Java abstract class and overriding variables

Question

I have encountered a problem which I cannot solve. Let's say we have the superclass A:

public enum Enumeration {
  A, B, C;
}

public abstract Class A {
     private Enumeration e;

     public void someMethod {
           // do something here with 'e'.
     }
}

Now let's assume we have an class B.

public Class B extends A {
    private final Enumeration = e.A;
}

Here I get a compiler warning that the value is never used.

I just want to define the method in Class A, thus I have to define the variable. But I want to give the variable a new fixed value in the subclass.

Is this not possible?

Answer 1

Field can't be overridden. If you want to assign a specific enum instance to the class, use the constructor:

public abstract Class A {
     private final Enumeration e;

     protected A (Enumeration e) {
         this.e = e;
     }

     public void someMethod {
           // do something with 'e'.
     }
}

public Class B extends A {
    public B() {
        super(Enumeration.A);
    }
}