Java-圆柱体程序-无法使用main

我太迷茫了，我都不知道该问什么问题了。我有一个程序，它应该能够用半径和高度来构造一个圆柱体。然后，它应该能够调用各种方法来获取和设置半径以及输出表面积和体积。我无法通过go，因为我无法在main中放入任何内容，而不会出现关于在static中使用静态非静态方法的错误。我甚至不知道那是什么意思。实际上，我将其他人的代码复制到我的编译器中，它会给我同样的错误。我是不是搞砸了什么？我知道这对于堆栈溢出来说可能太简单了，但我现在非常绝望

public class Miller_A03Q1 {

    public static void main(String[] args) {
        Cylinder cylinder1 = new Cylinder(1,17);
        Cylinder cylinder2 = new Cylinder(3,8);
        Cylinder cylinder3 = new Cylinder(2,12);
        Cylinder cylinder4 = new Cylinder (1,14);    
    }

    public class Cylinder{
        private double radius = 0.0;
        private double height= 0.0;
        private double area = 0.0;
        private double volume=0.0;
        private String shape = "cylinder";


        public Cylinder(double r,double h){
            this.radius = r;
            System.out.print(r);
            this.height = h;
            System.out.print(h);

        }
        public double getVolume(){
            double volume = 3.14 * radius * radius * height;
            return volume;
        }
        public double getArea(){
            double circumference = 3.14 * 2 * radius;
            double circleArea = 3.14 * radius * radius;
            double area = (2 * circleArea) + (circumference * this.height);
            return area;
        }
        public double getRadius(){
            return this.radius;
        }
        public double getHeight(){
            return this.height;
        }
        public void setHeight(double h){
            this.height = h;
        }
        public void setRadius(double r){
            this.radius = r;
        }
        @Override
        public String toString(){
            return this.shape + this.radius + this.height+ this.volume + this.area;
        }            
    }       
} 

---

我不知道您是否需要外部类，但如果您只是将main方法放在它为我编译的圆柱体类中

public class Cylinder {
    private double radius = 0.0;
    private double height = 0.0;
    private double area = 0.0;
    private double volume = 0.0;
    private String shape = "cylinder";

    public Cylinder(double r, double h) {
        this.radius = r;
        System.out.print(r);
        this.height = h;
        System.out.print(h);

    }

    public double getVolume() {
        double volume = 3.14 * radius * radius * height;
        return volume;
    }

    public double getArea() {
        double circumference = 3.14 * 2 * radius;
        double circleArea = 3.14 * radius * radius;
        double area = (2 * circleArea) + (circumference * this.height);
        return area;
    }

    public double getRadius() {
        return this.radius;
    }

    public double getHeight() {
        return this.height;
    }

    public void setHeight(double h) {
        this.height = h;
    }

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

    @Override
    public String toString() {
        return this.shape + this.radius + this.height + this.volume + this.area;

    }

    public static void main(String[] args) {
        Cylinder cylinder1 = new Cylinder(1, 17);
        Cylinder cylinder2 = new Cylinder(3, 8);
        Cylinder cylinder3 = new Cylinder(2, 12);
        Cylinder cylinder4 = new Cylinder(1, 14);
    }
}

---

我不知道您是否需要外部类，但如果您只是将main方法放在它为我编译的圆柱体类中

public class Cylinder {
    private double radius = 0.0;
    private double height = 0.0;
    private double area = 0.0;
    private double volume = 0.0;
    private String shape = "cylinder";

    public Cylinder(double r, double h) {
        this.radius = r;
        System.out.print(r);
        this.height = h;
        System.out.print(h);

    }

    public double getVolume() {
        double volume = 3.14 * radius * radius * height;
        return volume;
    }

    public double getArea() {
        double circumference = 3.14 * 2 * radius;
        double circleArea = 3.14 * radius * radius;
        double area = (2 * circleArea) + (circumference * this.height);
        return area;
    }

    public double getRadius() {
        return this.radius;
    }

    public double getHeight() {
        return this.height;
    }

    public void setHeight(double h) {
        this.height = h;
    }

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

    @Override
    public String toString() {
        return this.shape + this.radius + this.height + this.volume + this.area;

    }

    public static void main(String[] args) {
        Cylinder cylinder1 = new Cylinder(1, 17);
        Cylinder cylinder2 = new Cylinder(3, 8);
        Cylinder cylinder3 = new Cylinder(2, 12);
        Cylinder cylinder4 = new Cylinder(1, 14);
    }
}

---

内部类与任何其他成员一样（除了

enum

s）。如果没有显式地将它们声明为静态的，那么它们就不会是静态的，因此您将无法从静态上下文（例如

main

）中访问它们。长话短说-将您的

圆柱体

内部类声明为

静态

，您应该可以：

public class Miller_A03Q1 {

    public static void main(String[] args) {
        Cylinder cylinder1 = new Cylinder(1,17);
        Cylinder cylinder2 = new Cylinder(3,8);
        Cylinder cylinder3 = new Cylinder(2,12);
        Cylinder cylinder4 = new Cylinder (1,14);
    }

    public static class Cylinder{
        // etc...

---

内部类与任何其他成员一样（除了

enum

s）。如果没有显式地将它们声明为静态的，那么它们就不会是静态的，因此您将无法从静态上下文（例如

main

）中访问它们。长话短说-将您的

圆柱体

内部类声明为

静态

，您应该可以：

public class Miller_A03Q1 {

    public static void main(String[] args) {
        Cylinder cylinder1 = new Cylinder(1,17);
        Cylinder cylinder2 = new Cylinder(3,8);
        Cylinder cylinder3 = new Cylinder(2,12);
        Cylinder cylinder4 = new Cylinder (1,14);
    }

    public static class Cylinder{
        // etc...

---

尝试

公共静态类圆柱体{

…您定义的

圆柱体

需要一个

Miller\u A03Q1

的实例。您还可以将

Miller\u A03Q1

和

圆柱体

创建为两个独立的类。尝试

公共静态类圆柱体{

…你定义的

圆柱体

需要一个

Miller\u A03Q1

的实例。你也可以创建

Miller\u A03Q1

和

圆柱体

作为两个独立的类。我不认识你，但我爱你。我不能相信有一个词会让我如此悲伤。@rkstm这在你编写代码时是很正常的。小的错误是最大的麻烦：我不认识你，但我爱你。我不敢相信一个字会让我如此悲伤。@rkstm这在你写代码时是很正常的。小错误是最大的麻烦：D