About that JDeveloper extension to generate a decorator, maybe this is worth a look:
see https://jdevcextensions.samplecode.oracle.com/download/DecoratorJCE/index.html

regards
Jan Vervecken

How would u like to be specifying the interface or abstract class name to generate the implementation class as per your needs?

OK, that is pretty seriously cool, and makes me want to learn Groovy much better than I know it. I’d very much thought of its advantages as being that the script is a bit easier to write than Java, but the “meta-programming” described in that article makes it clear that it has some serious structural abilities. The ability to basically write a decorator-by-exception (that is, a decorator that just invokes most methods on the decoratee, but makes exceptions for particular methods) without having to implement every single one of the plain invocations, which is essentially what I would need, is pretty powerful. I’ll look into it.

For those who don’t want to use Groovy, of course, I’d still think that the ability to generate a Java stub for the design pattern would be really nice. Lots of people (though not, I think, me) might find the cost of learning yet another technology–reasonably well, since this doesn’t look like it’d be in your standard 8-hour “Groovy for business logic” tutorial–too high for the advantages.

Thanks much,
Avrom

Although a JDeveloper extension could be useful here, you could also ask for more Groovy support in JDeveloper because Groovy seems to provide some interesting approaches for a decorator, see http://groovy.codehaus.org/Decorator+Pattern .

regards
Jan Vervecken