Re: Design question - implentation and composition

Hmmm, the word for implementing an interface has slipped my mind, anyway.

I have a design where it seems appropriate to use a tactic I haven't
seen before.

I've got four classes each of which subclass a common super class. There
are four interfaces which are divided into two groups. Each of the sub
classes must implement one interface from each group. However this has
meant that I have had some code duplication. This duplication is only
simple, a couple of setters and getters, at most any method is 4 lines long.

However, it seems appropriate to reuse the code because it /is/
identical and always should be. So the thought comes to mind that I
implement each of the interfaces with a separate class. I then contain
an instance of the two required implementations in each of the four
subclasses, while also still implement the two interfaces and the
methods just become wrappers around the instances of the implementations
of the interfaces.

The question:
Is this a strange design? Is there a better way to do it?

In fact the design is more complicated, it implements the abstract
factory pattern providing two factory methods. There is also a subclass
of each of the four classes which provides additional functionality
again, each subclass implementing a new interface.

Thanks

Lionel.