Class / Component Diagram Content

[Andy Fisher]

I'm confused about what should go into the class and component diagrams?

In my class diagram, I�ve not only put my classes, interfaces and their relationships, but I�ve also added the subclasses for the �framework� classes I�m needing and any �pattern-orientated� classes (e.g. Fa�ade, Transfer Objects, Service Locators, etc., etc.).

However, from reading the threads in this forum, it seems as though most people are just concentrating (and scoring highly as a result) on representing the core (about 15-20) �model� classes.

Is this correct, and if so, won�t there be a few �isolated�, standalone classes?

Also, should the J2EE patterns that I�m using go into the Component Diagram???

�if so, is it acceptable to have the components (i.e. EJBs) alongside basic classes (as in Figure 4 of the following link: http://www.agilemodeling.com/artifacts/componentDiagram.htm), and should I be creating several component diagrams � i.e. one for each component?

[Dan Drillich]

Hi Andy,

The concept is pretty simple - the class diagram shows the model, almost in an abstract way while the component diagram shows your J2EE implementation of the entire solution.

You are asking about the relationships between the classes in the class diagram and the components in the component diagram. All kinds of relationships might exist. Keep as is, for example - the class remains a POJO in the end solution. Multiple classes end up as a composite entity in the component diagram, etc.

In my opinion, getting this concept right is a major objective of the exam, and therefore, I guess, it was not spelled out in the assignment.

Regards,
Dan

[Enn Ares]

Figure 11.10 in

http://java.sun.com/blueprints/guidelines/designing_enterprise_applications_2e/app-arch/app-arch5.html

has hints for a component diagram.

and Figure 11.9

has hints for a class diagram.

The component diagram above highlights "J2EE services" like JMS etc. whereas the class diagram highlights "J2EE coponents" like Servlets, EJBs etc

I would improvise the component diagram by including dotted-line arrows to show component dependencies. For the class diagram I would improvise by including BO methods that implement a Use Case.
[ February 01, 2007: Message edited by: Enn Ares ]