定义一个接口Shape，包含两个方法：计算表面积area()和计算体积volume()定义圆柱体类Cylinder和圆类Circle，其中Circle类是Cylinder类的内部类Circle类中创建成员变量double radius和全参构造方法，创建两个成员方法：计算圆面积public double area()和圆周长public double perimeter()；Cylinder类创建两个成员变量：Circle类型的circle和double类型的height，创建全参构造方法，并通过实现Shape接口求圆柱体的表面积和体积创建DemoCylinder测试类，在main方法中先创建Circle内部类对象，然后用该对象创建Cylinder对象并调用方法求半径为5高为10的圆柱体的表面积和体积 public interface Shape { double area(); double volume();} public class Cylinder implements Shape{ Circle circle; double height; static class Circle{ //补充内部类代码 double radius; } //补充外嵌类代码 } public class DemoCylinder { public static void main(String[] args) { //补充测试类代码 }}

代码如下：

public interface Shape {
    double area();
    double volume();
}

public class Cylinder implements Shape{
    Circle circle;
    double height;
    
    public Cylinder(Circle circle, double height) {
        this.circle = circle;
        this.height = height;
    }
    
    @Override
    public double area() {
        return 2 * Math.PI * circle.radius * (circle.radius + height);
    }

    @Override
    public double volume() {
        return Math.PI * circle.radius * circle.radius * height;
    }
    
    static class Circle{
        double radius;
        
        public Circle(double radius) {
            this.radius = radius;
        }
        
        public double area() {
            return Math.PI * radius * radius;
        }
        
        public double perimeter() {
            return 2 * Math.PI * radius;
        }
    }
}

public class DemoCylinder {
    public static void main(String[] args) {
        Cylinder.Circle circle = new Cylinder.Circle(5);
        Cylinder cylinder = new Cylinder(circle, 10);
        
        System.out.println("圆柱体的表面积为：" + cylinder.area());
        System.out.println("圆柱体的体积为：" + cylinder.volume());
    }
}