SCEA Part 2 - Delegate Layer Needed?

[Ranganathan Kaliyur Mannar]

Hi,
For the part 2, I am providing a JSF solution. So, the layer is like:
JSF--> Backing Bean --> Session Beans --> JPA

When I am designing an application, if I have to make it framework-independent, I would need to introduce another layer like:
JSF--> Backing Bean --> Business Delegate --> Session Bean --> JPA

So, in case, the client decides to move from JSF to say Swing or something else, the JSF and backing bean would drop off and the delegate will be directly called.

For the exam, its is enough for me to give a direct JSF solution and I don't need the delegate actually...

So, now, do I get marks for such layering? or will I lose marks for not having a delegate layer?

[ahmed fayed]

Delegate layer has many forces besides isolating the presentation from the business tiers, like exception translation, hiding the details of service creation, reconfiguration, and invocation retries from the clients...etc.

Although JSF can use EJB 3 annotation to call the session beans directly, but the other delegate forces makes it worth to use than the annotation option.

From my readings in this forum and other users' experience, the more patterns you include in your design the more points you get, also there are questions in part three about the used patterns and the reason of using it, and so it will be a good point to mention there.

[Ranganathan Kaliyur Mannar]

Thanks for your reply. Yah, I was looking at using annotations only. I think I would like to include another delegate layer.