties> 
    4.         <idle-timeout-minutes>0</idle-timeout-minutes> 
    5.         <max-streaming-clients>10</max-streaming-clients> 
    6.         <server-to-client-heartbeat-millis>5000</server-to-client-heartbeat-millis> 
    7.         <user-agent-settings> 
    8.             <user-agentmatch-on="MSIE"kickstart-bytes="2048"max-streaming-connections-per-session="1"/> 
    9.             <user-agentmatch-on="Firefox"kickstart-bytes="2048"max-streaming-connections-per-session="1"/> 
    10.         </user-agent-settings> 
    11.     </properties> 
    12. </channel-definition>  
    <channel-definition id="my-streaming-amf" class="mx.messaging.channels.StreamingAMFChannel">
	<endpoint url="http://{server.name}:{server.port}/{context.root}/messagebroker/streamingamf" class="flex.messaging.endpoints.StreamingAMFEndpoint"/>
	<properties>
		<idle-timeout-minutes>0</idle-timeout-minutes>
		<max-streaming-clients>10</max-streaming-clients>
		<server-to-client-heartbeat-millis>5000</server-to-client-heartbeat-millis>
		<user-agent-settings>
			<user-agent match-on="MSIE" kickstart-bytes="2048" max-streaming-connections-per-session="1"/>
			<user-agent match-on="Firefox" kickstart-bytes="2048" max-streaming-connections-per-session="1"/>
		</user-agent-settings>
	</properties>
</channel-definition>

            2.修改Spring配置文件applicationContext.xml，把<flex:message-broker/>替换为如下代码：

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    1.     <!-- allow-subtopics设为true，允许订阅者订阅指定主题消息 --> 
    2.     <flex:message-destinationid="data_push"allow-subtopics="true"subtopic-separator="."/> 
    3. <flex:message-broker> 
    4.     <flex:message-servicedefault-channels="my-streaming-amf,my-polling-amf"/> 
    5. </flex:message-broker> 
    6.      
    7.     <beanid="messageTemplate"class="org.springframework.flex.messaging.MessageTemplate"/>  
     	<!-- allow-subtopics设为true，允许订阅者订阅指定主题消息 -->
 	<flex:message-destination id="data_push" allow-subtopics="true" subtopic-separator="."/>
	<flex:message-broker>
		<flex:message-service default-channels="my-streaming-amf,my-polling-amf"/>
	</flex:message-broker>
 	
 	<bean id="messageTemplate" class="org.springframework.flex.messaging.MessageTemplate" />

    其中"my-streaming-amf,my-polling-amf"要在services-config.xml中配置，messageTemplate在代码中实现推送功能。

            后台推送数据

            1.添加推送数据Service，代码如下，注意msg设置的各参数，前后台及配置文件都要对应

    [java] view plaincopyprint?
    1. package demo.flex.service; 
    2.  
    3. import javax.annotation.Resource; 
    4.  
    5. import org.springframework.flex.messaging.AsyncMessageCreator; 
    6. import org.springframework.flex.messaging.MessageTemplate; 
    7. import org.springframework.stereotype.Service; 
    8.  
    9. import flex.messaging.messages.AsyncMessage; 
    10. import flex.messaging.util.UUIDUtils; 
    11.  
    12. @Service 
    13. publicclass DataPushService { 
    14.  
    15.     @Resource 
    16.     private MessageTemplate messageTemplate; 
    17.      
    18.     publicvoid push(String topic, Object data) { 
    19.         messageTemplate.send(new CustomAsyncMessageCreator(topic, data)); 
    20.     } 
    21.      
    22.     class CustomAsyncMessageCreator implements AsyncMessageCreator { 
    23.          
    24.         private String topic; 
    25.         private Object data; 
    26.          
    27.         public CustomAsyncMessageCreator(String topic, Object data) { 
    28.             this.topic = topic; 
    29.             this.data = data; 
    30.         } 
    31.          
    32.         @Override 
    33.         public AsyncMessage createMessage() { 
    34.             AsyncMessage msg = new AsyncMessage(); 
    35.              
    36.             msg.setClientId(UUIDUtils.createUUID()); 
    37.             msg.setMessageId(UUIDUtils.createUUID()); 
    38.             msg.setTimestamp(System.currentTimeMillis()); 
    39.             msg.setDestination("data_push");    // 必须和配置文件中message-destination相同 
    40.             msg.setHeader("DSSubtopic", topic); // 设置订阅主题 
    41.             msg.setBody(data); 
    42.              
    43.             return msg; 
    44.         } 
    45.     } 
    46. }  
    package demo.flex.service;

import javax.annotation.Resource;

import org.springframework.flex.messaging.AsyncMessageCreator;
import org.springframework.flex.messaging.MessageTemplate;
import org.springframework.stereotype.Service;

import flex.messaging.messages.AsyncMessage;
import flex.messaging.util.UUIDUtils;

@Service
public class DataPushService {

	@Resource
	private MessageTemplate messageTemplate;
	
	public void push(String topic, Object data) {
		messageTemplate.send(new CustomAsyncMessageCreator(topic, data));
	}
	
	class CustomAsyncMessageCreator implements AsyncMessageCreator {
		
		private String topic;
		private Object data;
		
		public CustomAsyncMessageCreator(String topic, Object data) {
			this.topic = topic;
			this.data = data;
		}
		
