DWR基础入门使用-第一节

来源：互联网发布：linux双系统安装教程编辑：程序博客网时间：2024/06/06 09:04

1.功能目的：

这个系列是想通过DWR最终实现服务器到客户端的推送，形象描述类似于在页面不刷新的前提下，页面会接收到服务器推送给当前用户的消息，以气泡形式展现。

2.为何使用DWR：

这里可以参考我博客中的其他文章，很大部门摘自于网络。十分感谢这些具备分享精神的同仁们。我这里就不详细阐述了。

3.DWR学习的一些相关资料：

官网地址：

http://directwebremoting.org/dwr/

其实针对于DWR的学习，官网已经给了非常详尽的资料了。在线demo，简单的部署教程以及API等等非常详细了。

学习demo下载地址：http://download.csdn.net/download/techbirds_bao/5505799

4.helloword的dwr基础入门

目录结构：

步骤

1.jar包导入

2.web.xml配置

<web-app id="dwr">  <display-name>DWR (Direct Web Remoting)</display-name>  <description>A Simple Demo DWR</description>  <servlet>    <servlet-name>dwr-invoker</servlet-name>    <display-name>DWR Servlet</display-name>    <description>Direct Web Remoter Servlet</description>    <servlet-class>org.directwebremoting.servlet.DwrServlet</servlet-class>    <!-- This should NEVER be present in live -->    <init-param>      <param-name>debug</param-name>      <param-value>true</param-value>    </init-param>    <!-- Remove this unless you want to use active reverse ajax -->    <init-param>      <param-name>activeReverseAjaxEnabled</param-name>      <param-value>true</param-value>    </init-param>    <!-- By default DWR creates application scope objects when they are first    used. This creates them when the app-server is started -->    <init-param>      <param-name>initApplicationScopeCreatorsAtStartup</param-name>      <param-value>true</param-value>    </init-param>    <!-- This enables full streaming mode. It's probably better to leave this    out if you are running across the internet -->    <init-param>      <param-name>maxWaitAfterWrite</param-name>      <param-value>-1</param-value>    </init-param>    <!--    For more information on these parameters, see:    - http://getahead.org/dwr/server/servlet    - http://getahead.org/dwr/reverse-ajax/configuration    -->    <load-on-startup>1</load-on-startup>  </servlet>  <servlet-mapping>    <servlet-name>dwr-invoker</servlet-name>    <url-pattern>/dwr/*</url-pattern>  </servlet-mapping></web-app>

3.dwr.xml配置

<?xml version="1.0" encoding="UTF-8"?><!DOCTYPE dwr PUBLIC "-//GetAhead Limited//DTD Direct Web Remoting 2.0//EN" "http://getahead.org/dwr/dwr20.dtd"><dwr>  <allow><!-- base --><create creator="new" javascript="Say" scope="application">      <param name="class" value="org.getahead.dwrdemo.base.Say"/>    </create>  </allow></dwr>

4.dwr后台调用java类编写

package org.getahead.dwrdemo.base;public class Say {public String hello(){return "hello";}public String world(){return "world";}}

5.页面调用

<%@ page language="java" contentType="text/html; charset=UTF-8"    pageEncoding="UTF-8"%><!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd"><html><head><meta http-equiv="Content-Type" content="text/html; charset=UTF-8"><title>dwr基础使用</title><script type='text/javascript' src='../dwr/engine.js'> </script><script type='text/javascript' src='../dwr/interface/Say.js'> </script><script type='text/javascript' src='../dwr/util.js'> </script></head><body onload="dwr.engine.setActiveReverseAjax(true);"><input type="button" value="say hello" onclick="sayHello();"/><br/><input type="button" value="say world" onclick="sayWorld();"/></body><script type="text/javascript">function sayHello(){Say.hello(function(data){alert(data);});}function sayWorld(){Say.world(function(data){alert(data);});}</script></html>