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CMT and Integration Tier

 
Peter Vennel
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Hi,
Sorry if this question is out of context with SCBCD. I am fairly new to EJB.
Before preparing for SCBCD, I had started preparing for SCEA for some time. So I was referring to Core J2EE Patterns book (Alur, Crupi & Malks).
Now I have a question regarding EJBs. Suppose, if I wanted to go CMP route, does that mean that I can totally skip designing the 'Integration Tier' (as this will be handled by the container)
Can someone share some of their real project experience, going strictly CMP route.

Thanks.
Peter
[ December 18, 2003: Message edited by: Peter Vennel ]
 
Magnus Stattin
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Hello Peter
The Integration Tier as defined in Core J2EE Patterns will handle the persistence of objects into some kind of database. In EJB the persistence is handled by Entitybeans. These components are created by you but with some help from the container. The container will handle transactions and database synchronization and you won't have to write any SQL as you would have to otherwise.
How the persistence should work is not abstracted away by the container, only made a bit easier in situations where the business requirement are high and involving thing such as transactions and location transparancy.
Best Regards
/Magnus
 
Peter Vennel
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Thanks for the insight Magnus.
Now EJB's and other business objects are in the 'Business Tier'. So is the 'Container' functionality in Business Tier or the Integration Tier. Sorry, if I am confusing you. What I mean to ask is what tiers will the model have ?
Client - Presentation - Business

or

Client - Presentation - Business - Integration

One more question, is it prudent to have CMP in the entire system.

Thanks.
Peter
[ December 18, 2003: Message edited by: Peter Vennel ]
 
Magnus Stattin
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I'm not sure what you put in the integration tier. It seems more like a conceptual way of viewing the system. But maybe I don't understand what you mean.
Regards
 
Peter Vennel
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Brief outline of Integration Tier
"Integration tier mainly comprises of DAO. In order to increase data source independence and migration potential, Data Access Objects can be combined with the Abstract Factory pattern. The Abstract Factory creates different DAO instances depending on which data source and which entity to access. This makes it possible to reconfigure which data source should be used without reprogramming the application"
Now all this is handled by the Container. So am I technically right by saying that we can have a J2EE model, where functionality of the Integration Tier can be left to the Container by taking the CMP approach.
I need to present a J2EE model to my boss using CMP.
Any inputs appreciated.
Note: Earlier, I wrongly mentioned CMT instead of CMP.

Thanks.
Peter
[ December 18, 2003: Message edited by: Peter Vennel ]
 
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