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How many Class Diagrams?

 
Chih-Wei Lee
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Hi All:
Am I supposed to put every class in one big class diagram?
I will have package for model classes, another package for DAO classes and another package for session bean classes.
If I separate these packages in different class diagrams, how do I show the relationship between the classes in different packages?

Best,

Chris
 
Shinelin Samuel
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Hi,

I would prefer to have a class diagram that represents a functional flow, it would include all required classes (Model, DAO, session) for that function.

There by, I can have 'n' no of class diagrams, one for each function that covers everything.

Regards,
Shinelin
 
prathap venkata naga yelugula
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Hi ,
I feel According to our requirement we can build class diagrams.
there is no restrictions on that number how we have to draw.

Cheers!
Prathap.
 
Pawel Piwowar
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I think the entry from Humphrey Sheil blog answers your question : http://humphreysheil.blogspot.com/2009/06/slides-from-javaone-bof-on-scea-exam.html#c8421713752901304123
RE: fragmenting the class diagram, I genuinely advocate against this and do so quite strongly. Fragmentation by itself is not the issue, but almost all candidates who do fragment, never provide a joined-up view clearly showing that their multiple class diagram fragments fulfil the business problem laid out in the domain model. Specifically, they lose many marks because association and multiplicity information between entities.

Finally, I believe that the complexity of the assignments in the exam don't require fragmentation.


So, for me the answer is clear : For SCEA assignment its better to make single diagram, if you have a big number of classes which could not fit on one diagram, it could only indicate that your solution become to complex (for SCEA needs) and you should simply reduce the number of your classes.
I think it is better to create simple and elegant solution, without going to far into details, and making a huge project, containing many fragmented diagrams.
Of course in case of real projects such fragmentation is inevitable, however SCEA assignment is much simpler than real project and following SCEA authors tips is a good idea IMO.
 
Chih-Wei Lee
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Thank you all.
I really appreciate your response, it's very helpful.
My concern about the multiple diagram is

1. I can't show the big picture for entire system.
2. Some classes like BidRequest entity will appear in several diagrams if I create class diagram for each use case or work flow.
This may confuse your developer.
3. Some association and multiplicity are hard to present or even missing among these fragment class diagrams.

My conclusion is I will have a big class diagram and reduce as many as the number of classes I can.
This may sacrifice some extensibility for system but will definitely address the requirement from SCEA doc.

Best,

Chris
 
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