Java实现方法覆盖：圆形和圆柱面积计算

import java.util.Scanner;

abstract class Shape { public abstract double area(); }

class Circle extends Shape { private double radius;

public Circle(double radius) {
    this.radius = radius;
}

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

}

class Cylinder extends Circle { private double height;

public Cylinder(double radius, double height) {
    super(radius);
    this.height = height;
}

public double area() {
    return 2 * super.area() + 2 * Math.PI * super.radius * height;
}

}

public class Test { public static void main(String[] args) { Scanner scanner = new Scanner(System.in); System.out.print('请输入圆的半径：'); double r = scanner.nextDouble(); Circle circle = new Circle(r); System.out.println('圆的面积为：' + circle.area());

    System.out.print('请输入圆柱的半径：');
    r = scanner.nextDouble();
    System.out.print('请输入圆柱的高：');
    double h = scanner.nextDouble();
    Cylinder cylinder = new Cylinder(r, h);
    System.out.println('圆柱的表面积为：' + cylinder.area());
}

}