I tried the response.getCacheControl().setUseCachedContent(true). but it does not work.

Here is my portlet class

-

package com.mycompany.frs.portlet;

public class CacheDemo extends GenericPortlet

{ 

public void doView(RenderRequest request, RenderResponse response) throws PortletException, IOException

{

System.out.println("**---- " + this.getClass().getName() + "'s doView is started");

if (request.getETag() != null)

{

if (request.getETag().startsWith("MY_ETAG"))

{

System.out.println("/////// MARKUP IS VALID");

response.getCacheControl().setExpirationTime(30);

response.getCacheControl().setUseCachedContent(true);

return;

}

}

else

{

response.getCacheControl().setETag("MY_ETAG" + (new Date()));

response.getCacheControl().setExpirationTime(30);

PortletRequestDispatcher dispatcher = getPortletContext().getRequestDispatcher("/WEB-INF/CacheDemo.jsp");

dispatcher.include(request, response);

}

} 

}

portlet.xml =

<portlet>

        <description>CacheDemo</description>

        <portlet-name>CacheDemo</portlet-name>

         <display-name>CacheDemo</display-name>

         <portlet-class>com.mycompany.frs.portlet.CacheDemo</portlet-class>      

         <supports>

             <mime-type>text/html</mime-type>

             <portlet-mode>VIEW</portlet-mode>

         </supports>

         <supports>

             <mime-type>text/html</mime-type>

             <portlet-mode>EDIT</portlet-mode>

         </supports>

         <supports>

             <mime-type>text/html</mime-type>

             <portlet-mode>HELP</portlet-mode>

         </supports>

         <portlet-info>

             <title>CacheDemo</title>

             <short-title>CacheDemo</short-title>

         </portlet-info>

         <expiration-cache>30</expiration-cache>          

     </portlet>

CacheDemo.jsp

<%@page import="java.util.Date"%>

<H1> Hello Friends, I am cached contents !! </H1>

<%= new Date() %>

Platform : Jboss Portal 2.7.2

Problem :

When I refresh the page after 30 seconds, the portlet vanishes from the Portal page.

When I again refresh the page immediately, the portlet appears, with the cached contents. That is, it does not show the current date

-----------------

Thanks

Umesh Pathak