dwr 写的小程序，配置

第一、在web.xml里面有如下配置：

<?xml version="1.0" encoding="UTF-8"?>
<web-app  xmlns="http://java.sun.com/xml/ns/j2ee" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://java.sun.com/xml/ns/j2ee http://java.sun.com/xml/ns/j2ee/web-app_2_4.xsd" version="2.4">

    <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>
    </servlet>

    <servlet-mapping>
        <servlet-name>dwr-invoker</servlet-name>
        <url-pattern>/dwr/*</url-pattern>
    </servlet-mapping>

</web-app>

第二，在web.xml同目录下添加一个dwr.xml文件：javascript 唯一，作为jsp页面的引用

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE dwr PUBLIC "-//GetAhead Limited//DTD Direct Web Remoting 2.0//EN" "http://www.getahead.ltd.uk/dwr/dwr20.dtd">

<dwr>
<allow>
    <create creator="new" javascript="Hello" >
       <param name="class" value="com.hoo.entity.Message"/>
    </create>
</allow>
</dwr>

第三，写一个java类

package com.hoo.entity;

public class Message {
    
    public String hello(String name) {
        return "这是" + name + "的第一个dwr";
    }

}

第四，写jsp页面

<%@ 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 HTML 4.01 Transitional//EN">
<html>
  <head>
    <base href="<%=basePath%>">
    
    <title>Chat</title>
    
    <meta http-equiv="pragma" content="no-cache">
    <meta http-equiv="cache-control" content="no-cache">
    <meta http-equiv="expires" content="0">    
    <script type="text/javascript" src="${pageContext.request.contextPath}/dwr/engine.js"></script>
    <script type="text/javascript" src="${pageContext.request.contextPath}/dwr/util.js"></script>
    <script type="text/javascript" src="${pageContext.request.contextPath}/dwr/interface/Hello.js"></script>
    <%--<script type="text/javascript" src="chat.js"> </script>
   --%><script type="text/javascript">
   function hello() {
           var user = document.getElementById("user").value;
        //var user = $('user').value;
        Hello.hello(user, callback);
        }
 
        function callback(msg) {
           DWRUtil.setValue('result', msg);
}
   </script>

  </head>
  
  <body>
    <input id="user" type="text" />
     <input type='button' value='你好' onclick='hello();' /> 
  <jsp:useBean id="abc" class="com.hoo.entity.Message"></jsp:useBean>
  <jsp:getProperty property="str" name="abc"/>
 <div id="result"></div>
  </body>
</html>

要记得在项目中添加的包有：commons-logging.jar dwr.jar log4j.jar