Re: [Springframework-developer] Singelton FactoryBeans are asked for an object before beanFactor.getBean(name) is called by application

[Cameron B. <ca...@da...>]

Colin Sampaleanu wrote:

> This is happening because AbstractApplicationContext foreces 
> singletons (which includes your FactoryBean) to be pre-instantiated. 
> This essentially calls getBean() on the bean, which ends up calling 
> getObject().
>
> Coincidentally, just a few days ago I asked here why singletons were 
> always preinstantiated, with no ability to turn off this behaviour, 
> but nobody commented... It probably makes sense to be able to turn 
> this off for specific beans.
>
I agree.

Wouldn't it make sense to not preinstantiate FactoryBeans that aren't 
singeltons (FactoryBean.isSingelton()=false) since this initial instance 
will be disposed of anyway.

Thanks,

Cameron.

> Regards,
> Colin
>
> Cameron Braid wrote:
>
>> I have a FactoryBean that is a singleton.  It is a prototype factory 
>> (is that correct terminoligy?)
>>
>> When the application context initialized, the FactoryBean.getObject() 
>> is being called before I call getBean() from my application.
>>
>> The problem is that the contract for BeanFactory.getObject() states 
>> that it shoud never be null.
>>
>>     /**
>>      * Return an instance (possibly shared or independent) of the object
>>      * managed by this factory. As with a BeanFactory, this allows
>>      * support for both the Singleton and Prototype design pattern.
>>      * @return an instance of the bean *(should never be null)*
>>      * @throws Exception in case of creation errors
>>      */
>>     Object getObject() throws Exception;
>>
>> Though in my application, I can't gaurantee this.  I am relying on 
>> source of information that doesn't exist until a servlet call is made.
>>
>> How come this happens, and is it necessary to create an instance that 
>> gets thrown away ?
>>
>> Cheers
>>
>> Cameron
>
>
>
>
>
>
>
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