前言：
有很多类似股票、外汇、期货等实时行情这种应用，客户端需要显示行情牌价等信息。
目前的作法是：客户端定时向服务器请求，无论数据是否有更新，都把数据发到客户端。
我们这里讲的一种技术不同以上这个做法，我们是采用服务器向客户端推的这种方式，该方式的好处不言自明。blazeds中有一个名为：StreamingAMFChannel 的通道，我们就是采用它来实现向客户端推这个功能。
Tick.java :
package test;
import java.math.BigDecimal;
import java.util.Date;
public class Tick {
??? private BigDecimal askPrice;
??? private BigDecimal bidPrice;
??? private BigDecimal midPrice;
??? private Date tickTime;
??? private String seqno;
??? public String getSeqno() {
??????? return seqno;
??? }
??? public void setSeqno(String seqno) {
??????? this.seqno = seqno;
??? }
??? public BigDecimal getAskPrice() {
??????? return askPrice;
??? }
??? public void setAskPrice(BigDecimal askPrice) {
??????? this.askPrice = askPrice;
??? }
??? public BigDecimal getBidPrice() {
??????? return bidPrice;
??? }
??? public void setBidPrice(BigDecimal bidPrice) {
??????? this.bidPrice = bidPrice;
??? }
??? public BigDecimal getMidPrice() {
??????? return midPrice;
??? }
??? public void setMidPrice(BigDecimal midPrice) {
??????? this.midPrice = midPrice;
??? }
??? public Date getTickTime() {
??????? return tickTime;
??? }
??? public void setTickTime(Date tickTime) {
??????? this.tickTime = tickTime;
??? }
}
FeedThread .java :
public static class FeedThread extends Thread {
? private String uid;
??
??????? public void setUid(String uid) {
?? this.uid = uid;
? }
? public FeedThread(String uid){
???????? this.uid = uid;
??????? }
??????? public boolean running = true;
??????? public void run() {
??????????? MessageBroker msgBroker = MessageBroker.getMessageBroker(null);
??????????? String clientID = UUIDUtils.createUUID();
??????????? int i = 0;
??????????? while (running) {
??????????????? Tick tick = new Tick();
??????????????? tick.setAskPrice(new BigDecimal("100"));
??????????????? tick.setBidPrice(new BigDecimal("100"));
??????????????? tick.setMidPrice(new BigDecimal("100"));
??????????????? tick.setTickTime(new Date());
??????????????? tick.setSeqno(String.valueOf(i));
??????????????? System.out.println(i+"--"+uid);
???????????????
??????????????? AsyncMessage msg = new AsyncMessage();
??????????????? msg.setDestination("tick-data-feed");
??????????????? msg.setHeader("DSSubtopic","tick"+uid);
??????????????? msg.setClientId(clientID);
??????????????? msg.setMessageId(UUIDUtils.createUUID());
??????????????? msg.setTimestamp(System.currentTimeMillis());
????????????????
??????????????? msg.setBody(tick);
????????????????
??????????????? msgBroker.routeMessageToService(msg,null);
???????????????
??????????????? i++;
??????????????? try {
??????????????????? Thread.sleep(20);
??????????????? } catch (InterruptedException e) {
??????????????? }
??????????? }
??????? }
??? }
UserService.java :
package sws.service;
import module.User;
public interface UserService {
? public void Test(String uid);
? public void stop(String uid);
}
UserServiceImpl.java :
import java.util.HashMap;
import java.util.Map;
import org.springframework.beans.factory.annotation.Autowired;
import sws.dao.UserDao;
import test.TickServlet.FeedThread;
public class UserServiceImpl implements UserService {
?private static Map<String,Thread> map = new HashMap<String,Thread>();
?public void Test(String uid) {
?? Boolean b = map.containsKey(uid);
?? if(!b){
?? FeedThread thread = new FeedThread(uid);
?? thread.start();
?? map.put(uid,thread);
?? }
?}
?public void stop(String uid) {
? FeedThread thread = (FeedThread)map.get(uid);
? thread.running = false;
?}
}
下一步加入flex配置文件。
flex的配置文件默认有四个，文件目录在WebContentWEB-INFflex目录下。
messaging-config.xml
proxy-config.xml
remoting-config.xml
services-config.xml
其实，这中间用的是一个，就是services-config.xml，只是在services-config.xml中，包含其它三个。
在services-config.xml文件中，加入如下：
??????? <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>
messaging-config.xml文件中，加入如下：
??? <destination id="tick-data-feed">
??????? <properties>
??????????? <server>
??????????????? <allow-subtopics>true</allow-subtopics>
??????????????? <subtopic-separator>.</subtopic-separator>
??????????? </server>
??????? </properties>
??????? <channels>
??????????? <channel ref="my-polling-amf" />
??????????? <channel ref="my-streaming-amf" />
??????? </channels>
??? </destination>
Tick.as文件内容如下：
//Tick.as
package
??? {
??? [RemoteClass(alias="test.Tick")]
??? [Bindable]
??? public class Tick
??? {????????
