OnJava8-Examples/references/HorrorFlick.java

// references/HorrorFlick.java
// <20>2016 MindView LLC: see Copyright.txt
// We make no guarantees that this code is fit for any purpose.
// Visit http://mindviewinc.com/Books/OnJava/ for more book information.
// You can insert Cloneability
// at any level of inheritance.

class Person {}

class Hero extends Person {}

class Scientist extends Person
implements Cloneable {
  public Object clone() {
    try {
      return super.clone();
    } catch(CloneNotSupportedException e) {
      // Should never happen; it's Cloneable:
      throw new RuntimeException(e);
    }
  }
}

class MadScientist extends Scientist {}

public class HorrorFlick {
  public static void main(String[] args) {
    Person p = new Person();
    Hero h = new Hero();
    Scientist s = new Scientist();
    MadScientist m = new MadScientist();
    //! p = (Person)p.clone(); // Compile error
    //! h = (Hero)h.clone(); // Compile error
    s = (Scientist)s.clone();
    m = (MadScientist)m.clone();
  }
}
/* Output: (None) */