JEE authentification process

i'm a Beginner in JEE programming and i'm trying to make my first web application. here is what i trying to found out: -i understood how to use HttpSession object to start a session after verifying username and pswd

• but after this process should i verify (make a test (if) ) in every protected page(jsp file that only authenticated user can access)?

-is there any easiest way to do, or i should test in every page that a session is up else i redirect the person the authentication page

thank you for help