On Aug 24, 2007, at 9:34 AM, Jonathan Gallimore wrote:
Thanks for the feedback. I'm still using EJB 2, and haven't used
EJB 3 before. My new EJB 3 book is on its way from Amazon.
Great. I like the O'Reilly one. Though I haven't really read the
book since Richard retired for book authoring.
It sounds like what I've done for generating a deployment
descriptor for EJB 2 is unlikely to be useful to people using EJB
3, and perhaps any kind of deployment descriptor generator is
unnecessary to those people?
Pretty much. A bit more detail below.
I'm sure I can convince people at work that we need to move to EJB
3, if that's what's recommended.
The great thing about ejb3 is that for quite a lot of it it's
subtractive, so you're not really moving but re-moving. Any app
becomes an EJB 3.0 app the second you delete the namespace in the ejb-
jar.xml that declares it is 2.1 (or 2.0, etc). It will be assumed as
an EJB 3.0 app and from there you can keep deleting. The more
annotations you add, the more descriptor you can delete. It's a
pretty direct conversion for Session beans and MessageDriven Beans.
Let me give you the crib notes:
@Stateless or @Stateful on a class replaces the descriptor tags
<session>, <ejb-name>, <session-type>Stateless</session-type>, and
<session-type>Stateful</session-type>.
@RemoteHome or @LocalHome is used on a class to replace <home> or
<local-home>. We inspect the actual home or local-home interface to
determine the related <remote> or <local> interface.
@TransactionManagement on a class replaces <transaction-type>
@TransactionAttribute on a class and/or method replaces <container-
transaction>. You'll need one @TransactionAttribute for each
<container-transaction>/<method> xml element. A <method-name>*</
method-name> would turn into an @TransactionAttribute on a class,
everything else would go on methods.
@EJB used on a class replaces <ejb-ref> and <ejb-local-ref>. @EJB
used on a field or setter method (private or public) request
injection of that EJB as well. When @EJB is used on a class the
"beanInterface" attribute is required. When used on a field or
setter method, the "beanInterface" attribute defaults to the type of
the field or setter method.
@Resource used on a class replaces <env-entry>, <resource-ref>,
<resource-env-ref>. @Resource used on a field or method (private or
public) requests injection of that resource. When @Resource is used
on a class, the "type" attribute is required. When used on a field
or method, the "type" attribute defaults to the type of the field or
setter method.
There are more annotations obviously, but these are fairly simple and
get rid of a ton of xml.
I'm still planning on doing more work the XDoclet plugin, just
hoping for some spare time when the day job isn't getting in the
way ;-)
If you're interested in working on a truly cool tool, help us write
the anti-XDoclet :)
http://www.nabble.com/ejb-jar.xml-to-Annotations-tool-tf4325175.html
-David
Jon
David Blevins wrote:
On Aug 24, 2007, at 7:57 AM, Ueberbach, Michael wrote:
Hello,
I followed the discussion about using XDoclet with great
interest. I have been using XDoclet for the last four years to
generate EJB applications and it has been very usefull all the
time. But meanwhile (since EJB 3) I think the situation has
changed dramatically. Most of what I have done with XDoclet
(creating local or remote interfaces, utility classes, homefinder
classes, value objects and so on) isn't neccessary anymore. There
is also no more need for generating any large deployment descriptor!
After converting my old EJB 2 projects to EJB 3 there remain only
two artefacts that still have to be build: A very little
persistence.xml and a deployment plan for geronimo. What is
important for the last one is, that there are no cmp entries to
be made inside the openejb-jar.xml because this can all be done
by annotations inside the bean code. The only important entries
made in the deployment plan are some dependencies to special
libs. So I wonder what XDoclet really can do in this case?
Probably it was the great success of XDoclet that lead to the
annotation concept of EJB 3 and in consequence made XDoclet less
usefull (only for this kind of code generation naturally).
I'm interested to hear other opinions on this item.
I think you captured the spirit of the new EJB 3.0 annotations
pretty well. In fact, internally we read in all the annotations
and use them to create or update your ejb-jar.xml (ala a nice jaxb
tree) in memory which we then use to deploy your app.
