Two dependent EJBs

[jon_evans]

Hi,

I'm fairly new to EJB. I'm using the latest stable JBoss, so that's EJB 1.1 spec. I'm posting this question here as I'm fairly certain its a generic EJB question, not JBoss specific.

I've defined a CustomerEJB (firstname, surname etc). and an AddressEJB (street, town, postcode etc.). I did it like that because potentially lots of objects in my app will need addresses, for instance CustomerEJB may end up with invoiceAddress and deliveryAddress.

My CustomerEJB has a getAddress method which does a lookup and returns an AddressRemote.

When I try to deploy CustomerEJB, I get an exception because AddressRemote cannot be found by the classloader, even though AddressEJB has deployed OK.

What is the best strategy here? Add AddressRemote.class to CustomerEJB.jar? What if I make some additions to the AddressRemote interface in the future, I don't want to have to deploy a new CustomerEJB. Should I just let the Customer class expose the Integer addressID and let the caller resolve it to an AddressEJB?

Your thoughts are appreciated...

Thanks,

Jon.

[pazu]

Perhaps you should add both beans .jar files to a single .ear file. JBoss puts all jar files contained it the ear in the classpath for the application.

[nhebert]

Jon,

As you describe your EJB deployment as being two
jar files, it is important to view deployed
jar, war, and ear files as *separate* deployment
units. As such they would have no class loader
visibility across the deployment units.

If there are any dependencies, you must include
the Home and Remote interfaces of the dependent
component. That way you have visibility even
if the dependent component is deployed in another
app server.

It is an easy trap to view a JBoss app server
install as an island. It might not be. It may be
part of a federation of app servers running on
different machines. In this very possible scenario
class loader visibility across deployment units
on seperate machines is impossible.

As Marcus, pointed out, if you have close coupling
where two components always occur together, then it
makes sense to deploy them togther in the same
DU.

Just my thoughts.

Cheers,

Noel.

[benwilcock]

Have a look at the answer I gave to Rich at theis address. It may be just what you are looking for.

http://www.jboss.org/modules/bb/index.html?module=bb&op=viewtopic&t=forums/ luck,

Ben