On May 27, 2008, at 3:50 PM, Andrew Thorburn wrote:
Yes, that helps a lot. It's not the answer I wanted, but it does
answer the question :).
I guess that means I'll have to play around and see what can be done.
How do separate classloaders work with statics (fields, etc). e.g.
If I have a class A with static field B in the WAR, and again in the
EJB jar, will I have two instances of that field, such that the WAR
has one (because it has it's own separate classloader), and the EJB
will have another? If so, then that's a problem.
With normal parent-first classloader delegation, only one copy of the
class will be loaded, the one in the ejb jar. If you turn on inverse-
classloading in the war, then you will get two copies: one in the ejb
jar visible to the ejbs, and one in the war, visible to the web app.
IMO it is almost never appropriate to turn on inverse-classloading. I
didn't discuss this detail in my first reply.
I don't know much about Java Beans or Enterprise Java Beans, so this
might be a bit silly, but: Can I put the MDB in the WAR? Or does it
*have to* have it's own JAR?
An mdb has to be in an ejb jar. (or a jar accessible to the ejb apps
classloader, such as in a jar in an ear lib directory). Since the web
app/war has a separate classloader that is a child of the ear
classloader, there's no way you will be able to get the mdb visible to
an ejb app if it is in the war.
I guess I should mention that I think openejb standalone has a mode in
which you can do something like what you seem to want to do, but it is
not standard javaee. I don't know too much about it.
hope this helps
david jencks
On Tue, May 27, 2008 at 6:03 PM, David Jencks
<[EMAIL PROTECTED]> wrote:
On May 26, 2008, at 6:28 PM, Andrew Thorburn wrote:
Ok, it now works. Well, kinda.
I think I must have originally also had a lib directory directly
inside the EAR, as well as in the WAR, which was what was confusing
Geronimo. Removed that, and my bean didn't start. Removed the (small
but important) bits of code that relied on that, and everything
works. Except it doesn't do logging anymore for my MDB. Works fine
everywhere else.
Apologies for not having the faintest idea what my problem was, but
there we go. I now have a new problem, however: How do I reference
the stuff in the WAR from my MDB JAR? I'm sure I saw information on
this somewhere, but I closed it because I thought I had a different
problem :(. I can't duplicate the JARS, as I'm sure that'll cause a
vast multitude of problems. I really just want to be able to
reference them easily, so that I don't have to worry about this when
coding my application. In fact, it's going to be very necessary to
communicate between the WAR and the MDB for it to be of any use at
all (AJAX stuff communicating between browser and database via Java
app). Basically need the WAR to be processed first, and then have
the MDB JAR processed, so that I can then reference all the classes
in the WAR.
Is this possible? If not, what's the best alternative? Can I chuck
my MDB into the WAR? I'd be very surprised if I could do that. And I
don't know if that would solve any of my issues anyway...
The exact location of the classfiles doesn't matter, just so long as
it all works...
Feh. This is starting to do my head in. Won't be posting again for
nearly 24 hours (I only work part-time).
I'm not sure I've understood clearly what problem you are having.
Maybe if I explain the classloader structure your app has and what I
think you need to do it will help.
For an ear based application with no javaee app clients, there is
one "base" classloader that includes all the ejb jars, all the rars,
and all the jars in the lib directory.
Then for each war inside the ear, there is a separate classloader
that is a child of the ear classloader that contains the jars in WEB-
INF/lib and the classes in WEB-INF/classes. Since this is a child
of the ear classloader, all the code in the war can see the classes
in the ear (ejb, connector, and lib). Also, since these war
classloaders are children of the ear, nothing in an ejb, connector
or lib jar can see anything in any war classloader.
I think what you need to do is put any classes that need to be
accessible to both the ejb app (such as your mdb) and the war(s) in
either the ejb jar or in a jar in the ear's lib directory. Putting
any such class anywhere in any war file will definitely prevent it
being accessible from the ejb application.
Hope this relates to what you are asking about :-)
david jencks
Anyway, thanks again,
- Andrew
