> -----Original Message-----
> From: Jeremias Maerki [mailto:[EMAIL PROTECTED]
> Sent: 20 December 2001 15:32
> To: Avalon Developers List
> Subject: Re: Avalon and J2EE : Best practices
>
> Hi Vincent
>
> Today, I've taken your collected thoughts and put them to use. They
were
> very clear and helpful and I'm quite pleased with the results. Well, I
> haven't done any direct EJB testing, yet. I've expected pitfalls but
> there weren't any until now.
Thanks Jeremias. We have made progress with our application and have now
completely integrated Avalon and J2EE and it works fine.
Here are some ideas (I will try to find some time later in January to
participate in a chapter on J2EE integration in "Developing With Avalon"
and to package a sample application showing it in real) :
- With WL 6.1, it is not possible to specify that a war should be
deployed before an EJB jar. Thus we had to move the initialization of
Excalibur CM to an EJB that we package in a separate EJB jar. Then, it
is possible with WL 6.1 to explicitely define the deployment order of
EJB jar. We save the CM as a static variable or this initialization EJB.
- In order to consistently do logging (with Log4J) and configuration
(single system configuration file) in both J2EE component and Avalon
components, we have done the following :
* Created a Logger component,
* Created a Configuration component (that uses properties file - I will
submit it for Excalibur in beginning of January),
* Defined an AbstractComponent class that is Composable, retrieve the
Logger and Configuration components from the CM and offers 2 getters :
getLogger() and getConfiguration()
* Our Avalon components extends AbstractComponent
* We have a ComponentUtilities static class for other non EJB and non
Avalon classes (during the migration phase and before all non EJB
classes are components or attached to components) :
public final static ComponentManager getComponentManager()
{
// Get CM from static variable
return InitialisationEJB.manager;
}
public final static Component getComponent(String role)
{
final ComponentManager manager = getComponentManager();
Component component;
try
{
component = manager.lookup(role);
}
catch (ComponentException e)
{
throw new CriticalException("cannot get component for role [" +
role + "]", e);
}
return component;
}
* We have defined a AbstractEnterpriseBean class that extends
AbstractComponent. It contains empty EJB lifecycle methods that are
common to session beans and entity beans. In the default constructor, we
call :
compose(ComponentUtilities.getComponentManager());
* We also have a AbstractSessionBean and AbstractEntityBean classes that
extend AbstractEnterpriseBean and simply add the empty EJB lifecycle
methods related to Session beans and entity beans respectively.
* We have a EJBUtilities class with static methods to get EJB home and
bean reference (saved as static variables). We will probably move this
class to be a single threaded Avalon component in the future.
Thus we are able :
- to use Avalon Components
- to use standard java classes (to be migrated to components in the
future or will act as helper classes of components)
- to use EJBs
- All 3 kinds can call each other with no problem
- All 3 kind use a unified system configuration file
- All 3 kind use a unified logging service (based on Log4j)
> I think it would be very helpful if these
> ideas could be integrated into Berin's "Developing with Avalon" at
some
> time. I'd gladly help doing it as soon as I've finished those two
> projects I'm currently working on (that will be the beginning of
March,
> I think).
>
definitely. + a sample j2ee application that shows it all.
-Vincent
> On Sat, 10 Nov 2001 18:04:51 -0000 Vincent Massol wrote:
> > Hi,
> >
> > I have just finished reading the excellent "Developing with Avalon"
PDF
> > (thanks Berin !) and am very eager to introduce Avalon in my current
> project
> > : e-business project using J2EE 1.3.
> >
> > Here is how I view the integration. I'd like to have feedback in
order
> to
> > confirm this is the best way to use Avalon in J2EE :
>
> <snip/>
>
> > What do you think ? Am I missing something ? As someone already done
> this ?
>
> Cheers,
> Jeremias Märki
>
> mailto:[EMAIL PROTECTED]
>
> OUTLINE AG
> Postfach 3954 - Rhynauerstr. 15 - CH-6002 Luzern
> Fon +41 (41) 317 2020 - Fax +41 (41) 317 2029
> Internet http://www.outline.ch
>
>
> --
> To unsubscribe, e-mail: <mailto:avalon-dev-
> [EMAIL PROTECTED]>
> For additional commands, e-mail: <mailto:avalon-dev-
> [EMAIL PROTECTED]>
>
--
To unsubscribe, e-mail: <mailto:[EMAIL PROTECTED]>
For additional commands, e-mail: <mailto:[EMAIL PROTECTED]>