-David
regards
Michael
Von: Jonathan Gallimore [mailto:[EMAIL PROTECTED]
Gesendet: Dienstag, 21. August 2007 15:39
An: [email protected]
Betreff: Re: Using XDoclet to generate openejb-jar.xml
Hi Erik,
At the moment, I'm part way through getting our applications
working on Geronimo / Websphere-CE. We basically have two
applications - our core application which is used for building
publications, and another app that acts as a asset management
system, and integrates with our core app using JMS. The first one
of the two is now up and running on a Websphere-CE server, and
hasn't really taken much to get it working at all.
Largely all I needed the J2G tool to do was create some new
deployment descriptors, which it did without any real problems. I
needed to add some EJB refs to my geronimo-web.xml, and I needed
to create a jms-resource-plan.xml myself. At first glance it
didn't appear to generate much in the way of <message-driven>
elements and I was a fair way through creating a patch to
generate what I could from ejb-jar.xml and then I realised there
was some code to do it from annotations in the source. By far and
away the biggest problem I encountered was with how our EARs were
laid out. I think JBoss is too forgiving with its classloader -
we had a core.jar file inside our EJB.jar and nothing in any jar
manifests that specified any kind of classpath. (I believe it was
done in JBoss-IDE using this: http://docs.jboss.com/jbosside/
tutorial/build/en/pdf/JBossIDE-Tutorial.pdf as a guide). I needed
to do quite a bit of work to get it repackaged so that Websphere
would be happy with it.
I now need to do the same thing with the other app - I think this
will be more involved, we've used more JBoss specific classes in
places, so it'll hopefully be a good test of the J2G tool in
terms of its code conversion abilities. I'll let you know how I
get on.
Overall I thought J2G was great (although it took ages to get it
to build - it wasn't obvious that Maven was going nuts because I
was using JDK1.6 - I couldn't find a binary on the web - is it
worth adding a link from the cwiki pages?) The reason behind
exploring the XDoclet route, is rather than 'migrating' to
Geronimo, we'd like to add it to the app servers we can support.
Going forward, we'd like new beans we add etc to work on both
without needing to run J2G again, or editing two sets of files.
But in terms of getting the apps going ont Geronimo in the first
place, J2G has made the task much easier.
I'd be more than happy to contribute to the J2G project if I can.
Hope that's helpful.
Regards
Jon
Erik B. Craig wrote:
Jon,
I am one of the developers that contributed to j2g most
recently, and I am wondering if you had any specific comments on
it, or thoughts on any areas that you thought could use some
improvement? I've been hoping someone would, like yourself, use
it in a real world scenario to really give it a solid test, as
the best I've been able to do are 'mock' situations in testing.
Any input you could give would be great, especially if it would
be something you might be interested in helping out with a bit,
as well. Oh, and another quick thing, did the version you played
with incorporate eclipse ui plugins and annotations support yet,
or no?
Thanks!
--
Erik B. Craig
On 8/14/07, Jonathan Gallimore <[EMAIL PROTECTED]> wrote:
Hi All,
Apologies if this has been asked before, but I was wondering
whether anyone uses XDoclet to generate their openejb-jar.xml
deployment descriptors?
Currently we're developing for JBoss 4, and are part way through
getting our app to deploy on the community edition of Websphere.
The J2G migration tool has done an excellent job of migrating
our deployment descriptors, but going forward I'd still like to
add all the necessary XML stuff for new EJBs using XDoclet
rather than hand editing the openejb-jar.xml. Having hunted
around it looks like the openejb task that comes with XDoclet is
for a much older version, and only handles session beans.
I've started work on an xdoclet plugin that generates a basic
openejb-jar.xml for me, and I was just wondering whether I had
missed an existing tool/plugin and was just duplicating work
(obviously if I haven't and this is a useful piece of work, I'd
be happy to continue and share it).
I'd appreciate any thoughts anyone has.
Regards,
Jon
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