How can I get the attribute of another app of the JSP server's session

Question

in one server, use Tomcat 4.1, have two application at
.../webapps/app1
.../webapps/app2
when use login to application1, it'll set a attribute of session use following code:
session.setAttribute("identitycode", IdentityCode);
session.setMaxInactiveInterval(SessionTimeOut);
and the other jsp programs which at app1 directory will try to get the attribute of this session to identity whether the user had login and get the identity code.
I want to make user just login one time to use application1 and application2, but I didn't know how to get the attribute of session what seted at app1 in app2's programs.
can you tell me how I can do this?

Answer 1

If there are 2 different applications like app1 & app2, U need to use:
application.setAttribute() method.(not session.getAttribute).
u need to maintain one collection like hash table which will store the mappings of User & their IDs . U can then get the user details from app1 to app2