5.7JAVA笔记

一，Java课后题

6.4.1

父类

package cn.com.sict_01;
​
public abstract class Player {
    private String name;
    private int age;
    public Player() {}
    public Player(String name,int age) {
        this.name = name;
        this.age = age;
    }
    public String getName() {
        return name;
    }
    public void setName(String name) {
        this.name = name;
    }
    public int getAge() {
        return age;
    }
    public void setAge(int age) {
        this.age = age;
    }
    
    public abstract void testPlay();//子类全部要重写抽象方法，必须加abstract
}
​

篮球类

package cn.com.sict_01;
​
public class BasketballPlay extends Player {
    public BasketballPlay() {
        super();
    }
    public BasketballPlay(String name,int age) {
        super(name,age);
    }
    @Override
    public void testPlay() {
        // TODO Auto-generated method stub
        System.out.println("该篮球运动员正在投篮......");
    }
    
​
}

测试类

package cn.com.sict_01;
​
public class PlayDemo {
​
    public static void main(String[] args) {
        // TODO Auto-generated method stub
        Player p1 = new BasketballPlay();
        p1.testPlay();
        p1.setName("姚明");
        p1.setAge(38);
        System.out.println(p1.getName()+"---"+p1.getAge());
        
        Player p2 = new BasketballPlay("易建联",30);
        System.out.println(p2.getName()+"---"+p1.getAge());
        p2.testPlay();
    }
​
}
​

6.4.3

父类

package cn.com.sict_03;
​
public interface Measurement {
    public abstract void area();
    public abstract void Perimeter();
}
​

几何图形类

package cn.com.sict_03;
​
public abstract class Shape implements Measurement {
    private int line1;
    private int line2;
    public Shape() {}
    public Shape(int line1) {
        this.line1 = line1;
    }
    public Shape(int line1, int line2) {
        this.line1 = line1;
        this.line2 = line2;
    }
    public int getLine1() {
        return line1;
    }
    public void setLine1(int line1) {
        this.line1 = line1;
    }
    public int getLine2() {
        return line2;
    }
    public void setLine2(int line2) {
        this.line2 = line2;
    }
}
​

实现矩形类

package cn.com.sict_03;
​
public class Rectangle extends Shape{
    public Rectangle() {
        super();
    }
    public Rectangle(int line1,int line2) {
        super(line1,line2);
    }
    @Override
    public void area() {
        // TODO Auto-generated method stub
        System.out.println("面积是:"+(super.getLine1()*super.getLine2()));
    }
​
    @Override
    public void Perimeter() {
        // TODO Auto-generated method stub
        System.out.println("周长是:"+(super.getLine1()+super.getLine2())*2);
    }
    
}

测试类

package cn.com.sict_03;
​
public class ShapeDemo {
​
    public static void main(String[] args) {
        // TODO Auto-generated method stub
        Shape s1 = new Rectangle();
        s1.setLine1(3);
        s1.setLine2(4);
        s1.area();
        s1.Perimeter();
        System.out.println("----");
        Measurement s2 = new Rectangle(5,6);
        s2.area();
        s2.Perimeter();
    }
}