Insted of using portletSession, you can use HttpSession object to store such information, try this code snippet:

import javax.security.jacc.PolicyContext;
import javax.security.jacc.PolicyContextException;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpSession;

request = (HttpServletRequest) PolicyContext.getContext("javax.servlet.http.HttpServletRequest");
request = (HttpServletRequest) PolicyContext.getContext("javax.servlet.http.HttpServletRequest");

HttpSession httpSession = request.getSession();

Isn't there a way to share attributes between portlets not in a same Application ?

Isn't it possible to use the <shared-session-attribute> element in portlet.xml to share attributes through session between portlet not of a same application ?

I have tried to set this element to true or to the attribute name but i'm not able to see attributes from a portlet to another.

I have tried your code in JBoss portal 2.7.2 and i got an error :

java.lang.IllegalArgumentException: unknown handler key
     at javax.security.jacc.PolicyContext.getContext(PolicyContext.java:280)

Well JBoss 2.7.2 implements JSR 286 so i should be able to use the shared-session-attribute but it doesn't work better...

There is no such thing as "shared-session-attribute" in the JSR-286

Yeah you're right it's just an enhancement of JSR 286.

I thought it was in the final version of the JSR...

Sorry about that.

Can anyone suggest any solution/workaround for sharing data across different pages?