An alternative to the observed sample?

Question

I need to perform some tasks on object1when some kind of state change occurs on object2. I tried to use the observed pattern in android, I mean to use the classes Observer and Observable, therefore object1implements Observer and object2extends Observable. Unfortunately, it object2already extends from another class, so I cannot define it as an extension of Observable.

Is there any other alternative to using this template? Maybe other classes that allow me to execute this behavior?

Thank.

Answer 1

object2 Observable, , notifyObservers(), - .

, " ".

Answer 2

Observable , , .

Observable . Listener

Observable addListener(Listener listener) removeListener(Listener listener)