使用DWR注解Annotation

最新推荐文章于 2015-12-30 15:32:00 发布

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#DWR #Servlet #JavaScript #JavaEE #XML #ViewUI

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本文介绍如何使用Annotation配置DWR，包括在web.xml中指定自动加载的Java类，并展示了一个简单的示例，说明如何创建可远程调用的方法及可转换的对象。

Struts 2，Spring，Hibernate 都可以使用Annotation来代替XML的配置，DWR也可以使用Annotation注解来代替XML的配置

要使用Annotation注解，就得在web.xml中配DWR核心Servlet的时候加一个参数（classes），此参数会自动加载那些Java类

先看web.xml文件的配置：

<?xml version="1.0" encoding="UTF-8"?>
<web-app version="2.5" xmlns="http://java.sun.com/xml/ns/javaee"
	xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
	xsi:schemaLocation="http://java.sun.com/xml/ns/javaee 
	http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd">

	<!-- 配置DWR的核心Servlet -->
	<servlet>
		<!-- 指定DWR核心Servlet的名字 -->
		<servlet-name>dwr-invoker</servlet-name>
		<!-- 指定DWR核心Servlet的实现类 -->
		<servlet-class>org.directwebremoting.servlet.DwrServlet</servlet-class>
		<!--  指定DWR核心Servlet处于调试状态 -->
		<init-param>
			<param-name>debug</param-name>
			<param-value>true</param-value>
		</init-param>
		<!-- 配置DWR自动加载哪些Java类 -->
		<init-param>
			<param-name>classes</param-name>
			<param-value>com.lbx.dwr.annotation.test.Test,com.lbx.dwr.annotation.model.Person</param-value>
		</init-param>
	</servlet>
	<!-- 指定核心Servlet的URL映射 -->
	<servlet-mapping>
		<servlet-name>dwr-invoker</servlet-name>
		<!-- 指定核心Servlet映射的URL -->
		<url-pattern>/dwr/*</url-pattern>
	</servlet-mapping>

	<welcome-file-list>
		<welcome-file>index.jsp</welcome-file>
	</welcome-file-list>
</web-app>

相关的Java处理类@RemoteProxy相当<create... >

package com.lbx.dwr.annotation.test;

import org.directwebremoting.annotations.RemoteProxy;
import org.directwebremoting.create.NewCreator;

import com.lbx.dwr.annotation.model.Person;

@RemoteProxy(creator=NewCreator.class,name="Demo")
public class Test {
	
	//定义一个简单方法
	public String hello(Person person){
		return person.getName() + ",你好";
	}
	
}

@DataTransferObject转换相当 <convert... >@RemoteProperty
表明那些属性是可转换的

package com.lbx.dwr.annotation.model;

import org.directwebremoting.annotations.DataTransferObject;
import org.directwebremoting.annotations.RemoteProperty;

@DataTransferObject
public class Person {
	//使用Annotation标识下面两个属性是可转换的属性
	@RemoteProperty
	private String name;
	@RemoteProperty
	private int age;
	
	public Person() {
		
	}
	public String getName() {
		return name;
	}
	public void setName(String name) {
		this.name = name;
	}
	public int getAge() {
		return age;
	}
	public void setAge(int age) {
		this.age = age;
	}
	
}

客户端JSP代码

<%@ 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>DWR的Annotation支持</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/Demo.js'></script>
		<script type='text/javascript' src='dwr/engine.js'></script>
		<script type='text/javascript' src='dwr/util.js'></script>
		<script type="text/javascript">
			function sendMessage(){
				var p = {
							name:dwr.util.getValue("name"),
							age:"23"
						}
				Demo.hello(p,cb);
			}
			function cb(data){
				$("show").innerHTML = data;
			}
		</script>
	</head>

	<body>
		<h3>
			DWR的Annotation支持
		</h3>
		请输入您的名字
		<input id="name" name="name" type="text" />
		<br />
		<input type="button" value="发送请求" onclick="sendMessage();" />
		<hr />
		下面是服务器的回应:
		<br />
		<div id="show"></div>
	</body>
</html>