ajax开源项目dwr的使用：
利用DWR可以在客户端利用JavaScript直接调用服务端的Java方法并返回值
给JavaScript就好像直接本地客户端调用一样.
1：下载dwr.jar文件，将其加入到web工程的lib下；
2：在web.xml文件中配置如下信息：
<servlet>
<servlet-name>dwr-invoker</servlet-name>
<servlet-class>uk.ltd.getahead.dwr.DWRServlet</servlet-class>
</servlet>
<servlet-mapping>
<servlet-name>dwr-invoker</servlet-name>
<url-pattern>/dwr/*</url-pattern>
</servlet-mapping>
其中url-pattern中必须配置为 “/dwr/* ”，不能为工程的名称！！
3：在web.xml同级中增加文件dwr.xml，此文件是javaScript中调用的方法，影射到class类
例如：
<!DOCTYPE dwr PUBLIC "-//GetAhead Limited//DTD Direct Web Remoting 2.0//EN" "http://www.getahead.ltd.uk/dwr//dwr20.dtd">
<dwr>
<!-- without allow, DWR isn't allowed to do anything -->
<allow>
<create creator="new" javascript="MyTest" scope="application">
<param name="class" value="com.test.ajax.DWRTest"/>
</create>
<create scope="application" creator="new" javascript="showData">
<param name="class" value="com.test.ajax.HelloName"/>
</create>
</allow>
</dwr>
在allow节点中定义要影射的class类，并且给其class类起一个javaScript的名字，以便在
javaScript中调用。
4：然后定义class文件
package com.test.ajax;
public class DWRTest
{
public DWRTest(){
}
public String getMyName(){
return "hello_ajax";
}
}
/**
*---------------------------------------------------
**/
package com.test.ajax;
public class HelloName
{
private String userName ;
public HelloName(){
}
/**
* @return Returns the userName.
*/
public String getUserName()
{
return "helloTest";
}
/**
* @param userName The userName to set.
*/
public void setUserName(String userName)
{
this.userName = userName;
}
}
5: 这时就可以在html或jsp中调用此class文件了，调用方式如下
一下为测试的 html文件
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html>
<head>
<title>DWR - My First AJAX</title>
<meta http-equiv="Content-Type" content="text/html; charset=gb2312">
<script type='text/javascript' src='dwr/interface/MyTest.js'></script>
<script type='text/javascript' src='dwr/interface/showData.js'></script>
<script type='text/javascript' src='dwr/engine.js'></script>
<script type='text/javascript' src='dwr/util.js'></script>
<script language="javascript">
var mycall=function callBack(data){
DWRUtil.setValue("demo1",data);
DWRUtil.setValue("demo2","leo_wang");
DWRUtil.setValue("userName",data);
}
function showMyName(){
//MyTest.getMyName(mycall);
showData.getUserName(mycall);
}
function clearName(){
demo1.value="";
demo2.value="";
}
</script>
</head>
<body>
<h1>Ajax Test Page</h1>
<input type="button" value="setMyName" onclick="javascript:showMyName()">
<input type="button" value="Clear" onclick="javascript:clearName()"><br>
<input type="text" id="demo1">
<input type="text" id="demo2">
<input type="test" id="userName">userName
</body></html>
在调用javaScript前要先引入刚才在dwr.xml中定义的javaScript
<script type='text/javascript' src='dwr/interface/MyTest.js'></script>
<script type='text/javascript' src='dwr/interface/showData.js'></script>
<script type='text/javascript' src='dwr/engine.js'></script>
<script type='text/javascript' src='dwr/util.js'></script>
前面两行是我们刚才定义的javaScript的引入，后面两行是dwr中的本身定义的javaScript
ok(完）
posted on 2006-06-27 10:17
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