		@Override
		public AsyncMessage createMessage() {
			AsyncMessage msg = new AsyncMessage();
			
			msg.setClientId(UUIDUtils.createUUID());
			msg.setMessageId(UUIDUtils.createUUID());
			msg.setTimestamp(System.currentTimeMillis());
			msg.setDestination("data_push");	// 必须和配置文件中message-destination相同
			msg.setHeader("DSSubtopic", topic);	// 设置订阅主题
			msg.setBody(data);
			
			return msg;
		}
	}
}

            2.添加控制数据开始推送及结束推送Controller，每隔一秒推送当前系统时间

    [java] view plaincopyprint?
    1. package demo.flex.mvc; 
    2.  
    3. import java.text.SimpleDateFormat; 
    4. import java.util.Date; 
    5.  
    6. import javax.annotation.Resource; 
    7.  
    8. import org.springframework.stereotype.Controller; 
    9. import org.springframework.web.bind.annotation.RequestMapping; 
    10.  
    11. import demo.flex.service.DataPushService; 
    12.  
    13. @Controller 
    14. publicclass DataPush { 
    15.  
    16.     privatestatic FeedThread thread; 
    17.      
    18.     @Resource 
    19.     private DataPushService dataPushService; 
    20.      
    21.     @RequestMapping("push") 
    22.     public String push(String cmd) throws Exception { 
    23.          
    24.         if ("start".equals(cmd)) { 
    25.             start(); 
    26.         } 
    27.         else { 
    28.             stop(); 
    29.         } 
    30.          
    31.         return"push"; 
    32.     } 
    33.      
    34.     privatevoid start() { 
    35.         if (thread == null) { 
    36.             thread = new FeedThread(); 
    37.             thread.start(); 
    38.         } 
    39.         System.out.println("开始数据推送..."); 
    40.     } 
    41.  
    42.     privatevoid stop() { 
    43.         thread.running = false; 
    44.         thread = null; 
    45.         System.out.println("结束数据推送..."); 
    46.     } 
    47.      
    48.     publicclass FeedThread extends Thread { 
    49.         publicboolean running = true; 
    50.         private SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss"); 
    51.  
    52.         publicvoid run() { 
    53.  
    54.             while (running) { 
    55.                 String time = sdf.format(new Date()); 
    56.                 System.out.println(">>>>>>>>>>>" + time); 
    57.                  
    58.                 // time为订阅主题 
    59.                 dataPushService.push("time", time); 
    60.                  
    61.                 try { 
    62.                     Thread.sleep(1000); 
    63.                 } catch (InterruptedException e) { 
    64.                 } 
    65.             } 
    66.         } 
    67.     } 
    68. }  
    package demo.flex.mvc;

import java.text.SimpleDateFormat;
import java.util.Date;

import javax.annotation.Resource;

import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.RequestMapping;

import demo.flex.service.DataPushService;

@Controller
public class DataPush {

	private static FeedThread thread;
	
	@Resource
	private DataPushService dataPushService;
	
	@RequestMapping("push")
	public String push(String cmd) throws Exception {
		
		if ("start".equals(cmd)) {
			start();
		}
		else {
			stop();
		}
		
		return "push";
	}
	
	private void start() {
		if (thread == null) {
			thread = new FeedThread();
			thread.start();
		}
		System.out.println("开始数据推送...");
	}

	private void stop() {
		thread.running = false;
		thread = null;
		System.out.println("结束数据推送...");
	}
	
	public class FeedThread extends Thread {
		public boolean running = true;
		private SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");

		public void run() {

			while (running) {
				String time = sdf.format(new Date());
				System.out.println(">>>>>>>>>>>" + time);
				
				// time为订阅主题
				dataPushService.push("time", time);
				
				try {
					Thread.sleep(1000);
				} catch (InterruptedException e) {
				}
			}
		}
	}
}

            3.为使DataPush能够正常运行，修改web.xml及applicationContext.xml配置，添加如下代码：

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    1. <!-- mvc mapping--> 
    2. <servlet-mapping> 
    3.     <servlet-name>Spring MVC Dispatcher Servlet</servlet-name> 
    4.     <url-pattern>/mvc/*</url-pattern> 
    5. </servlet-mapping>  
    	<!-- mvc mapping-->
	<servlet-mapping>
		<servlet-name>Spring MVC Dispatcher Servlet</servlet-name>
		<url-pattern>/mvc/*</url-pattern>
	</servlet-mapping>
    [html] view plaincopyprint?
    1. <mvc:annotation-driven/> 
    2. lt;bean class="org.springframework.web.servlet.view.InternalResourceViewResolver">   
    3. <propertyname="prefix"value="/WEB-INF/jsp/"/>   
    4. <propertyname="suffix"value=".jsp"/>  
    5. <propertyname="viewClass"value="org.springframework.web.servlet.view.JstlView"/> 
    6. lt;/bean>   
     	<mvc:annotation-driven />
	<bean class="org.springframework.web.servlet.view.InternalResourceViewResolver">  
		<property name="prefix" value="/WEB-INF/jsp/"/>  
		<property name="suffix" value=".jsp"/> 
		<property name="viewClass" value="org.springframework.web.servlet.view.JstlView" />
	</bean>