??????? public var askPrice:Number;
??????? public var bidPrice:Number;
??????? public var midPrice:Number;
??????? public var tickTime:Date;;
??????? public var seqno:String;
??? }
????
}
再在main.mxml文件中，加入如下代码：
<?xml version="1.0" encoding="utf-8"?>
<mx:Application xmlns:mx="http://www.adobe.com/2006/mxml" layout="absolute" viewSourceURL="srcview/index.html" height="378" width="426">
??? <mx:Script>
??????? <![CDATA[
??????????? import mx.controls.Alert;
??????????? import mx.rpc.events.ResultEvent;
??????????? import mx.rpc.events.FaultEvent;
??????????? import mx.messaging.Consumer;
??????????? import mx.messaging.Channel;
??????????? import mx.messaging.ChannelSet;
??????????? import mx.messaging.events.MessageEvent;
????????????
??????????? [Bindable]
??????????? public var tick:Tick;
??????????? public function postUrl():void {
//?????????????
//???????????? httpservice.url = "http://localhost:8080/test/servlet/TickServlet?cmd=start&uid="+telId.text;
//??????????????? httpservice.send();
//??????????????? httpservice.addEventListener(ResultEvent.RESULT,resultHandler);
//??????????????? httpservice.addEventListener(FaultEvent.FAULT,faultHandler);
???????? user.Test(telId.text);
??????????? }
??????????? public function resultHandler(event:ResultEvent):void{
??????????????? submsg();
????????????? }
??????????? public function faultHandler(event:FaultEvent):void{
??????????????? trace(event.fault);
????????????? }
??????????? public function submsg():void
??????????? {??
??????????????
??????????????? var consumer:Consumer = new Consumer();
??????????????? consumer.destination = "tick-data-feed";
??????????????? consumer.subtopic = "tick"+telId.text;
??????????????? consumer.channelSet = new ChannelSet(["my-streaming-amf"]);
??????????????? consumer.addEventListener(MessageEvent.MESSAGE,messageHandler);
??????????????? consumer.subscribe();
??????????? }
????????????
??????????? private function messageHandler(event:MessageEvent):void?
??????????? {
???????????????? tick = event.message.body as Tick;
?????????????
??????????????? txtTick.text = tick.seqno;
??????????? }
??????????? private function stop():void {
???????????? user.stop(telId.text);
??????????? }
??????? ]]>
??? </mx:Script>
??? //RemoteObject 的方式远程调用java类 userService在rremoting-config.xml中配置 ??? <mx:RemoteObject id="user" destination="userService" source="userService" result="resultHandler(event)"/> ??? <mx:HTTPService id="httpservice" /> ??? <mx:Panel x="32" y="43" width="362" height="302" layout="absolute" title="Watch Tick"> ??????? <mx:Label x="72" y="43" text="Label" id="txtTick"/> ??????? <mx:Button x="132" y="41" label="start" click="postUrl(); "/> ??????? <mx:TextInput? id="telId"? x="37" y="83"/>//标识用户 ??????? <mx:Button label="stop" click="stop();" x="216" y="41"/> ??? </mx:Panel> </mx:Application>
