🚀 go-pugleaf

"Ralph Quapp" <-> wrote:
>I therefore wanted to 'remove' the B part of the instance. But 
>probably - even when it would be a valid construct - it would 
>not work as it still will behave polymorphic 

yes, there is (for good reason) *no* way to change the runtime-type of an object so you can't "remove" parts. What you can do 
is make use of Java's access control features - your special 
subclass would be, say, a private inner class of your "real" class so nobody else can "use" it. Like this:

public class RealClass {

  public RealClass() {
    //do nothing special
  }

  public static RealClass getNewInstance() {
    return new SpecialClass();
  }

  private static class SpecialClass extends RealClass {

    private SpecialClass() {
      doSpecialThings();
    }

    private void doSpecialThings() {
      System.out.println("this is behind the scenes");
    }
  }
  
}

public class RealClassUser {
  public static void main(String[] args) {
    RealClass aRealClass = RealClass.getNewInstance();
    //show the runtime-type
    System.out.println(aRealClass.getClass().getName());    
    //but nobody else can make use of SpecialClass anyway
  }
}

I am not sure if this is what you are after though ;-)

>The question is now, should the compiler issue some warning or 
>not. 

Your original code is illegal, so the compiler should issue an 
error. 

>I am wondering what kind of bytecode JBuilder generates. 
>How can I see that?

javap -c is for that.

Torsten