How to avoid JSP page automatically generate session object? Why do you do this?

Jsp

By default, when a request is made to a JSP page, if the session is not established, the JSP page automatically creates a session object for the request, but the session is more resource-intensive, and if it is not necessary to maintain and use the session, You should not create a session, such as some of the website is just to promote the product, often do not need to use the session to save information, you can use the JSP page directive session= "false" to avoid the JSP page for each request automatically created session. The instance code is as follows:

<%@ page session= "false" >

How to avoid JSP page automatically generate session object? Why do you do this?