Is it possible to override a superclass' method with a parameter extending the superclass' method parameter?

Question

Say I have a class like so:

abstract class Something {}

And it has a hierachy with classes extending it:

class FirstSomething e         


        

Answer 1

You can make the A class generic by specifying that the type can be Something or one of its subclasses (I've made the setSomething method abstract but you can provide an implementation if you want).

abstract class A  {
    public abstract void setSomething(T something);
}

Then force the type T to be the specific class you want in your subclasses.

class B extends A {
    @Override
    public void setSomething(FirstSomething something) {
        //Set the something
    }
}

class C extends A {
    @Override
    public void setSomething(SecondSomething something) {
        //Set the something
    }
}