Questions on the @ServiceClient annotation and Asynchronous webservices

Question

1. Is their a way to invoke a webservice in an asynchronous manner without using the @ServiceClient annotation? I’ve tried a few things to get access to the async versions of the web methods and each time I get an exception stating “java.rmi.RemoteException: Asynchronous methods can only be invoked from stubs with the ServiceClient annotation”.
2. Is their anyway to generate a dynamically sized array of service port variables with the @ServiceClient annotation? All the examples that I have seen only have a single port variable annotated with @ServiceClient. I’ve tried creating a class that uses the @ServiceClient annotation, and while it does compile it fails when I try to invoke the services methods. I also found in some documentation a restriction that the @ServiceClient annotation can only be used in the core java (jws) webservice class.
3. Is their a way to use a single service port variable with the @SeriviceClient annotation to invoke multiple calls to an asynchronous web method if that web method is part of a conversation? When I tried this I found that even though the asynchrounous calls were going out with any problems they were being processed serially on the target services side (I assume due to the conversation).
The problem I am trying to solve is I need to invoke a stateful webservice in an asynchronous manner multiple times from the same starting service.

Answer 1

Hi
That is how I understand that document:
Locking: Forms, by default, locks a row as soon as the user starts modifying the data. That is pessimistic locking. Apex, on other hand (and optionally forms also) do not lock the record, but before applying any changes checks if the data has changed since the user queried it (what for some reason is called optimistic "locking")
DB connections: I am not sure why they used the terms synchronous/asynchronous, but the difference is that Forms, by default, keeps an permanent DB connection while the user is using the application, while Apex gets a connection from a connection pool every time a page is requested/submitted.
Architecture: Forms (in its web version at least) has 3 tiers: the browser, the appserver where the forms service runs and the database. As Apex runs inside the database, there are only 2 tiers: the browser and the database (though you still may need an http server in between which serves static content, I don't think it is considered part of the application in this context). If you are talking about client/server forms, then there are only 2 tiers.
I hope this helps!
Luis