JavaWEB开发中用到DWR时的配置、调用、Form提交的方法

DWR官方网站：

http://getahead.ltd.uk/dwr/

（一）添加DWRjar包：

从官网上下载jar包，放到lib目录下

（二）编辑配置文件

1.编辑配置文件web.xml:

以下几行代码必须被添加到WEN-INF/web.xml文件中。注意，要把<servlet>和其他<servlet>放在一起，<servlet-mapping>要和其他<servlet-mapping>放在一起

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

2.在web.xml目录下创建dwr.xml文件，内容如： 具体dwr配置详解可以下载：《dwr配置详解》

<?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> <!-- 指定绑定的formBean类的路径 --> <convert converter="bean" match="dwr.FormBean"/> <!-- javascript="service" 表示建立的js的方法名 --> <create creator="new" javascript="service"> <!-- 指定类文件的路径 --> <param name="class" value="dwr.Dwr" /> <include method="getFormBean"/> </create> </allow> </dwr>

其中formBean也可用Struts的生成的form，配置文件中写好路径、在类文件中的返回类型修改好，代码如：

<allow> <!-- 指定绑定的formBean类的路径 --> <convert converter="bean" match="thread.form.UserForm"/> <!-- 注意这里如不定义，会在控制台报警示错误，但不影响运行 --> <convert converter="null" match="org.apache.struts.action.ActionServletWrapper"/> <!-- javascript="service" 表示建立的js的方法名 --> <create creator="new" javascript="service"> <!-- 指定类文件的路径 --> <param name="class" value="dwr.Dwr" /> <include method="getFormBean"/> </create> </allow>

类文件修改：

public UserForm getFormBean(Map formMap){ ... UserForm userFomr = new UserForm(); try{ BeanUtils.populate(userFomr, formMap); .... return userFomr; }

（三）编写类方法：

在src的包中建立类文件，如：

package dwr; import java.util.Map; import org.apache.commons.beanutils.BeanUtils; public class Dwr { public boolean checkName(String name) { boolean flag = false; if("wq".equals(name)){ flag = true; } return flag; } public FormBean getFormBean(Map formMap){ try { synchronized (this) { this.wait(5000); this.notify(); } } catch (InterruptedException e1) { // TODO Auto-generated catch block e1.printStackTrace(); } FormBean formBean = new FormBean(); try{ BeanUtils.populate(formBean, formMap); }catch(Exception e){ e.printStackTrace(); } System.out.println("==============客户端传来的信息=============="); System.out.println("FormBean.username:"+formBean.getName()); System.out.println("FormBean.password:"+formBean.getAge()); System.out.println("========================================="); System.out.println("==============客户端传来的信息Map=============="); System.out.println("FormBean.username:"+formMap.get("name")); System.out.println("FormBean.password:"+formBean.getAge()); System.out.println("========================================="); return formBean; } }

代码：

synchronized (this) {
this.wait(5000);
this.notify();
}
使线程等待5秒，模仿网络延迟效果

formBean类文件：

package dwr; public class FormBean { private String name=""; private int age = 0; public int getAge() { return age; } public void setAge(int age) { this.age = age; } public String getName() { return name; } public void setName(String name) { this.name = name; } }

（四）运行项目，检测方法

运行项目后访问：http://localhost:端口/项目名/dwr，之后会出现之前定义的service的链接，点击进入后可以看到类中定义的方法如：

Methods For: service (dwr.Dwr) To use this class in your javascript you will need the following script includes: <script type='text/javascript' src="/test/dwr/interface/service.js" src="test/dwr/interface/service.js"></script> <script type='text/javascript' src="/test/dwr/engine.js" src="test/dwr/engine.js"></script> In addition there is an optional utility script: <script type='text/javascript' src="/test/dwr/util.js" src="test/dwr/util.js"></script> Replies from DWR are shown with a yellow background if they are simple or in an alert box otherwise. The inputs are evaluated as Javascript so strings must be quoted before execution. getFormBean( ); checkName( ); (Warning: checkName() is excluded: Method access is denied by rules in dwr.xml. See below)

（五）在页面中加入AJAX：

1.在页面中引入js文件路径：

<script type='text/javascript' src="/test/dwr/interface/service.js" src="test/dwr/interface/service.js"></script> <script type='text/javascript' src="/test/dwr/engine.js" src="test/dwr/engine.js"></script> <script type='text/javascript' src="/test/dwr/util.js" src="test/dwr/util.js"></script>

2.如果是验证单个的数据，如用户名：

function firstDwr() { service.checkName($("文本框名"), callBackHello); } //回调函数 function callBackHello(data) { alert(data); }

回调函数callBackHello(data)，data自动传入类方法的返回值进行操作

3.如果是提交表单操作：

<%@ 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></title> <script type='text/javascript' src="/test/dwr/interface/service.js" src="test/dwr/interface/service.js"></script> <script type='text/javascript' src="/test/dwr/engine.js" mce_src="test/dwr/engine.js"></script> <script type='text/javascript' src="/test/dwr/util.js" src="test/dwr/util.js"></script> </head> <mce:script type="text/javascript"><!-- function formsubmit() { dwr.util.useLoadingMessage("正在提交..."); var formMap = dwr.util.getValues("chackForm"); service.getFormBean(formMap, result); } function result(data) { alert("从服务端返回的数据：/nuserName:" + data.name + "/npassWord:" + data.age); } // --></mce:script> <body> <form name="chackForm" method="post"> <input name="name" type="text"> <input name="age" type="text"> <input id="sub" type="button" value="提 交" onclick="formsubmit()"> </form> <br /> </body> </html>