1、新建Liferay Projext， Plugin Type选择Porlet，Project Name输入：DWRTest

2、下载DWR的jar包，http://directwebremoting.org/dwr/downloads/index.html

3、将dwr.jar放置到Lib文件夹下

4、配置web.xml

 	<servlet>
		<servlet-name>DwrServlet</servlet-name>
		<servlet-class>uk.ltd.getahead.dwr.DWRServlet</servlet-class>
		<load-on-startup>12</load-on-startup>
	</servlet>
	<servlet-mapping>
		<servlet-name>DwrServlet</servlet-name>
		<url-pattern>/dwr/*</url-pattern>
	</servlet-mapping>

5、新建dwr.xml

        <?xml version="1.0" encoding="UTF-8"?>
	<dwr>
		<allow>
			<create creator="new" javascript="DWRTestService">
				<param name="class" value="com.example.DwrTest.DwrMain"/>
				<include method="echo" />
				<include method="getThisPrivateDate" />
				<include method="getThisPrivateDate2" />
				<include method="getThisPrivateDate3" />
			</create>
	
			<convert match="com.example.DwrTest.DwrBean" converter="bean">
				<param name="include" value="id,name"></param>
			</convert>
		</allow>
	</dwr>

6、添加 java的package， package名： com.example.DwrTest

java类:DwrMain.java 普通测试用

DwrBean.java bean测试用

7，DwrMain.java的代码如下：

package com.example.DwrTest;

import javax.servlet.http.HttpSession;

import uk.ltd.getahead.dwr.WebContext;
import uk.ltd.getahead.dwr.WebContextFactory;

public class DwrMain {

	/**
	 * public static test
	 *
	 * @param message
	 * @return
	 * @throws Exception
	 */
	public static String echo(String message) throws Exception {
		WebContext webContext = WebContextFactory.get();
		HttpSession session = webContext.getSession();
		String msg = message + "  " + session.getId();
		return msg;
	}

	/**
	 * private test
	 * @return
	 */
	private String getThisPrivateDate() {
		return "getThisPrivateDate";
	}

	/**
	 * public test
	 * @param session
	 * @return
	 */
	public String getThisPrivateDate2(HttpSession session) {
		return "getThisPrivateDate2" + session.getId();
	}

	/**
	 * bean test
	 * @return
	 */
	public DwrBean getThisPrivateDate3() {

		DwrBean bean = new DwrBean();
		bean.setId("id1");
		bean.setName("name1");
		return bean;
	}
}

package com.example.DwrTest;

public class DwrBean {
	private String id;
	private String name;

	public String getId() {
		return id;
	}

	public void setId(String id) {
		this.id = id;
	}

	public String getName() {
		return name;
	}

	public void setName(String name) {
		this.name = name;
	}

}

<%@ taglib uri="http://java.sun.com/portlet_2_0" prefix="portlet"%>

<portlet:defineObjects />
DWR TEST
<script src='<%=renderResponse.encodeURL(renderRequest.getContextPath() + "/dwr/engine.js")%>' ></script>
<script src='<%=renderResponse.encodeURL(renderRequest.getContextPath() + "/dwr/util.js")%>'></script>
<script src='<%=renderResponse.encodeURL(renderRequest.getContextPath() + "/dwr/interface/DWRTestService.js")%>'></script>

<script type="text/javascript">
	DWRTestService.echo("qwer",function(dataFromService) {
		alert(dataFromService);
	});

	DWRTestService.getThisPrivateDate2(function(dataFromService) {
		alert(dataFromService);
	});

	DWRTestService.getThisPrivateDate3(function(dataFromService) {
		alert(dataFromService.id + dataFromService.name);
	});
</script>

10、DWR的相关配置方法，请谷歌一下吧。

HttpServletRequest,HttpServletResponse,HttpSession 除了可以用WebContext webContext = WebContextFactory.get(); 还可以直接用参数来获取。