RE: [Springframework-developer] FW: [springframework - Help] AOP interception of FactoryBean components?

[<jue...@we...>]

PropertyValuesProviderFactoryBean is already dissolved :-)

I think the simplest way to optionally apply BeanPostProcessors to =
FactoryBean-created objects is to place the burden on the FactoryBean =
implementation: It is the one that knows when the objects actually get =
created and need BeanPostProcessors invoked on them.

I've just introduced a "applyBeanPostProcessors(existingBean,name)" =
method to the BeanFactory interface, accompanying the recently added =
"autowireExistingBean(existingBean,autowireMode,dependencyCheck)" =
method. A FactoryBean can implement BeanFactoryAware and invoke =
applyBeanPostProcessors for a given object whenever it feels the need =
to.=20

If a FactoryBean wants to pass its bean definition name to =
BeanPostProcessors invoked on its created object, it can additionally =
implement BeanNameAware, using that name for applyBeanPostProcessors =
invocations.

The alternative would be to place the burden on the BeanFactory =
implementation, requiring special means to check that BeanPostProcessors =
are just invoked once for any Factory-Bean created object. And that =
would require a new XML bean definition attribute too, just applicable =
to FactoryBeans, or a new method in the FactoryBean interface.

As custom BeanPostProcessors are a rather rare requirement anyway, I =
guess the programmatic solution should be sufficient. There's nothing a =
BeanPostProcessor can do that you couldn't to with a custom FactoryBean =
implementation, or an additional FactoryBean that fronts your existing =
FactoryBean. Invoke the new applyBeanPostProcessors there if you need =
to.

Juergen


-----Original Message-----
From: spr...@li...
[mailto:spr...@li...]On Behalf
Of Rod Johnson
Sent: Wednesday, December 03, 2003 1:33 PM
To: spr...@li...
Subject: Re: [Springframework-developer] FW: [springframework - Help]
AOP interception of FactoryBean components?


>Of course, a defined ProxyFactoryBean with a custom FactoryBean as =
target
would proxy the created object, as expected. But as Daniel noted, an =
auto
proxy creator would currently get applied to the FactoryBean instead of =
the
created object.
>Should we leave it that way? Bean properties, lifecycle methods, and =
also
bean post processors like ApplicationContextAwareProcessor are in fact =
meant
to be applied on the FactoryBean itself. Could we add a clean option to
apply bean post processors to the created objects, if demanded?

I think we should leave it that way by default, and perhaps add an
alternative option to post process created objects.

>BTW, I think that our current PropertyValuesProviderFactoryBean
sub-interface is useless. All the bean factory does with the =
PropertyValues
from there is to apply them to the created object via a newly =
instantiated
BeanWrapper: A FactoryBean implementation could easily do that itself =
with a
one-liner, if actually required.

Good point. Get rid of it if you like.

Regards,
Rod




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