本文主要是介绍dwr入门之HelloWorld，希望对大家解决编程问题提供一定的参考价值，需要的开发者们随着小编来一起学习吧！
首先到官网http://getahead.ltd.uk/dwr/ 上下载dwr.jar.
一个jar包dwr.jar放到WEB-INF/lib下,一个js文件 HelloWorld1.js,一个index.jsp,一个javabean HelloWorld.java
javabean代码
package com.dongaoacc.ajaxtest;
public class HelloWorld ... {
public String sayHelloWorldTo(String name) ...{
return "Hello World " + name + "!";
}
}
js代码,放到webroot下
function helloworld() ... { var user = $("user").value; alert(user); HelloWorld.sayHelloWorldTo(user, callback);} function callback(msg) ... { DWRUtil.setValue("result", msg);} jsp代码:
<% ... @ page language="java" import="java.util.*" pageEncoding="utf-8" %> <! DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" > < html > < head > < title > 第一個DWR程式 </ title > < script type ='text/javascript' src ='dwr/interface/HelloWorld.js' ></ script > < script type ='text/javascript' src ='dwr/engine.js' ></ script > < script type ='text/javascript' src ='dwr/util.js' ></ script > < script type ='text/javascript' src ='HelloWorld.js' ></ script > </ head > < body > < input id ="user" type ="text" /> < input type ='button' value ='测试' onclick ='helloworld();' /> < div id ="result" ></ div > </ body > </ html > web.xml:
<? xml version="1.0" encoding="UTF-8" ?> < web-app version ="2.4" 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" > < display-name > ajaxDWR </ display-name > < 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 > < welcome-file-list > < welcome-file > index.jsp </ welcome-file > </ welcome-file-list > </ web-app > dwr.xml,与web.xml并列放置:
<? 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 > < create creator ="new" javascript ="HelloWorld" scope ="page" > < param name ="class" value ="com.dongaoacc.ajaxtest.HelloWorld" /> </ create > </ allow > </ dwr > 注意：因为dwr.xml有javascript="HelloWorld",所以在jsp中必须有 <script type='text/javascript' src='dwr/interface/HelloWorld.js'></script>，用来据javabean暴漏给客户端．
另个js解本中方法名不能和类名一样．原来把方法名和类名都为HelloWorld，出现不支持对象或方法错误．小心啊．
测试方法：
http://localhost:8080/项目名/dwr
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