Interface (two methods, different return types depending on class) Java

Question

Any class that extends an interface must implement the methods declared in the interface. Not sure if this is possible but what I want to do is the following :

Answer 1

No, it's not possible. The interface serves as a "binding contact" of the signatures that are available.

If you want you can have the function return an Object and by that allow different implementations to return values of different types, but:

1. It must be references, not primitives.
2. You loose type safety at the call site.