Well, in some of the App servers I use(Orion, OC4J, JBoss), an uncaught
exception rolls back the current transaction. If you exectute
beanHome.findByPrimaryKey(...) and nothing is found, a FinderException
or a ObjectNotFoundException are thrown. Same goes for create() and
remove() methods. This may or may not work in some app servers. I think
it'll work in most, since the app server usually catches the Exception
and rethrows it, and the transactional context is set BEFORE method
execution. But it COULD be a problem, esp. if you're trying to cache
EJBHomes remotely(from a non-transactional client, for instance). Since
David was asking for potential problems and I'm not aware of the context
he'll have this working in, I mentioned the _potential_ risk. But I
think the risk is truly small.
I would go for the Singleton and cache the ejbHome instances barebones,
and fix it later if I find it not to be working, since all you'll be
needing is minor changes on the Singleton implementation, not the
interface:
public MyBeanHome getMyBeanHome() {
return (MyBeanHome) myHomes.getElement(MYBEAN);
}
Would then become:
public MyBeanHome getMyBeanHome() {
HomeHandle handle = myHomes.getElement(MYBEAN);
return (MyBeanHome) handle.getEJBHome();
}
No need to issue a "build all-classes-since-world-was-created" command.
HTH,
Juan Pablo Lorandi
Chief Software Architect
Code Foundry Ltd.
[EMAIL PROTECTED]
Barberstown, Straffan, Co. Kildare, Ireland.
Tel: +353-1-6012050 Fax: +353-1-6012051
Mobile: +353-86-2157900
www.codefoundry.com
> -----Original Message-----
> From: Sven E. van �t Veer [mailto:[EMAIL PROTECTED]]
> Sent: Tuesday, July 30, 2002 6:01 PM
> To: Juan Pablo Lorandi
> Subject: RE: Effect of "static" EJBHomeFactory vs. "singleton"
>
>
> So, for what I understand is that, in case you want to
> develop a 'portable' application that runs on *any* app
> server you should use a singleton that does not cache
> ejbHomes but maybe only the JNDI context or ejbHome handles ??
>
> But how about homes for session beans ? do they vote in
> transactions too ??
>
> >
> > Also bear in mind that such EJBHome cache may not work
> seamlessly in
> > all containers, since many may enroll the EJBHome instance in a
> > particular transaction, which will in turn make the
> instance useless
> > in any other transaction. An EJBHome is a fully blown transactional
> > component that executes business rules(altough they may not
> be coded
> > in Java but in SQL or EQL), and it may attempt to vote within the
> > current transaction to no avail. Storing handles to EJBHome
> instances
> > may work better, but with performance losses.
> >
>
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