日期:2014-05-17  浏览次数:20707 次

初学DWR(版本为DWR3)自已写了个polling的demo不成功,有些问题弄不明白
注:版本前提为DWR3,使用polling
dwr.xml
<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE dwr PUBLIC "-//GetAhead Limited//DTD Direct Web Remoting 3.0//EN" "http://getahead.org/dwr/dwr3.0.dtd">
<dwr>
  <allow>
  <create creator="new" scope="application">
  <param name="class" value="com.example.dwr.reverseajax.Test"/>
  </create>
  </allow>
</dwr>

web.xml
<?xml version="1.0" encoding="ISO-8859-1"?>
<!DOCTYPE web-app PUBLIC
  "-//Sun Microsystems, Inc.//DTD Web Application 2.3//EN"
  "http://java.sun.com/dtd/web-app_2_3.dtd">
<web-app id="dwr">
  <listener>
  <listener-class>org.directwebremoting.servlet.DwrListener</listener-class>
  </listener>
  <servlet>
  <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>
  <!-- polling模式 -->
  <init-param>
  <param-name>activeReverseAjaxEnabled</param-name>
  <param-value>true</param-value>
  </init-param>
  <init-param>
  <param-name>org.directwebremoting.extend.ServerLoadMonitor</param-name>  
  <param-value>org.directwebremoting.impl.PollingServerLoadMonitor</param-value>  
  </init-param>
  <init-param>
  <param-name>disconnectedTime</param-name>
  <param-value>5000</param-value>
  </init-param>
  </servlet>
  <servlet-mapping>
  <servlet-name>dwr-invoker</servlet-name>
  <url-pattern>/dwr/*</url-pattern>
  </servlet-mapping>
</web-app>


Test.java
package com.example.dwr.reverseajax;


import org.directwebremoting.Browser;
import org.directwebremoting.ui.dwr.Util;

public class Test 
{
  public void start() 
  {
   
  Browser.withCurrentPage(new Runnable() 
  {
  public void run() 
  {
  Util.setValue("chatlog", "<h1>"+System.currentTimeMillis()+"</h1>");
  }
  });
  }
}

index.jsp
<!DOCTYPE html>
<html>
<head>
  <meta http-equiv="Content-Type" content="text/html; charset=UTF-8" />
  <script type='text/javascript' src='dwr/engine.js'> </script>
  <script type='text/javascript' src='dwr/interface/Test.js'> </script>
  <script type='text/javascript' src='dwr/util.js'> </script>
  <script type="text/javascript">
  dwr.engine.setNotifyServerOnPageUnload(true);
  Test.start();
  
  </script>
 </head>
<body onload="dwr.engine.setActiveReverseAjax(true);">
  <hr/>
  <ul id="chatlog"></ul>
</body