HTTP is a Statless protocol. Maintaining state is kludgy. This protocol was designed to do two things, Process a request (ie get a page) and close the connection. So How does one monitor state in an application? Good question.

There are three standard ways... Luckily Java Servlets provide the HTTPSession API. HTTPSession uses a combonation of cookies and url rewritting to accomplish this task. AND a lot of it is transparent to the user.

• Cookies - Store Session id in a cookie and send it back and forth to the user
• URL Rewriting - append parameters (session id) to the url
• Hidden Form Fields - Like this <input type ="HIDDEN" name="SESSION" Value = "123456" />

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Tutorial on HTTPSessions and HTTPSessionListener

Tutorial on HTTPSession Management.