使用DWR的操作步骤：
我是用spring与dwr融合的方式的来使用dwr的.
第一步 导入dwr.jar (version: 2.0.5)
第二步 配置web.xml文件
第三步 配置dwr.xml
第四步 编写js代码
第五步 页面引用
在WEB-INF下建立dwr.xml
<?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="Test">
<param name="class" value="com.Test"/>
<include method="">//java类的方法名
</create>
<create creator="spring" javascript="userService">
<param name="beanName" value="userService">
//比如spring在applicationContext.xml中的beanid为userService
<include method="">
</allow>
</dwr>
接着在web.xml中加入DWRServlet配置
<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>
<init-param>
<param-name>logLevel</param-name>
<param-value>DEBUG</param-value>
</init-param>
</servlet>
<servlet-mapping>
<servlet-name>dwr-invoker</servlet-name>
<url-pattern>
/dwr/*
</url-pattern>
//此处是在项目运行用到dwr后生成脚本的所在的目录，以后用的时候根据相对路径引入。
</servlet-mapping>
接着创建java类
package com;
public class.Test{
public String getArea(String city)
{
StringBuffer sb=new StringBuffer("");
sb.append("<select name='area' style='width:120'>");
sb.append("<option value='0'>全部</option>");
if(city.equals("aaa"))
{
sb.append("<option value='111>111</option>");
sb.append("<option value='222>222</option>");
sb.append("<option value='333>333</option>");
}
if(city.equals("bbb"))
{
sb.append("<option value='444>444</option>");
sb.append("<option value='555>555</option>");
}
if(city.equals("ccc"))
{
sb.append("<option value='666>666</option>");
sb.append("<option value='777'>777</option>");
}
sb.append("</select>");
return sb.toString();
}
}
建立test.jsp
<%@ page language="java" contentType="text/html; charset=GBK"%>
<title>dwr.jsp</title>
<meta http-equiv="pragma" content="no-cache">
<meta http-equiv="cache-control" content="no-cache">
<meta http-equiv="expires" content="0">
<meta http-equiv="keywords" content="keyword1,keyword2,keyword3">
<meta http-equiv="description" content="This is my page">
<script type='text/javascript' src='dwr/interface/Test.js'></script>
<script type='text/javascript' src='dwr/engine.js'></script>
<script type='text/javascript' src='dwr/util.js'></script>
<script language="javascript">
function update() {
var city = document.getElementById("city").value;
Test.getArea(city, function(data) {
document.getElementById("demoReply").innerHTML=data;
});
}
</script>
<body>
<p>
Name:
<select style="width:120" id="city" name="city" οnchange="update()">
<option value="aaa">aaa</option>
<option value="bbb">bbb</option>
<option value="ccc">ccc</option>
</select>
<span id="demoReply">
<select style="width:120" id="area" name="area">
<option value="0">全部</option>
</select>
</span>
</p>
</body>
大家照着上面的例子，把这个项目发布，运行http://localhost:8080/项目名/test.jsp就看到效果了
