package com.dev.trade.service;
            import java.util.HashSet;
            import java.util.List;
            import java.util.Set;
            import java.util.Collections;
            import com.dev.trade.bo.Stock;
            public class StockQuoteGenerator {
            private StockService ss = new StockService();
            private List<Stock>  stocks = null;
            private static StockQuoteGenerator generator = new StockQuoteGenerator();
            private Set<QuoteListener>
            listeners = Collections.synchronizedSet(new HashSet<QuoteListener> ());
            private volatile boolean contextDestroyed = false;
            private StockQuoteGenerator() {
            Runnable r = new Runnable() {
            public void run() {
            try {
            while (!contextDestroyed) {
            update(generateStockQuotes());
            Thread.sleep(5000);
            }
            }catch (Exception e) {
            e.printStackTrace(System.out);
            }
            }
            };
            Thread t = new Thread(r);
            t.setDaemon(true);
            t.start();
            }
            public static StockQuoteGenerator getInstance() {
            return generator;
            }
            public void setContextDestroyed(boolean cd) {
            this.contextDestroyed = cd;
            }
            public void addListener(QuoteListener listener) {
            listeners.add(listener);
            }
            private void update(List<Stock>  stocks) {
            for (QuoteListener listener : listeners) {
            listener.updateStockQuotes(stocks);
            }
            }
            private List<Stock>  generateStockQuotes() {
            stocks = ss.getStocks();
            return stocks;
            }
            }
            

            public void updateStockQuotes(List<Stock> stocks) {
            ScriptBuffer script = new ScriptBuffer();
            script.appendScript("updateStocks(").appendData(stocks).appendScript(
            ");");
            Collection<ScriptSession> sessions = wctx.getAllScriptSessions();
            for (ScriptSession session : sessions) {
            if(!session.isInvalidated()){
            session.addScript(script);
            } else {
            wctx.getAllScriptSessions().remove(session);
            }
            }
            }
            

            <dwr>
            <allow>
            <create creator="new" javascript="Ticker" scope="application">
            <param name="class" value="com.dev.trade.service.StockQuoteListenerImpl"/>
            </create>
            <create creator="new" javascript="StockService" scope="application">
            <param name="class" value="com.dev.trade.service.StockService"/>
            </create>
            <convert converter="bean" match="com.dev.trade.bo.Stock"/>
            </allow>
            </dwr>
            

            <?xml version="1.0" encoding="UTF-8"?>
            <web-app xmlns="http://java./xml/ns/j2ee" version="2.4"
            xmlns:xsi="http://www./2001/XMLSchema-instance"
            xsi:schemaLocation="http://java./xml/ns/j2ee
            http://java./xml/ns/j2ee/web-app_2_4.xsd">
            <display-name>brokerage</display-name>
            <listener>
            <listener-class>
            com.dev.trade.listener.DwrContextListener
            </listener-class>
            </listener>
            <servlet>
            <display-name>DWR Servlet</display-name>
            <servlet-name>dwr-invoker</servlet-name>
            <servlet-class>org.directwebremoting.servlet.DwrServlet</servlet-class>
            <init-param>
            <param-name>debug</param-name>
            <param-value>true</param-value>
            </init-param>
            <init-param>
            <param-name>activeReverseAjaxEnabled</param-name>
            <param-value>true</param-value>
            </init-param>
            <init-param>
            <param-name>initApplicationScopeCreatorsAtStartup</param-name>
            <param-value>true</param-value>
            </init-param>
            <load-on-startup>1</load-on-startup>
            </servlet>
            <servlet-mapping>
            <servlet-name>dwr-invoker</servlet-name>
            <url-pattern>/dwr/*</url-pattern>
            </servlet-mapping>
            <welcome-file-list>
            <welcome-file>/stocks.html</welcome-file>
            </welcome-file-list>
            </web-app>
            

            <script type="text/javascript" src="dwr/engine.js"></script>
            <script type='text/javascript'
            src='/brokerage/dwr/interface/StockService.js'></script>
            

            function getModel(stocks) {
            var data = new Array();
            for ( var i = 0; i < stocks.length; i++) {
            var subData = new Array();
            subData[0] = stocks[i].symbol;
            subData[1] = stocks[i].companyName
            subData[2] = stocks[i].price
            subData[3] = stocks[i].eps
            data[i] = subData;
            }
            updatedModel = new dojox.grid.data.Table(null, data);
            return updatedModel;
            }
            

            <script type="text/javascript" src="/dojo/dojo/dojo.js"
            djConfig="isDebug:false, parseOnLoad: true"></script>
            

            var view1 = {
            noscroll :false,
            cells : [ [ {
            name :'Symbol',
            width :'auto'
            }, {
            name :'Company Name',
            width :'auto'
            }, {
            name :'Price',
            width :'auto'
            }, {
            name :'Earnings Per Share',
            width :'auto'
            } ] ]
            };
            var gridLayout = [ {
            type :'dojox.GridRowView',
            width :'20px'
            }, view1 ];
            <div class="tundra" id="stock_grid" dojoType="dojox.Grid" model="updatedModel"
            structure="gridLayout" elasticView="1" defaultHeight="37em"></div>