JSP nine large built-in objects of the session and application

The session and application are used especially for application, but want to learn a lot about the built-in objects.

The session is also referred to as the period during which the user enters the browser to close the browser. Session in front and back can be used, each time the user opens the browser to create a session, and then can be in front of the background to get the session object but cannot be created, get the way there are many foreground because it is built-in objects so you can directly use this object, In the background can be obtained through the request of the object, of course, there are other ways.

The purpose of session is to store login objects so that each foreground page can be used to determine whether the user is logged in, not landing on the return. There is a shopping cart, but now most of the shopping cart is implemented with database tables so that things in the shopping cart can be stored for a long time.

Application and session have many similarities, but application is when the server starts to create objects until the server shuts down, the purpose is to count the number of people online

JSP nine large built-in objects of the session and application