Session basics

• Session is an implementation of caching
• Session in Java never put in synchronized block as itself implemented thread safe
• While writing session, we need to be careful that updation of session data between multiple controllers since session data wll be same for all controllers.So application logic which was expecting some data has already modified by some other request.
• Also need to be careful to rewrite or reupdate session data for same controller between different request.
• One session per user but can put put many objects with in same session object