0923-----In class to practive---about polymorphism and the primary of instanceof

package com.kai.li;

/**
  *
  */
public class FlyText{
    public static void main(String[] args){
        Plane p = new Plane();
        Bird b = new Bird();
        makeFly(p);
        makeFly(b);
        makeFly("dddkkdkdk");
        makeFly(20.5);
        makeFly(new Object());
    }
    public static void makeFly(Object o){
        if(!(o instanceof ICanFly))
            System.out.println("I can't fly.");
        else 
            ((ICanFly)o).fly();
    }
}

package com.kai.li;
/**
  * 
  */
public interface ICanFly{
    void fly();
}

package com.kai.li;

/**
  *
  */
public class Plane implements ICanFly{
    public void fly(){
        System.out.println("I am a plane,I can fly.");
    }
}

package com.kai.li;

/**
  *
  */
public class Bird implements ICanFly{
    @Override
    public void fly(){
        System.out.println("I am a bird,I can fly.");
    }
}