DWR反向Ajax的一个简单Web聊天
<?xml version="1.0" encoding="GBK"?><web-app xmlns="http://java.sun.com/xml/ns/javaee"xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"xsi:schemaLocation="http://java.sun.com/xml/ns/javaeehttp://java.sun.com/xml/ns/javaee/web-app_2_5.xsd" version="2.5"><!-- 配置DWR的核心Servlet --><servlet><!-- 指定DWR核心Servlet的名字 --><servlet-name>dwr-invoker</servlet-name><!-- 指定DWR核心Servlet的实现类 --><servlet-class>org.directwebremoting.servlet.DwrServlet</servlet-class><!-- 指定DWR核心Servlet处于调试状态 --><init-param><param-name>debug</param-name><param-value>true</param-value></init-param><!-- 设置启用反向Ajax技术 --><init-param><param-name>pollAndCometEnabled</param-name><param-value>true</param-value></init-param><load-on-startup>1</load-on-startup></servlet><!-- 指定核心Servlet的URL映射 --><servlet-mapping><servlet-name>dwr-invoker</servlet-name><!-- 指定核心Servlet映射的URL --><url-pattern>/dwr/*</url-pattern></servlet-mapping></web-app>
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package com.lbx.dwr.chat;import java.util.Collection;import java.util.LinkedList;import org.directwebremoting.WebContext;import org.directwebremoting.WebContextFactory;import org.directwebremoting.proxy.dwr.Util;public class JavaChat{//保存聊天信息的List对象private LinkedList<ChatMsg> messages = new LinkedList<ChatMsg>();public void addMessage(String text){if (text != null && text.trim().length() > 0){messages.addFirst(new ChatMsg(text));//最多保留10条聊天记录while (messages.size() > 10){messages.removeLast();}}WebContext wctx = WebContextFactory.get();//以当前WebContext关联的ScriptSession创建UtilUtil utilThis = new Util(wctx.getScriptSession());//使用utilThis清除text文本框的内容utilThis.setValue("text", "");//获取当前页面的urlString currentPage = wctx.getCurrentPage();//获取正在浏览当前页的所有浏览器会话Collection sessions = wctx.getScriptSessionsByPage(currentPage);//以sessions创建Util对象Util utilAll = new Util(sessions);//删除chatlog列表里的所有列表项utilAll.removeAllOptions("chatlog");//使用messages集合里集合元素的text属性为chatlog添加列表项utilAll.addOptions("chatlog" , messages , "text");}}?
package com.lbx.dwr.chat;public class ChatMsg{//ChatMsg包装的字符串private String text;public ChatMsg(){}public ChatMsg(String text){this.text = text;}//text属性的setter和gette方法public void setText(String text){this.text = text;}public String getText(){return text;}}?
<%@ page language="java" import="java.util.*" pageEncoding="UTF-8"%><%String path = request.getContextPath();String basePath = request.getScheme() + "://"+ request.getServerName() + ":" + request.getServerPort()+ path + "/";%><!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN""http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd"><html xmlns="http://www.w3.org/1999/xhtml"><head><title>反向Ajax的聊天室</title><meta name="website" content="http://www.crazyit.org" /><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/chat.js'></script><script type='text/javascript' src='dwr/util.js'></script><script type="text/javascript">function sendMessage(){//调用远程Java方法，无需回调函数chat.addMessage(dwr.util.getValue("text"));}</script></head><!-- 本页面启用反向Ajax --><body onload="dwr.engine.setActiveReverseAjax(true);"><h3>反向Ajax的聊天室</h3><div style="width: 460px; height: 200px; border: 1px solid #999999"><ul id="chatlog"></ul></div><br />输入您的聊天信息:<input id="text" onkeypress="dwr.util.onReturn(event, sendMessage);"/><input type="button" value="发送" onclick="sendMessage()" /></body></html>?
<?xml version="1.0" encoding="UTF-8"?><!DOCTYPE dwr PUBLIC "-//GetAhead Limited//DTD Direct Web Remoting 2.0//EN""http://getahead.ltd.uk/dwr/dwr20.dtd"><dwr><allow><create creator="new" javascript="chat" scope="application"><param name="class" value="com.lbx.dwr.chat.JavaChat"/></create><convert converter="bean" match="com.lbx.dwr.chat.ChatMsg"/> </allow></dwr>
?转自:http://550516671-qq-com.iteye.com/blog/831838