super in static context

[David Duran]

Is there anyway to reference a subclass's superclass using the "super" keyword within a static context?
For Example:

public Subber extends Supper
{
   public static int a = super.STATIC_INT;  // I want this!
   public static int b = Supper.STATIC_INT; // I don't want this
}

[Michael Morris]

Hi David,

Is there anyway to reference a subclass's superclass using the "super" keyword within a static context?

No, because super is a reference to an instantiated object which is non-static. If you call it from a static (class scope) context, which instance of super are you referring to? Even though the member you may be referring to is indeed static, how can you expect the compiler to resolve the reference to super?
Michael Morris

[Garrett Smith]

Have you thought about using a method to get the value of the subclass? The method could be called on any class that is a Supper.

interface Supper{
    int STATIC_INT = 'a';
    
    int getStaticInt();
    
}
public class Subber implements Supper {

   private static int SUB_STATIC_INT = STATIC_INT;
   
    public int getStaticInt(){
        return STATIC_INT;
    }
}

[Cindy Glass]

Actually - yes.
If a sub-class has a static variable x that hides a variable x of the same name in the super class, preventing it from being inherited, then one of the acceptable syntax forms for getting at the super classes variable is
super.x;
This is exactly equivalent to using
Supper.x;
See the JLS: 8.3.3.1 Example: Hiding of Class Variables

[Cindy Glass]

Heck - even if you did NOT hide it in the sub-class and could legitamately use the simple variable name x you are still ALLOWED to use the super.x syntax it you choose.

[Michael Morris]

Heck - even if you did NOT hide it in the sub-class and could legitamately use the simple variable name x you are still ALLOWED to use the super.x syntax it you choose.

But you still can't refer to super or this from a static context. I thought that was what the original question was all about, not member hiding.
You can do this :

public class Subber extends Supper {
    public static int STATIC_INT = 13;
    private static int a;
    public Subber() {
        super();
        a = super.STATIC_INT;
    }
    ...

But you can't do this:

public class Subber extends Supper {
    public static int STATIC_INT = 13;
    private static int a = super.STATIC_INT;
    public Subber() {
        super();
    }

   ...

Michael Morris

[Cindy Glass]

Duh! Oh, that "from a static context" part :roll: . (Of course that IS what his example showed - sigh).
So you are correct - to do it you would need something not in a static context like:

public class Supper
{
   public static int STATIC_INT = 11;
   
}
public class Subber extends Supper
{
   public static int STATIC_INT = 22;
   public int a = super.STATIC_INT;  // not static
   public static int b = Supper.STATIC_INT; // I don't want this
   public static void main(String args[]){
Subber sub = new Subber();
System.out.println("STATIC_INT = " + STATIC_INT);
   System.out.println("super.STATIC_INT = " + sub.a);
   System.out.println("Supper.STATIC_INT = " + b);
   }
}

[ March 04, 2003: Message edited by: Cindy Glass ]