I don't have a complete answer. But part of it makes sense. Instead of a web application think of a
java swing application as the client for the ejb. You could look up a stateful session bean reference and then have some multithreaded functionality where each
thread invokes some method on the bean. This would mean concurrently calling two methods on the same bean instance and according to the spec will end up in an exception. However this only explains two calls coming from the same client. From your quote of the spec '..from the same or different client..', looks like it is implying that two different clients can invoke methods at the same time on the same bean instance. I do not think this is possible.
Ramakrishnan, could you claify how the second client would get access to the bean? Were you thinking of the first client passing it's reference to the second client? In that case, from the ejb's view wouldn't the two clients appear as just one client, since the second client would simply be using the first clients identify?
[ September 05, 2006: Message edited by: Arun Natrajan ]