A stateful session bean manages complex processes or tasks that require the accumulation of data, such as adding items to a Web catalog’s shopping cart. Stateful session beans have the following characteristics:
They manage tasks that require more than one method call to complete, but are relatively short-lived. For example, a session bean might manage the process of making an airline reservation.
They typically store session state information in class instance data, and do not survive server crashes unless they are run in a cluster that has persistent storage enabled for the component.
There is an affinity between each instance and one client from the time the client creates the instance until it is destroyed by the client or by the server in response to an expired instance timeout limit.
For example, if you create a session bean on a Web server that tracks a user’s path through the site, the session bean is destroyed when the user leaves the site or idles beyond a specified time
