OnJava8-Examples/interfaces/HorrorShow.java

// interfaces/HorrorShow.java
// <20>2016 MindView LLC: see Copyright.txt
// Extending an interface with inheritance.

interface Monster {
  void menace();
}

interface DangerousMonster extends Monster {
  void destroy();
}

interface Lethal {
  void kill();
}

class DragonZilla implements DangerousMonster {
  @Override
  public void menace() {}
  @Override
  public void destroy() {}
}

interface Vampire extends DangerousMonster, Lethal {
  void drinkBlood();
}

class VeryBadVampire implements Vampire {
  @Override
  public void menace() {}
  @Override
  public void destroy() {}
  @Override
  public void kill() {}
  @Override
  public void drinkBlood() {}
}

public class HorrorShow {
  static void u(Monster b) { b.menace(); }
  static void v(DangerousMonster d) {
    d.menace();
    d.destroy();
  }
  static void w(Lethal l) { l.kill(); }
  public static void main(String[] args) {
    DangerousMonster barney = new DragonZilla();
    u(barney);
    v(barney);
    Vampire vlad = new VeryBadVampire();
    u(vlad);
    v(vlad);
    w(vlad);
  }
}
/* Output: (None) */