Listening to when the user session is ended in a JSF managed bean

Question

Is it possible to do something like this: When a user session starts I read a certain integral attribute from the database. As the user performs certain activities in this session, I update that variable(stored in session) & when the session ends, then I finally store that value to the DB.

My question is how do I identify using the JSF framework if the user session has ended & I should then store the value back to DB?

Answer 1

Apart from the HttpSessionListener, you can use a session scoped managed bean for this. You use @PostConstruct (or just the bean's constructor) and @PreDestroy annotations to hook on session creation and destroy

@ManagedBean
@SessionScoped
public class SessionManager {

    @PostConstruct
    public void sessionInitialized() {
        // ...
    }

    @PreDestroy
    public void sessionDestroyed() {
        // ...
    }

}

The only requirement is that this bean is referenced in a JSF page or as @ManagedProperty of any request scoped bean. Otherwise it won't get created. But in your case this should be no problem as you're apparently already using a session scoped managed bean, just adding a @PreDestroy method ought to be sufficient.

Answer 2

My question is how do I identify using the JSF framework if the user session has ended & I should then store the value back to DB?

The JSF framework does not have a separate concept of a session; it uses the underlying session management features of the Servlet specification.

You would have to create a HttpSessionListener that provides hooks for you to capture the session creation and destruction events, where you can read the value and store it back into the DB.