PageRedirectException throws a NullPointerException in a Portlet

[Liu Yan <yl...@gmail.com>]

hi,

I am using JBoss Portlet 2.2 plus T4 based portlet. What I am trying to do
is to control the display of a Login form in a portlet. My idea is having a
Login page with username and password input fields, and an Empty page
displays nothing. In the Login's pageValidate() method, I will throw out a
PageRedirectException to redirect to the Empty page in case the user already
logged in.

However, I got the following exception, which I think probably this is not
the right approach:

 java.lang.NullPointerException
Property 'actionResponse' of <OuterProxy for
tapestry.portlet.PortletRequestGlobals(
org.apache.tapestry.portlet.PortletRequestGlobals)> is null.

Any ideas on this?

Regards,
Liu Yan