Overall Architecture

[Nate Johnson]

I would agree with Michael... the main that that you need is one main interface so that the client can deal with one, and not care which mode it is in.

[CyJenny Wong]

Hi Nate & Michael,
Thanks for the reply. Now I understand of advantage of using just single interface. But I got another question is:
In the client Facade whenever client call those methods in the implementation class that implemented the DataInterface, client need to try & catch both RemoteException, DatabaseException etc. even if client's connection is LOCAL. Is there any other way to work around with this?

[Nate Johnson]

That is just what I did. Then I wrapped (with exception chaining) up the exceptions in a FBNException, with a useful message for the user. Then, my view only had to deal with one type of exception and display a nice pop-up to the user.
I would be interested in hearing other people's solutions to this as well.

[Michael Morris]

Pretty good exception handling Nate. What I did was have a catch block for each possible exception starting with the most specialized and ending with the generic Exception. Each block triggered a specific dialog based on the exception type.
Michael Morris

[CyJenny Wong]

That is just what I did. Then I wrapped (with exception chaining) up the exceptions in a FBNException, with a useful message for the user. Then, my view only had to deal with one type of exception and display a nice pop-up to the user.

Hi Nate,
Can you give me one example of how you did the above.

[Nate Johnson]

First you need to know what exception chaining is, so here is a good start on that...
Author: Brian Goetz
Article: Exceptional practices, Part 2
http://www.javaworld.com/javaworld/jw-09-2001/jw-0914-exceptions-p2.html
Exception chaining is provided by JDK 1.4, but I emailed Sun and they told me not to use 1.4, so I had to use Brian's class to get the same out of 1.3.
Ex:

try {
    // ...
} catch(DatabaseException de) {
    throw new FBNExeption("There are problems with the database...", de);
} catch (RemoteException re) {
    throw new FBNExeption("There are problems with the network...", re);
}

and then catch the FBNExceptions in your view and display an nice pop-up with the message from the exception.

The really nice thing about chaining exceptions is that you keep appending the stack traces on to each other and you will have a great debugging report to give back to the developers when problems occur (that is if you code has a bug in it )
Hope that helps...
[ August 17, 2002: Message edited by: Nate Johnson ]

[CyJenny Wong]

Hi Nate,
So where should I packaged the FBNExeption & ChainedException classes?