Hi Bryan,
Can you put the stateful session bean within a JavaBean with synchronized
methods so that all access to the stateful session bean is through the
JavaBean?
--Abraham
> -----Original Message-----
> From: Bryan Field-Elliot [mailto:[EMAIL PROTECTED]]
> Sent: Thursday, April 05, 2001 8:09 AM
> To: [EMAIL PROTECTED]
> Subject: Frames, concurrency, and EJB Stateful Session beans - a
> problem.
>
>
> I'm having a design problem with my system, which is not really Struts
> specific, but since there are a lot of EJB users here, I thought I'd
> throw it on this list for comments --
>
> My business logic is all implemented in a Stateful EJB Session bean. All
> Struts users get one instance of the session bean, whose reference is
> stored in the Servlet's Session scope.
>
> All of my Struts actions are simple; they take data from the user
> (usually in ActionForms), pass them to some method in the EJB Session
> bean, and store the results in beans for the JSP page to render.
>
> However, my design calls for a few places where there is a frameset, and
> in another place, where two browser windows open up showing two
> different views. The problem here, is that EJB requires that a Stateful
> Session bean have only one thread of execution within it (e.g. no
> concurrency). So, when two different Struts actions (or custom tags) try
> to invoke a method on the same EJB Session bean reference at the same
> time, one of them will fail with an exception thrown by the EJB
> container (in my case, jBoss).
>
> Can anyone recommend an easy, general-purpose solution to this problem?
> (Please don't say, "switch to stateless session beans"). I suppose I
> need to syncronize access to the EJB bean from the client (and, in this
> case, the client is Struts), but I'm not sure how to do this quickly and
> elegantly.
>
> Comments would be appreciated,
>
> Bryan
>
>
>
