Flex blazeds 向客户端推送数据

转自http://www.sloppy.cn/blog/article/247.htm 

网上已有例子，只转载下，按照网上配置会msgBroker为nullpoint的错，需要在web.xml中增加 MessageBroker Servlet的配置，在这记录。
<!-- MessageBroker Servlet -->
    <servlet>
        <servlet-name>pmportalMessageBrokerServlet</servlet-name>
        <display-name>MessageBrokerServlet</display-name>
        <servlet-class>flex.messaging.MessageBrokerServlet</servlet-class>
        <init-param>
            <param-name>services.configuration.file</param-name>
            <param-value>/WEB-INF/flex/services-config.xml</param-value>
       </init-param>
        <load-on-startup>1</load-on-startup>
    </servlet>

    <servlet-mapping>
        <servlet-name>pmportalMessageBrokerServlet</servlet-name>
        <url-pattern>/messagebroker/*</url-pattern>
    </servlet-mapping>


services-config.xml加入下面代码 
 
程序代码 
 
<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加入下面的代码 
 
程序代码 
 
<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> 
 
 
 
第三步：创建一个Servlet: 
 
程序代码 
 
package cn.bestwiz.design.tc.servlet; 
 
import java.io.IOException; 
import java.math.BigDecimal; 
import java.util.Date; 
 
import javax.servlet.ServletException; 
import javax.servlet.http.HttpServlet; 
import javax.servlet.http.HttpServletRequest; 
import javax.servlet.http.HttpServletResponse; 
 
import cn.bestwiz.design.tc.Tick; 
import flex.messaging.MessageBroker; 
import flex.messaging.messages.AsyncMessage; 
import flex.messaging.util.UUIDUtils; 
 
public class TickCacheServlet extends HttpServlet { 
 
    /**
     * 
     */ 
    private static final long serialVersionUID = 1L; 
    private static FeedThread thread; 
 
    @Override 
    protected void doGet(HttpServletRequest req, HttpServletResponse resp) 
            throws ServletException, IOException { 
 
        String cmd = req.getParameter("cmd"); 
        if (cmd.equals("start")) { 
            start(); 
        } 
        if (cmd.equals("stop")) { 
            stop(); 
        } 
    } 
 
    @Override 
    protected void doPost(HttpServletRequest req, HttpServletResponse resp) 
            throws ServletException, IOException { 
        // TODO Auto-generated method stub 
        super.doGet(req, resp); 
    } 
 
    @Override 
    public void destroy() { 
        // TODO Auto-generated method stub 
        super.destroy(); 
    } 
 
    @Override 
    public void init() throws ServletException { 
        // TODO Auto-generated method stub 
        super.init(); 
    } 
 
    public void start() { 
        if (thread == null) { 
            thread = new FeedThread(); 
            thread.start(); 
        } 
        System.out.println("start!!"); 
    } 
 
    public void stop() { 
        thread.running = false; 
        thread = null; 
    } 
 
    public static class FeedThread extends Thread { 
 
        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); 
 
                AsyncMessage msg = new AsyncMessage(); 
                msg.setDestination("tick-data-feed"); 
                msg.setHeader("DSSubtopic", "tick"); 
                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) { 
                } 
 
            } 
        } 
    } 
 
} 
 
 
 
第四步：创建一个Java类: 
 
程序代码 
 
package cn.bestwiz.design.tc; 
 
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; 
    } 
 
} 
 
 
 
 
第五步： 
配置Flex项目： 
Root Folder:C:\Program Files\Apache Software Foundation\Tomcat 6.0\webapps\blazeds 
Root URL:http://localhost:8080/blazeds 
Context Root:/blazeds 
 
第六步：创建AS类： 
 
程序代码 
 
package cn.sloppy 
{ 
    [RemoteClass(alias="cn.bestwiz.design.tc.Tick")] 
    [Bindable] 
    public class Tick 
    { 
        public function Tick() 
        { 
        } 
        public var askPrice:Number; 
        public var bidPrice:Number; 
        public var midPrice:Number; 
        public var tickTimeate;; 
        public var seqno:String; 
 
    } 
} 
 
 
第七步：Flex主程序代码 
 
程序代码 
 
// 
            import mx.controls.Alert; 
            import mx.rpc.events.ResultEvent; 
            import mx.messaging.Consumer; 
            import mx.messaging.Channel; 
            import mx.messaging.ChannelSet; 
            import mx.messaging.events.MessageEvent; 
            //  
[Bindable] 
            public var tick:Tick; 
public function submsg():void 
            { 
                Alert.show("click start"); 
                var consumer:Consumer = new Consumer(); 
                consumer.destination = "tick-data-feed"; 
                consumer.subtopic = "tick"; 
                consumer.channelSet = new ChannelSet(["my-streaming-amf"]); 
                consumer.addEventListener(MessageEvent.MESSAGE, messageHandler); 
                consumer.subscribe(); 
                Alert.show("click end"); 
            } 
             
            private function messageHandler(event:MessageEvent):void  
            { 
                var tick:Tick = event.message.body as Tick; 
                txtTick.text = tick.seqno; 
            } 
<mxanel x="524" y="47" width="362" height="302" layout="absolute" title="Watch Tick"> 
        <mxabel x="72" y="43" text="Label" id="txtTick"/> 
        <mx:Button x="132" y="41" label="Button" click="submsg(); "/> 
    </mxanel> 
 
 
第七步：运行Flex：http://localhost:8080/blazeds/HelloWorld-debug/HelloWorld.html?debug=true 
点击Button 
迂曲运行Servlet：http://localhost:8080/blazeds/TickCacheServlet?cmd=start 
再看看Flex的效果：是不是文字一直在增长？ 
恭喜。成功了。