What is the use of creating a constructor for an abstract class in Java?

Question

I would like to know what purpose a constructor for an abstract class serves; as we do not instantiate abstract classes, why would we ever need such a constructor?

Answer 1

If you have uninitialised final fields in an abstract class, you'll need to initialise them in a constructor.

E.g.

abstract class A {
    final int x;
}

will not compile without a constructor that assigns to x.