マルチレベル継承を使用したJavaランタイムポリモーフィズム

例

class Animal {
   public void move() {
      System.out.println("Animals can move");
   }
}
class Dog extends Animal {
   public void move() {
      System.out.println("Dogs can walk and run");
   }
}
class Puppy extends Dog {
   public void move() {
      System.out.println("Puppy can move.");
   }
}
public class Tester {
   public static void main(String args[]) {
      Animal a = new Animal(); // Animal reference and object
      Animal b = new Puppy(); // Animal reference but Puppy object
      a.move(); // runs the method in Animal class
      b.move(); // runs the method in Puppy class
   }
}

Animals can move
Puppy can move.