Mu Mike wrote:
> dont you think this is too strict?
nah, not really :D. There are *loads* of reasons to always only use
interfaces when defining communication between components. Avalon
enforces it. You'll get behaviour like this in fortress, merlin,
phoenix, various AOP frameworks (like nanning) and other containers (IoC
or not).
> every implementaion of a Service must have all its public methods
> declared in the interface,and if you happen to need to add a public
> method to a specific implemetation class, you must declare it in the
> Interface,and since other implementations may need not use that method,
> you will have to have an abstract class also,just such a right rule.
>
> no need and no way to break the rule?
generally, nope. It's designed to be unbreakable. That said, you could
modify fortress and plug in a proxy manager/factory that doesn't do the
proxying, but I'm not too sure how atm. Nor should you want to :D
If a specific implementation class exposes a method not in the
interface, then you can't freely "hot-swap" different implementation
classes anyway. And if you can't hot swap, that means that your
components have different work interfaces. And if they have different
work interfaces, you should make your "client components" know about the
difference.
The solution to your specific issue is probably (can't be sure since I'm
not writing your app :D) to add a more specific work interface, and use
that:
public interface Thing // basic work interface
{
void doStuff();
}
public interface ExtendedThing extends Thing // has the extra method
{
void doOtherStuff();
}
public class MyThing implements Thing { /* ... */ }
public class MyPowerThing implements ExtendedThing { /* ... */ }
// in the client...
public void service( ServiceManager sm ) throws ServiceException
{
if( !sm.contains( ExtendedThing.ROLE ) )
{
log.warn("degraded service...no " + ExtendedThing.ROLE +
" available!");
Thing mything = sm.lookup( Thing.ROLE );
}
}
hope this helps! (if it does, I'd appreciate someone adding this to our
online-editable FAQ at http://wiki.apache.org/avalon/AvalonFAQ)
cheers,
-LSD
---------------------------------------------------------------------
To unsubscribe, e-mail: [EMAIL PROTECTED]
For additional commands, e-mail: [EMAIL PROTECTED]
