java-继承类练习

class TuXing 

package com.dong;
 
/**
 * @author Captain_Dong
 *
 * 这个类不能创建对象，原因：存在抽象方法，该方法无法工作
 * 如何才能使用？------>>>>进一步给出具体实现（到底是什么图形，我才能实现类）
 */
public abstract class TuXing {
    private String mingCheng;
    public abstract double Area();
    public abstract double zhouChang();
    public String getAbc(){
        return "11111111111aaaaaaaaaaa222222222222bbbbbbbb!";
    }
 
    public TuXing() {
    }
 
    //public abstract String pp();
    public String pp(){  //一般方法的重写
        return "";
    }
    public TuXing(String mingCheng) {
        this.mingCheng = mingCheng;
    }
 
    public String getMingCheng() {
        return mingCheng;
    }
 
    public void setMingCheng(String mingCheng) {
        this.mingCheng = mingCheng;
    }
 
    @Override
    public String toString() {
        return "TuXing{" +
                "mingCheng='" + mingCheng + '\'' +
                '}';
    }
}

 

public class JVXing

package com.dong;
 
public class JVXing extends TuXing{
    //添加新属性
    private double x;//长
    private double y;//宽
 
    //构造方法
 
    public JVXing(String mingCheng, double x, double y) {
        super(mingCheng);
        this.x = x;
        this.y = y;
    }
    public JVXing( double x, double y) {
        super("矩形");//父类构造方法调用
        this.x = x;
        this.y = y;
    }
 
    @Override
    public double Area() {
        return this.x*this.y;
    }
 
    @Override
    public double zhouChang() {
        return 2*(this.y+this.x);
    }
 
    public String pp(){   //获取矩形相关信息
        //super.getAbc();
        String ss;
        ss=super.getAbc()+"\n"+super.getMingCheng()+"的长为："+this.x+",宽为："+this.y+"\n"+
                "面积为："+this.Area()+",周长为："+this.zhouChang();
        return ss;
    }
}

 

public class Circle

package com.dong;
 
public class Circle extends TuXing{
 
    private  double r;
 
    public Circle(){
        super();
    }
    public Circle(String mingCheng, double r) {
        super(mingCheng);
        this.r = r;
    }
 
    public Circle(String s) {
    }
 
    @Override
    public double Area() {
       return Math.PI*Math.pow(this.r,2);
    }
 
    @Override
    public double zhouChang() {
        return 2*Math.PI*this.r;
    }
    public String pp(){
        String ss;
        ss="圆的面积为："+this.Area()+"周长为："+this.zhouChang();
        return ss;
    }
 
    public double getR() {
        return r;
    }
 
    public void setR(double r) {
        this.r = r;
    }
}

public class Test01

 

package com.dong;
 
public class Test01 {
    public static void main(String[] args) {
        JVXing jvXing2=new JVXing("矩形1",100,15);
 
        JVXing jvXing=new JVXing("第二个矩形",10,2);
        JVXing jvXing1=new JVXing(100,200);
 
        TuXing tuXing=new JVXing("矩形2",15,20);
        TuXing tuXing1=new JVXing("矩形3",15,30);
 
        System.out.println(tuXing.pp());
        System.out.println(tuXing1.pp());
 
        System.out.println(tuXing);
 
        Circle circle=new Circle("圆",100);
 
        TuXing tuXing2=new Circle("圆1"+100);
 
        System.out.println(tuXing1.pp());//调用的是矩形的方法（多态）自动识别对象的方法
        System.out.println(tuXing2.pp());//调用的是圆的方法（多态）
 
 
    }
}