            前台订阅功能

            前台FlexDemo.mxml中添加如下代码，订阅主题为time的消息，用于显示后台系统时间

    [html] view plaincopyprint?
    1. <s:GrouphorizontalCenter="0"> 
    2.     <s:Labeltext="系统时间："/> 
    3.     <s:TextInputid="timeText"text="systime"editable="false"x="80"y="0"width="200"/> 
    4.     <s:Buttonlabel="显示时间"x="60"y="40"click="showTimeHandler(event)"/> 
    5.     <s:Buttonlabel="隐藏时间"x="155"y="40"click="hideTimeHandler(event)"/> 
    6. </s:Group>          
    		<s:Group horizontalCenter="0">
			<s:Label text="系统时间："/>
			<s:TextInput id="timeText" text="systime" editable="false" x="80" y="0" width="200"/>
			<s:Button label="显示时间" x="60" y="40" click="showTimeHandler(event)"/>
			<s:Button label="隐藏时间" x="155" y="40" click="hideTimeHandler(event)"/>
		</s:Group>
    [javascript] view plaincopyprint?
    1. privatevar consumer:Consumer; 
    2.  
    3. protectedfunction showTimeHandler(event:MouseEvent):void 
    4. { 
    5.     if (consumer == null) { 
    6.         consumer = new Consumer();  
    7.      
    8.         // consumer设置的参数要与后台配置对应 
    9.         consumer.destination = "data_push";  
    10.         consumer.channelSet = new ChannelSet(["my-streaming-amf","my-polling-amf"]); 
    11.          
    12.         // 只能收到主题为time的订阅消息 
    13.         consumer.subtopic = "time";  
    14.          
    15.         //添加message的监听，当后台有消息发送时，调用messageHandler  
    16.         consumer.addEventListener(MessageEvent.MESSAGE, messageHandler);  
    17.          
    18.         // 订阅 
    19.         consumer.subscribe(); 
    20.     } 
    21. } 
    22.  
    23. protectedfunction hideTimeHandler(event:MouseEvent):void 
    24. { 
    25.     if (consumer != null) { 
    26.          
    27.         // 取消订阅 
    28.         consumer.unsubscribe(); 
    29.         consumer.removeEventListener(MessageEvent.MESSAGE, messageHandler);  
    30.         consumer = null; 
    31.         timeText.text = "systime";  
    32.     } 
    33. } 
    34.  
    35. privatefunction messageHandler(event:MessageEvent):void  
    36. {  
    37.     var time:String = event.message.body as String;  
    38.     timeText.text = time;  
    39. }  
    			private var consumer:Consumer;
			
			protected function showTimeHandler(event:MouseEvent):void
			{
				if (consumer == null) {
					consumer = new Consumer(); 
				
					// consumer设置的参数要与后台配置对应
					consumer.destination = "data_push"; 
					consumer.channelSet = new ChannelSet(["my-streaming-amf","my-polling-amf"]);
					
					// 只能收到主题为time的订阅消息
					consumer.subtopic = "time"; 
					
					//添加message的监听，当后台有消息发送时，调用messageHandler 
					consumer.addEventListener(MessageEvent.MESSAGE, messageHandler); 
					
					// 订阅
					consumer.subscribe();
				}
			}
			
			protected function hideTimeHandler(event:MouseEvent):void
			{
				if (consumer != null) {
					
					// 取消订阅
					consumer.unsubscribe();
					consumer.removeEventListener(MessageEvent.MESSAGE, messageHandler); 
					consumer = null;
					timeText.text = "systime"; 
				}
			}

			private function messageHandler(event:MessageEvent):void 
			{ 
				var time:String = event.message.body as String; 
				timeText.text = time; 
			}

    消息订阅也可以采用MultiTopicProducer，能够在单个消息处理程序中同时订阅主题，通过addSubscription(topic)方法订阅主题，removeSubscription(topic)取消订阅。Consumer只能订阅单个主题。

            所有代码已写完，启动项目进行测试！

            1.订阅消息：打开链接http://localhost:8080/FlexDemo/FlexDemo.html，点击显示时间订阅time消息，点击隐藏时间取消订阅

            2.推送消息：打开链接http://localhost:8080/FlexDemo/mvc/push?cmd=start推送消息，http://localhost:8080/FlexDemo/mvc/push?cmd=stop停止推送

            经过测试，my-streaming-amf、my-polling-amf两个通道都可以实现消息推送订阅，但my-streaming-amf发送订阅请求后会一直维护这一个请求直到取消订阅，my-polling-amf会根据配置文件中设定的时间间隔，每过一段时间发送一次订阅请求，获得后台订阅的信息。

            最后附完整代码下载地址：http://download.csdn.net/detail/sjepy/5522399
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  • 原文地址：https://www.cnblogs.com/regalys168/p/3627732.html
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