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");

}

}