How to assign super to a variable?

Question

I\'d like to do the following:

public class Sub extends Super {
  public Sub(Super underlying) {
    if (underlying == null) {
      underlying = super; // this          


        

Answer 1

I think something like what you want can be done if you are willing to add, and call, subclass-specific method names for the methods involved:

public class Test {
  public static void main(String[] args) {
    Super sup = new Super();
    Sub sub1 = new Sub(null);
    Sub sub2 = new Sub(sup);
    sub1.subMethod();
    sub2.subMethod();
    sup.method();
  }
}

class Super {
  public void method(){
    System.out.println("Using method from "+this);
  }
}

class Sub extends Super {
  private Super underlying;
  public Sub(Super underlying) {
    if (underlying == null) {
      underlying = this;
    }

    this.underlying = underlying;
  }

  public void subMethod() {
    underlying.method();
  }
}