Re: [Springframework-developer] Prototype handling support

[Colin S. <col...@ex...>]

Rod,

I am almost done a much simpler interimn (aka not as good) solution, 
which is a FactoryBeanCreatingFactoryBean.

It is simply a FactoryBean which produces a FactoryBean which will then 
be used for accessing a prototype. So you have the current definition.

    <bean id="prototype" class="a.b.c.D" singleton="false">
      ...
    </bean>
    <bean id="myX" class="a.b.c.XXX">
      ...
    </bean>

and the current java code

class XXX implements BeanFactoryAware {
    BeanFactory _bf;
    void setBeanFactory(BeanFactory beanFactory) throws BeansException 
{  ...  };

    ... in some method
    D dInstance = _bf.getBean("prototype");
    ...
}

This would become:

    <bean id="prototypeTarget" class="a.b.c.D" singleton="false">
      ...
    </bean>
    <bean id="prototype" 
class="org.springframework.beans.factory.config.FactoryBeanCreatingFactoryBean"> 

      <property name="targetName"><idref 
local="prototypeTarget"/></property>
    </bean>
    <bean id="myX" class="a.b.c.XXX">
      <property name="prototypeFactory"><ref local="prototype"/></property>
    </bean>

with the Java code:

class XXX  {
    FactoryBean _prototypeFactory;
    void setPrototypeFactory(FactoryBean factoryBean) {  ...  };

    ... in some method
    D dInstance = (D) _prototypeFactory.getObject();;
    ...
}

Now is the second form better? Personally I think so; there is still a 
tie to Spring of course (FactoryBean), but at least it's not 
BeanFactoryAware, and the client can only get at one bean, not _any_ 
bean in the BeanFactory. It would be a lot simpler of course if the 
container itself could create the FactoryBean on the fly as part of the 
property setting.

Your solution is much nicer of course. I would be interested in using 
and polishing up your code, but I can't do it myself either until about 
1.5 to 2 weeks from now. We have a situation with an app running on "the 
most popular open-source EJB server" which has become intolerable due to 
unreliability in the face of increased usage, and I need to work to move 
my current CVS code to production next week.

Colin


Rod Johnson wrote:

>Colin
>
>When it gets into Spring depends on when I have time to 
>polish it. Basically that means some time in June. It 
>basically works and it's _very_ useful. (I keep thinking of 
>cool things to use it for: I kept boring Juergen and Alef 
>about it on Sunday morning :-) It also needs discussion with 
>at least Juergen about the extensions to the DTD. (100% 
>backward compatible, of course.) And to accommodate the 
>upcoming AspectJ integration in 1.0.3 (new feature but again 
>very useful!) it needs to be implemented in a slightly 
>different, more open way.
>
>If you want to take responsibility for completing it, in 
>conjunction with myself and Juergen to discuss how the slight 
>enhancements to the core IoC stuff should work, that would be 
>great! I could send you the code and tests today. 
>
>That way we will get it for 1.0.3, which would also be great. 
>Of course if you're on HEAD you could be using it by the end 
>of the week... As I said, it already works.
>
>Rgds,
>Rod
>---- Original message ----
>  
>
>>Date: Tue, 11 May 2004 09:05:59 -0400
>>From: Colin Sampaleanu <col...@ex...>  
>>Subject: [Springframework-developer] Prototype handling 
>>    
>>
>support  
>  
>
>>To: spr...@li...
>>
>>Rod,
>>
>>At the TSS Symposium you mentioned having done some code to 
>>    
>>
>allow the 
>  
>
>>appcontext to dynamically modify a class so that a create or 
>>    
>>
>getter 
>  
>
>>method within it could actualy be hooked up to a prototype 
>>    
>>
>bean within 
>  
>
>>the factory. What are your thoughts on adding this code in 
>>    
>>
>at this time? 
>  
>
>>It would actually be of use to me...
>>
>>Colin
>>
>>
>>
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>>
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>  
>
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>>    
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>developer
>  
>