Is it possible to override only required abstract methods in interface or Abstract classes among n-methods?

Question

Is it possible to override only some abstract methods in interface among set of abstract methods?

Answer 1

Yes you can provided you make that class also as abstract.

Answer 2

Is it possible to override only some abstract methods in interface

Yes, but since the resulting class is still not fully concrete, this class has to be declared abstract.

This compiles fine:

interface MyInterface {
    void method1();
    void method2();
}

abstract class MyClass implements MyInterface {
    public void method1() { }
}

(but it won't compile without the abstract modifier).