DWR3.0框架入门(1) —— 实现ajax

框架简介:DWR(Direct Web Remoting)
     是一个用于改善web页面与Java类交互的远程服务器端Ajax开源框架,可以帮助开发人员开发包含AJAX技术的网站。它可以允许在浏览器里的代码使用运行在WEB服务器上的JAVA函数,就像它就在浏览器里一样。
 
本Demo实现的基本功能:
点击jsp界面的按钮,通过DWR调用到服务器端的java代码,在控制台打印出jsp输入框中的值
 
Demo构建流程:
 
1.新建Web工程
 
2.导入jar包:commons-logging-x.x.x.jar和dwr3.0.jar
 

3.在web.xml中加入DWR使用能力:

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<servlet
        <servlet-name> dwr-invoker </servlet-name
        <servlet-class> uk.ltd.getahead.dwr.DWRServlet</servlet-class >
        <init-param
            <param-name> debug</param-name >
            <param-value> true</param-value >
        </init-param>
        <init-param>
            <param-name> crossDomainSessionSecurity</param-name >
            <param-value> false</param-value >
        </init-param>
        <init-param>
            <param-name> allowScriptTagRemoting</param-name >
            <param-value> true</param-value >
        </init-param>
</servlet>
<servlet-mapping
        <servlet-name> dwr-invoker </servlet-name
        <url-pattern>/dwr/*</ url-pattern>
</servlet-mapping>
4.在src中新建类MessagePush:
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package sugar.dwr;
 
public class MessagePush {
 
        public void send(String str){
              System. out.println(str);
       }
}
5.与web.xml同级目录下创建dwr.xml,用来配置js函数与java代码的映射关系:
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<?xml version="1.0" encoding= "UTF-8"?>
<!DOCTYPE dwr PUBLIC "-//GetAhead Limited//DTD Direct Web Remoting 3.0//EN" "http://getahead.org/dwr/dwr30.dtd" >
<dwr
        <allow
               <create creator="new" javascript= "messagePush">
                      <param name="class" >sugar.dwr.MessagePush</ param>
               </create>
        </allow
</dwr>
6.在index.jsp中写入js逻辑(该处使用到jquery,请自行添加):
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<%@ page language= "java" import ="java.util.*" pageEncoding="UTF-8" %>
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html>
  <head >
    <title >DWR</ title>
    <script type= "text/javascript" src ="js/jquery-1.8.3.js"></ script>
    <script type= "text/javascript" src ="dwr/util.js"></ script>  
        <script type="text/javascript" src= "dwr/engine.js"></script >
        <script type="text/javascript" src= "dwr/interface/messagePush.js" ></script>
  </head >
  <body >
        <table border="0" >
               <tr>
                      <td>< input id ="content" type="text" /></td>
                      <td>< input id ="send" type="button" value= "send"/></td >
               </tr>
        </table>
        <script type="text/javascript" >
              $( "#send").click(function(){
                      var content = $("#content" ).val();
                     messagePush.send(content);
              });
        </script>
  </body >
</html>
说明:jsp文件中必须引入几个js,它们都是隐含存在的,不用考虑它们在哪儿。其中engine.js和util.js是固定的。另外的一个js的名称就是dwr.xml中配置的类名。

测试结果:

DWR3.0框架入门(1) —— 实现ajax

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