In a web-application implemented in java using JSP and Servlets; if I store information in the user session, this information is shared from all the tabs from the same brows
You have to realize that server-side sessions are an artificial add-on to HTTP. Since HTTP is stateless, the server needs to somehow recognize that a request belongs to a particular user it knows and has a session for. There are 2 ways to do this:
What are you trying to do anyway? Why would you want tabs to have separate sessions? Maybe there's a way to achieve your goal without using sessions at all?
Edit: For testing, other solutions can be found (such as running several browser instances on separate VMs). If one user needs to act in different roles at the same time, then the "role" concept should be handled in the app so that one login can have several roles. You'll have to decide whether this, using URL rewriting, or just living with the current situation is more acceptable, because it's simply not possible to handle browser tabs separately with cookie-based sessions.