polymorphism example

Animatable.java

package polymorphism;

public interface Animatable {
	void animate();
}	

GameShape.java

package polymorphism;

public class GameShape {
	public void displayShape() {
		System.out.println("displaying shape");
	}
	// more code
}

PlayerPiece.java

package polymorphism;

public class PlayerPiece extends GameShape implements Animatable {
	public void movePiece() {
		System.out.println("moving game piece");
	}

	public void animate() {
		System.out.println("animating...");
	}
	// more code
}

Test.java

package polymorphism;

public class Test {
	public static void main(String[] args) {
		// following are legal
		PlayerPiece player = new PlayerPiece();
		Object o = player;
		GameShape shape = player;
		// shape.movePiece-- this call will not work as methods on GameShape
		// only visible.
		
		// compiler is not aware of what actually object instance type is. at
		// runtime, jvm can identify object and then typecast works
		Animatable mover = player;
	}
}