Re: [Springframework-developer] Re: Re: Intercepting a Prototype Bean

SourceForge Headquarters 1320 Columbia Street Suite 310 San Diego, CA 92101 +1 (858) 422-6466

I think I can change it in M3. However, they will be equals() and have the
same target.

Regards,
Rod

>
> <bean id="proto"
>     class="org.springframework.aop.framework.ProxyFactoryBean">
>     <property name="singleton"><value>false</value></property>
> </bean>
>
> a call to
>
>     beanFactory.isSingleton("proto");
>
> will return true, but repeated calls to
>
>     beaFactory.getBean("proto")
>
> will indeed return separate prototype instances.
>
> Personally, I find this very counterintuitive and would be happy to see
this
> changed ;)
>
> Roger
>
>
>
> "jürgen höller [werk3AT]" <jue...@we...> wrote in message
> news:170...@co......
> Roger,
>
> This is indeed true, and I have not been aware of it: If a FactoryBean is
> defined as prototype, getBean will currently return the FactoryBean
itself.
>
> There are obviously two solutions for this:
> 1. make getBean return the FactoryBean-created object even for FactoryBean
> prototypes
> 2. require FactoryBeans to be defined as singletons by forbidding
> singleton="false"
>
> Option 2 isn't bad in the first place, as it's hard to image why a
> FactoryBean itself should be a prototype. Of course, option 1 could be
> easily implemented too, and it leaves the choice to the application
> developer. Opinions?
>
> We should definitely address this for 1.0 M3, to be released this weekend!
>
> Juergen
>
>
> -----Original Message-----
> From: spr...@li...
> [mailto:spr...@li...]On Behalf
> Of roger holbrook
> Sent: Thursday, November 20, 2003 7:28 PM
> To: spr...@li...
> Subject: [Springframework-developer] Re: Intercepting a Prototype Bean
>
>
> Rod
>
> I think this is a probably bug in AbstractBeanFactory - currently any
> getBean() for a FactoryBean that was defined with a bean attribute of
> singleton="false", will always return the FactoryBean instance, rather
than
> a Proxy instance.  This happens because createBean() does not do any
factory
> dereferencing.
>
> One fix would just be to trap the combination when the beans are being
> defined.
>
> Even if createBean() were actually handling the dereferencing correctly,
> I think there would still be a problem on a normal sequence of getBean()
> calls - since each call would generate a new FactoryBean instance and a
new
> Proxy instance, but the application code would only ever see a reference
to
> the latter.  Application code would only be able collect references to the
> FactoryBean themselves by explicitly calling getBean("&name"), and then
> using these to generate Proxy instances.
>
> A bit confusing really
>
> Roger
>
>
> "Rod Johnson" <rod...@in...> wrote in message
> news:06aa01c3af8b$d4467c90$e900a8c0@chopin...
> > Mark,
> >
> > > Is it possible to apply an interceptor to a prototype bean?
> > Yes.
> >
> > > The prototype is stateful - i.e one per user
> > Yes, Spring supports mixins, ie one interceptor per mixin instance.
> >
> > > I have defined the following in applicationContext.xml
> > >
> > >
> > > <bean id="TestTarget" class="test.MyTarget" singleton="false">
> > > </bean>
> > >
> > >
> > > <bean id="TestInterceptor"
> > >
> >
>
class="org.springframework.transaction.interceptor.TransactionProxyFactoryBe
> > > an" singleton="false">
> > > <property name="transactionManager"><ref
> > > local="transactionManager"/></property>
> > >
> > > <property name="target"><ref local="TestTarget"/></property>
> > >
> > >
> > > <property name="transactionAttributes">
> > > <props>
> > > <prop key="foo">PROPAGATION_REQUIRED</prop>
> > > </props>
> > > </property>
> > > </bean>
> > >
> > >
> > >
> > > When I invoke the method foo I get a ClassCastException
> >
> > Not sure why this is happening but you may need to create the
interceptor
> > chain manually to use a prototype, as TransactionProxyFactoryBean
propably
> > assumes it's dealing with a singleton. So you need to create a chain
that
> > includes:
> > - the name of your prototype
> > - the interceptor names, which may be singletons or prototypes as you
> > require. Use a prototype for mixin support.
> >
> > The following example comes from the test suite, with minor changes to
> make
> > it more obvious:
> >
> >
> > <bean id="prototypeTarget"
> > class="org.springframework.aop.interceptor.SideEffectBean"
> >  singleton="false">
> >  <property name="count"><value>10</value></property>
> > </bean>
> >
> > <!-- This can be a singleton or a prototype (for mixin behaviour) -->
> > <bean id="debugInterceptor"
> > class="org.springframework.aop.interceptor.DebugInterceptor">
> > </bean>
> >
> >
> > <bean id="prototype"
> >  class="org.springframework.aop.framework.ProxyFactoryBean">
> >  <!-- will automatically create invoker interceptor for the
prototype -->
> >  <property
> >
>
name="interceptorNames"><value>debugInterceptor,prototypeTarget</value></pro
> > perty>
> >
> > <!-- Note this -->
> >  <property name="singleton"><value>false</value></property>
> > </bean>
> >
> > There is a bug in M2 to do with prototype AOP handling, which is fixed
in
> > the forthcoming M3. However I don't think it should affect you in such a
> > simple usage.
> >
> >
> > Regards,
> > Rod
> >
> >
> >
> >
> > -------------------------------------------------------
> > This SF.net email is sponsored by: SF.net Giveback Program.
> > Does SourceForge.net help you be more productive?  Does it
> > help you create better code?  SHARE THE LOVE, and help us help
> > YOU!  Click Here: http://sourceforge.net/donate/
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
> -------------------------------------------------------
> This SF.net email is sponsored by: SF.net Giveback Program.
> Does SourceForge.net help you be more productive?  Does it
> help you create better code?  SHARE THE LOVE, and help us help
> YOU!  Click Here: http://sourceforge.net/donate/
> _______________________________________________
> Springframework-developer mailing list
> Spr...@li...
> https://lists.sourceforge.net/lists/listinfo/springframework-developer
>
>
> -------------------------------------------------------
> This SF.net email is sponsored by: SF.net Giveback Program.
> Does SourceForge.net help you be more productive?  Does it
> help you create better code?  SHARE THE LOVE, and help us help
> YOU!  Click Here: http://sourceforge.net/donate/
>
>
>
>
>
>
>
> -------------------------------------------------------
> This SF.net email is sponsored by: SF.net Giveback Program.
> Does SourceForge.net help you be more productive?  Does it
> help you create better code?  SHARE THE LOVE, and help us help
> YOU!  Click Here: http://sourceforge.net/donate/
> _______________________________________________
> Springframework-developer mailing list
> Spr...@li...
> https://lists.sourceforge.net/lists/listinfo/springframework-developer
>