Hi, 

I am hoping someone can clarify this one for me. 

I was reading O'Reilly's "Enterprise JavaBeans" book and was a bit confused by 
the following... 

It describes how there is such a thing as an EJB object. Remote and local 
interfaces are implemented by this object adding container specific code that 
handles transactions, security and so on. 

This EJB object also either extends the bean class or simply copies the code of 
the developer written bean class into itself. 

Now, comes along instance pooling and the book explains that this is done by 
associating a bean instance with this EJB object. So, the object is always 
around (or a number of them are around) and the container keeps associating the 
a bean instance from the bean instance pool with this EJB object whenever it is 
needed. 

What I don't understand is how this is possible. Two possibilities are given as 
to how vendors might implement the relationship between the EJB object and the 
bean instance. I described those 2 above. In both cases, the code of the bean 
becomes PART of the EJB object, whether through inheritance or through just 
coping and pasting the code from the bean into the EJB object class. 

How is it then possible to swap instances of the bean when it appears that the 
EJB object already contains that instance behavior within it? 

I could have understood this if EJB object would use some sort of a Factory 
pattern to get a handle on an instance of the bean, but that's not what it's 
doing in either implementation. 

I'd appreciate your help on this one. 

Thanks, 
Yaakov. 

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