DWR学习笔记-Hello World篇

 刚好一个项目要用ajax, 使用的产品平台使用DWR,就顺便了解一下DWR。

1. 下载DWR,首先将DWR.JAR包加到工程中
2. 在web.xml添加下面代码

    <servlet>
        <description>Direct Web Remoter Servlet</description>
        <display-name>DWR Servlet</display-name>
        <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>activeReverseAjaxEnabled</param-name>
            <param-value>true</param-value>
        </init-param>
        <init-param>
            <param-name>
                initApplicationScopeCreatorsAtStartup
            </param-name>
            <param-value>true</param-value>
        </init-param>
        <init-param>
            <param-name>maxWaitAfterWrite</param-name>
            <param-value>500</param-value>
        </init-param>
        <init-param>
            <param-name>crossDomainSessionSecurity</param-name>
            <param-value>false</param-value>
        </init-param>
        <load-on-startup>1</load-on-startup>
    </servlet>
    <servlet-mapping>
        <servlet-name>dwr-invoker</servlet-name>
        <url-pattern>/dwr/**//*</url-pattern>
    </servlet-mapping>

 

3. 编写HelloWorld代码类

package helloworld;

public class HelloWorld...{
    public String sayHello(String username) ...{
        return "hello " + username;
    }
}

4. 创建dwr.xml文件（默认在WEB-INF目录下）

<?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="service">
          <param name="class" value="helloworld.HelloWorld"/>
    </create>
  </allow>

</dwr>

5. 启动WEB服务器，运行http://localhost:8080/dwrdemo/dwr可以测试看看