Partner application access to portal login info

Question

How can an SSO partner application (Java) tell whether or not a user has logged in to Portal?
I need to log activity in a public application servlet, so I'd like to log the user as PUBLIC if not logged in or as their actual userid.
I don't seem to have access to this info until the user has visited a secure part of the app.
Any pointers would be appreciated.
Thanks
Rob

Answer 1

DIY answer ...
The cludge I used to get round this was ...
Make a PL/SQL item which displays a Login or Logout link as appropriate, based on the current userid from portal.wwctx_api.get_user.
The login link goes to a secure portal page called FORCE_LOGIN, passing a URL parameter called nextPageURL which contains the URL of the next page to show after the login is complete. You can use portal.wwpro_api_parameters.get_value( '_pageid', 'a'); to help build the current page URL if you want to retun to the current page.
The FOIRCE_LOGIN page contains a PL/SQL item which builds an IFRAME whos src is a URL to my app servlet ForceLoginServlet, passing on the nextPageURL parameter. Use portal.wwpro_api_parameters.get_value( 'nextPageURL', 'a'); to help with that.
The ForceLoginServlet is a secure servlet (set up in web.xml) so that forces a silent authentication to my app. All the servlet does is display HTML to redirect back to the URL in nextPageURL.
Horrible! But it does the job.
Anyone who know a better way of doing this, please tell me.
Rob