java中面向对象三大思想（继承、封装、多态）简单应用

package cn.com.chapter1.technolgy;

public class PlayBall {


public static void main(String[] args) {
Ball ball=null;
ball=new Basketball();//多态1
play(ball);
ball=new Football();//多态2
play(ball);


}
   public static void play(Ball ball)
   {
  if("basketball".equals(ball.getName()))
  System.out.println("这是篮球类");
  else if("football".equals(ball.getName()))
  System.out.println("这是足球类");
   }

}

 class Ball {
    private String name;
    public Ball(){
    System.out.println("\t父类无参构造方法");
    }
    public String getName()
    {
    return name;
    }
    public void setName(String name)
    {
    this.name=name;
    }

}

class Basketball extends Ball{ //继承1
public Basketball()
{
super();
System.out.println("\t子类(篮球)无参构造方法");
super.setName("basketball");
}

}

class Football extends Ball{   //继承2
public Football()
{
super();
System.out.println("\t子类(足球)无参构造方法");
super.setName("football");
}
}