File APIs for Java Developers
Manipulate DOC, XLS, PPT, PDF and many others from your application.
The moose likes Architect Certification (SCEA/OCMJEA) and the fly likes Query : Component Diagram Big Moose Saloon
  Search | Java FAQ | Recent Topics | Flagged Topics | Hot Topics | Zero Replies
Register / Login
JavaRanch » Java Forums » Certification » Architect Certification (SCEA/OCMJEA)
Bookmark "Query : Component Diagram" Watch "Query : Component Diagram" New topic

Query : Component Diagram

Sankar Th

Joined: Jul 09, 2012
Posts: 9
I have kept Stateless SB at Business logic layer. I have a DAO and DAOImpl where JPA Enitity manager gets created and the respective Entities as well.
1)As DAO comes under Integration pattern , I have put DAO components under Integration tier.
2)But ,I have a another view that , as these DAOs are associated to persistence context ,this shall be put under persistence tier which can be clubbed together with Business logic tier and can be addressed as one Business Logic & Persistence tier. No need for integration tier ?

I feel it's a thin line to distinguish .Your thoughts please ?
Fernando Franzini
Ranch Hand

Joined: Jan 09, 2009
Posts: 489

Hi Sankar

As an architect you are free to design in a way that you see fit. Just remember that you need to justify their decisions. So there's no way to answer this kind of question.

For example: I disagree with you:
Stateless SB can't be business layer! If you do your business layer as Stateless SB, you'll be tying the rules of business of the solution in the EJB technology. In my opinion as an architect, a business rule should be written in Java as Pure POJO.
As I told you, every architect has their point of view.

If you need to study design issues, I advise you to read books on the subject:
1. POJO in Action Book by Chris Richardson Book.
2. Domain Drive Design by Erick Vans Book.
3. Patterns of Enterprise Application Architecture by Martin Fowler Book.

Best Regard.

Fernando Franzini - Java Blog
Aditya Kumar
Ranch Hand

Joined: Oct 31, 2006
Posts: 102
Stateless SB can't be business layer!

While searching through the forum I chanced upon this and it sort of took me by surprise. While I do understand that the Session beans (Stateful/Stateless) are meant to encapsulate the business logic of the application - where do you think they stand to be in the component diagram? Is it unacceptable to put the EJBs in the business layer in the component diagram? This confuses me.

Which brings me to my second question - Is the component diagram supposed to show the classes that I have used in the class diagram? I thought it is supposed to be a level "above" the class diagram (which probably means that I'd make "boxes" that could house those classes without naming them) - Or is it a common, acceptable (and risk-free) practice to liberally show the classes and their stereotypes in the component diagram?

I agree. Here's the link:
subject: Query : Component Diagram
jQuery in Action, 3rd edition