Home/ Questions/Q 6148649
In Process

The Archive Base Latest Questions

Editorial Team
  • 0
Asked: 2026-05-23T19:19:03+00:00

Suppose I let my customer reserve seats on a plane using Stateful Session Bean.

  • 0

Suppose I let my customer reserve seats on a plane using Stateful Session Bean. If the client explicitly calls my Remove method, all of his reservations will be cancelled and the bean is removed afterward.

However, in case the client is idle for some time and the Bean get passivated, if the Bean times out while being passivated, it would be deleted without calling any of my functions. Hence, I’d be very grateful if someone could show me how I can make sure that the reservations would be cancelled if the bean get deleted. If I use the @PreDestroy annotation, will it solve this problem?

Best regards,
James Tran

Share

Leave an answer

You must login to add an answer.

Need An Account,

1 Answer

  1. Editorial Team

    It is quite possible for the @PreDestroy method to not be invoked. The EJB 3.1 specification, explicitly states this:

    4.6.3 Missed PreDestroy Calls

    The Bean Provider cannot assume that the container will always invoke
    the PreDestroy lifecycle callback interceptor method(s) (or ejbRemove
    method) for a session bean instance. The following scenarios result in
    the PreDestroy lifecycle callback interceptor method(s) not being
    called for an instance:

    • A crash of the EJB container.

    • A system exception thrown from the instance’s method to the container.

    • A timeout of client inactivity while the instance is in the passive state. The timeout is specified by the Deployer in an EJB container implementation-specific way.

    The specification also details how resources may be removed if the @PreDestroy method is not invoked in such scenarios:

    For example, if a shopping cart component is implemented as a session
    bean, and the session bean stores the shopping cart content in a
    database, the application should provide a program that runs
    periodically and removes “abandoned” shopping carts from the database.

    In your case, it would depend on how you are storing the state of your reservations. If they are persisted in the database, then I would suggest employing the same approach as mandated in the specification. You could use the EJB Timer service, to perform this activity periodically, or use a scheduler like Quartz. Note, that it is imperative to distinguish between the contents of passivated session bean instances that no longer exist, and those that will be made ready once again.

    • 0