I have been fighting with one of the java specialist about where about the Business Delegate component should be.
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….
In a JSF application, the business delegate would be packaged along with the JSF code. So, that would be presentation?
does it means that the J2EE pattern diagram is wrong?
Plus, that's just my opinion. That doesn't mean I'm right. :P
Here's an interesting read:
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.
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.
Anyway, these patterns must be read very, very well because it is so easy to confused them...
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...