When I write a bean, I'll most likely have my bean implement all of
the interfaces, so I would prefer to get an all-in-one-proxy. I can
see a case where I decide to add an interface after a library has
shipped, so I think the "doesn't have to implement rule" is a good
get out of jail free card :)
So how about a compromise....
proxy = looked-up-interface + all-implemented-interfaces
This way if you implement your interfaces, you get the cool all-in-
one proxy and you still can use unimplemented interfaces.
-dain
On Apr 12, 2007, at 12:19 AM, David Blevins wrote:
The title implies a much wider subject, so feel free to pipe in
with any requests that may be not be related to the bulk of this
email.
Anyways, there's an interesting facet to EJB 3 business interfaces,
namely that you can have as many of them as you want. One that
note, you can also implement your business interfaces in your bean
class whereas you could not with the old-style EJB 2.1 interfaces.
But as before, you do not have to implement your business
interfaces in your bean class, you can simply have "matching
methods" in the old ejb style.
So now here comes the question on what you as a user would like to
see us do (followed by the tricky part which is why we're asking).
What would you personally want, one proxy that implements all your
business interfaces or one proxy per business interface? The spec
requires us to support the one-proxy-per-interface approach, but
the all-interfaces-in-one-proxy approach could be supported... sort
of....
The trick is that if you do *not* implement your multiple business
interfaces and we try to create an all-in-one proxy, you could run
into a couple different issues and one of them is really really
nasty. Here they are, the first one is the worst IMHO as I just
ran into it and it's no fun :)
http://cwiki.apache.org/OPENEJB/multiple-business-interface-
hazzards.html
The important thing to remember is that these issues could only
happen if your bean does *not* implement it's business interfaces.
If it *does* implement it's business interfaces all these issues
would be sorted out at compile time and you'd never run into them
in the ejb container.
So, ... what would you want to see us do? Should we support both
or just the spec required approach? If we were to support it, what
would you like to see us do in the event that we encounter a bean
that cannot be supported via the all-in-one proxy approach -- would
a log message be fine or would you want to see us fail the deployment?
Thoughts?
-David
