Java 各种形状的面积与周长(继承）

Java 各种形状的面积与周长(继承）
面向继承与多态编程思想：代码如下：

public class GeometricManage {
    public static void main(String[] args) {
        Circle c01 = new Circle(10);
        Rectangle r01 = new Rectangle(10,5);
        System.out.printf("圆的面积为：%.2f,圆的周长为：%.2fn",c01.getArea(),c01.getPerimeter());
        System.out.printf("矩形的面积为：%.2f,矩形的周长为：%.2fn",r01.getArea(),r01.getPerimeter());
    }
}

 class GeometricObject{
    private String color;
    private Boolean filled;
    private Date dateCreated;

    // 构造函数
    protected GeometricObject(){
        dateCreated = new java.util.Date();
    }

    protected GeometricObject(String color,boolean filled){
        dateCreated = new java.util.Date();
        this.color = color;
        this.filled = filled;
    }

    // 参数返回修改方法
    public String getColor(){
        return color;
    }

    public void setColor(String color){
        this.color = color;
    }

    public boolean isFilled(){
        return filled;
    }

    public void setFilled(boolean filled){
        this.filled = filled;
    }

    public java.util.Date getDateCreated(){
        return getDateCreated();
    }

    

    // 方法 1.计算面积  2. 计算周长
    public double getArea() {
        return 0;
    }

    public double getPerimeter() {
        return 0;
    }
}

class Circle extends GeometricObject{
    private double radius;
    public Circle(){
    }
    public  Circle(double radius){
        this.radius = radius;
    }
    public Circle(double radius,String color,boolean filled){
        this.radius = radius;
        setColor(color);
        setFilled(filled);
    }

    // 参数返回修改方法
    public double getRadius(){
        return radius;
    }

    public void setRadius(double radius){
        this.radius = radius;
    }

    // 继承父类
    public double getArea(){
        return radius*radius* Math.PI;
    }

    public double getPerimeter(){
        return 2*radius*Math.PI;
    }
}

class Rectangle extends GeometricObject{
    private double length;
    private  double width;

    // 构造函数
    public Rectangle(){
    }

    public Rectangle(double length,double width){
        this.length = length;
        this.width = width;
    }

    public Rectangle(double length,double width, String color,boolean filled){
        this.length = length;
        this.width = width;
        setColor(color);
        setFilled(filled);
    }

    // 参数返回修改方法
    public double getLength(){
        return length;
    }

    public void setLength(double length){
        this.length = length;
    }

    public double getWidth(){
        return width;
    }

    public void setWidth(double width){
        this.width =width;
    }

    // 继承父类
    public double getArea() {
        return length*width;
    }

    public double getPerimeter(){
        return 2*(length+width);
    }
}
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