Working with Cookies

Session 6 - Servlet | Cookie state management

Types of cookie

Type	Behaviour
Non-persistent	Valid for a single session only. Removed when the browser is closed. Max age is -1.
Persistent	Valid across sessions. Survives closing the browser and is removed only on logout/signout. Max age is a positive number of seconds.

Advantages

• Simplest technique of maintaining the state.
• Cookies are maintained at the client side.

Disadvantages

• Does not work if cookies are disabled in the browser.
• Only textual information can be set in a Cookie object.

How the demo works

Step	URL	What it shows
1	CreateCookieServlet	Creates the cookies and adds them to the response.
2	GetCookieServlet	Reads the cookies back from the request and prints name, value and max age.
3	DeleteCookieServlet	Expires the cookies with setMaxAge(0).

Steps 2 and 3 are POST-only, so reach them through the buttons on the pages rather than by clicking the links above - the form on the login page is the proper entry point.

Go to the login page