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component diagram

 
Bess Moore
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Hi Ranches,
I have been fighting with one of the java specialist about where about the Business Delegate component should be.

http://www.corej2eepatterns.com/Patterns2ndEd/index.htm

According the J2ee Business Delegate is in the Business Tier but, the specialist keep insisting it should be in presentation Tier because is deployed in it….

So any comment….
 
Cameron Wallace McKenzie
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Some would say that in Java EE 5, there is no need for the business delegate.

In a JSF application, the business delegate would be packaged along with the JSF code. So, that would be presentation?

-Cameron McKenzie
 
Bess Moore
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padam my ignorant,
does it means that the J2EE pattern diagram is wrong?
 
Cameron Wallace McKenzie
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Well, J2EE and Java EE 5 are two different monsters.

Plus, that's just my opinion. That doesn't mean I'm right. :P

Here's an interesting read:

http://www.coderanch.com/t/156191/Architect-Certification-SCEA/certification/Obsolete-Design-Patterns-EJB-SCEA#2046797

-Cameron McKenzie
 
Maverick Grotto
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It depends on which layer you are going to use BusinessDelegate in.

Generally speaking a BusinessDelegate is used in the presentation layer, so that the presentation tier has access to the business functionality in a uniform, simplified manner. But there might be a case where one business component (A) has to call another business component (B). In this scenario, a business delegate to component B will reside in the business tier.

To simplify things, if we think in terms of client and server, the business delegate will always reside in the client.

The client could be residing in the presentation tier or the business tier.

But again generally speaking, Business delegate resides in the presentation tier.

I hope this helps.
 
Bess Moore
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Point made. I am now completely agreed that the business delegate component should be in presentation layer,

But does it means that interfaces of EJB3 behave as business delegate ??
i.e business delegate (EJB Interface) --> Business façade (EJB implementation) --> ……


I am so confuse now.
 
Octav Ioan
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I think business delegate must be present into client tier because in the pattern consequences said: It is easier to manage changes (on client I suppose) because they are centralized in one place, the Business Delegate.
Anyway, these patterns must be read very, very well because it is so easy to confused them...
 
Oricio Ocle
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Hello, here is a literal quote from the Core J2EE Patterns book


The Business Delegate (302) pattern is categorized as a business-tier pattern and not a presentation-tier pattern because the Business Delegate is a logical abstraction, not a physical one. When used with a presentation tier, the actual Business Delegate components live in the presentation tier. However, they are a logical extension of the business tier...


Regards
 
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