Hey,
sorry, I haven't noticed this thread, so I've already commented on the
according JIRA issue
(https://issues.apache.org/jira/browse/MYFACES-2485). Basically I've
already mentioned it there, but I think the reason why only the
"contextDestroyed"-callbacks are invoked is that Tomcat, by default,
serializes and preserves sessions once it shuts down.
However, I'm pretty much sure that implementing such a registry
introduces more issues than it resolves (assuming that you consider this
to be an issue at all - which I wouldn't do). As Jan-Kees has already
pointed out, you can't just invalidate sessions once a container shuts
down in a clustered environment. I think it would break the whole idea
of a clustered environment.
regards,
Bernhard
Jakob Korherr wrote on 01/13/2010 09:17 PM (GMT):
Hi,
MyFaces is already using all available Listeners
(HttpSessionAttributeListener, HttpSessionListener,
ServletContextListener, ServletContextAttributeListener,
ServletRequestListener, ServletRequestAttributeListener) to invoke
@PreDestroy on the Managed Beans and this happens via a pass-through
from StartupServletContextListener, so you don't have to configure two
listeners in web.xml (or tld).
The problem is, as you thought, that those listeners (e.g.
HttpSessionListener) are not invoked on a container shutdown/restart.
Only contextDestroyed from ServletContextListener is invoked (tested
today on Apache Tomcat 6).
I will not change anything of the existing behavior, I just want to make
sure that all still existing ManagedBeans get their @PreDestroy method
called in contextDestroyed. But I would not get a reference to them, if
I do not register them in a ManagedBeanRegistry.
Regards,
Jakob
2010/1/13 Jan-Kees van Andel <[email protected]
<mailto:[email protected]>>
Hey,
How about an HttpSessionListener? I'm not sure if
HttpSessionListener.contextDestroyed is invoked on shutdownthough.
Probably not...
I'm afraid the only option is custom bookkeeping, maybe using an
HttpSessionListener/ServletContextListener to publish events to the
Registry.
I see some issues with this approach:
1 Configuration becomes more difficult for the application developer,
because these two Listeners become required configuration.
2 Managing objects yourself may be tricky business. An option could be
to use WeakReference/WeakHashMap for this so you don't accidentally
keep your objects alive.
3 What to do with regards to session replication on a clustered
environment? I'm not sure this will become an issue, but it wouldn't
surprise me if it will.
Regards,
Jan-Kees
2010/1/13 Jakob Korherr <[email protected]
<mailto:[email protected]>>:
> Hi guys,
>
> To ensure the execution of the ManagedBean's @PreDestroy methods on a
> container shutdown/restart, I would like to introduce a
ManagedBeanRegistry,
> in which all active ManagedBeans from all scopes are referenced.
>
> The problem is the following: At the moment on a container
shutdown or
> restart, only contextDestroyed is invoked (tested in tomcat 6),
thus only
> the @PreDestroy methods of all ApplicationScoped ManagedBeans will be
> invoked, but not those of any existing ManagedBeans in session,
request,
> view (and maybe also custom) scope, because they can not be
referenced in
> contextDestroyed().
>
> Any opinions on that?
>
> Thanks in advance!
>
> Regards,
> Jakob
>
