In our web application, we need to prevent multiple login of the same user. (e.g. User logs in as "user1" in a browser in machine one, does not log out, then later logs in as "user1" in a browser in another machine) In the example mentioned, the logged in session in the first machine should be invalidated. Spring can handle this. The issue is we have an existing application that does not make use of Spring and we wanted to implement the same thing. We need a quick fix for this and we do not have time to implement Spring in the app.