Prerequisites for implementing Single Sign On in java based web application

Question

I have been trying to implement SSO in an existing java web-application. I have spent lot of hours to understand this thing but couldn't get success so far. Can anyone tell me some guided way by which I can achieve it.

I am looking for

1. With what module/API should I start
2. What will be best way to implement SSO for a beginner
3. Any good books/blogs/websites.

PS : I know Servlet/JSP and have built very simple application using JSP/Servlet till now. (NO FRAMEWORK).

Answer 1

What exactly do you mean by single sign on, is your application distributed or single sign on on different applications?

You could write filters for authentication and authorisation; where you check for a valid session and if the user has logged in; depending on that dispatch the request to a resource or login page.

Another option is to use Java EE declarative security.