dan benanav wrote:
>
> Here is something that I wonder about. There are session beans as referred to below
>and
> there are also ejb session beans. Ejb session beans should only be accessed by one
> client at a time (which I assume means one thread). Often session beans call on ejb
> session beans. But since session beans might be call by more then one thread at a
>time
> you shouldn't do that.
>
> So how can ejb session beans be used from a session bean?
I haven't studied interfacing to EJB in detail (yet), but I assume you can
use "synchronized" around the block of code that calls the EJB. But I also have
a feeling that EJB already takes care of serializing calls to session EJBs,
so it may not be necessary. As far as I know, a "session" in EJB terms is the
same as for servlets (a series of requests from the same client), so conceptually
it shouldn't be a problem.
But as I said, I haven't looked at this enough yet. If I'm wrong, I hope someone
corrects me.
Hans
> Hans Bergsten wrote:
>
> > Jari Worsley wrote:
> > >
> > > Session scope beans are available to a user and their browser session (I'm 99%
>sure
> > > that one session corresponds to connection from one browser program).
> > > So if a user has two browser windows open accessing pages on your site, then they
> > > can potentially create simultaneous requests that access the same bean in session
> > > scope. So session beans need to be thread safe.
> >
> > Actually, one session corresponds to a set of requests from the same client within
>a
> > certain period of time (the connection between the client and server may be
> > closed and reopened, but the session remains).
> >
> > But yes, a user with multiple browser windows can cause multiple requests
> > within the same session. Other cases are when you use frames where the
> > content of each frame is from a JSP page; the browser will request all frames
> > at roughly the same time so you have multiple requests in the same session.
> > And another is a user that keeps hitting the Submit button before the response
> > is delivered; every time a new request is made but the previous request may
> > still be executing.
> >
> > Hans
--
Hans Bergsten [EMAIL PROTECTED]
Gefion Software http://www.gefionsoftware.com
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