必须实现继承的抽象方法错误

Question

我遇到了sphere.java的错误，

The type sphere must implement the inherited abstract method GeometricObjects.hit(Ray)

虽然我看不到我如何获得此错误，因为我定义了命中方法，如下所示。

以下是sphere.java代码：

package Objects;
import Utility.*;

public class Sphere extends GeometricObjects {

    Point3d center;
    double radius;

    public Sphere(Point3d center, double radius, Color color) {
        this.center = new Point3d(center);
        this.radius = radius;
        this.color = new Color(color);
    }

    public double hit(Ray ray) {
        double a = ray.direction.dot(ray.direction);
        double b = 2*ray.origin.sub(center).dot(ray.direction);
        double c = ray.origin.sub(center).dot(ray.origin.sub(center)) - radius*radius;

        double discriminant = b*b - 4*a*c;

        if (discriminant < 0.0){
            return 0.0;
        }
        else {
            double t = (-b - Math.sqrt(discriminant)) / (2*a);

            if (t > 10E-9) {
                return t;
            }
            else {
                return 0.0;
            }
        }
    }
}

这是geomegobobjects.java代码：

package Objects;
import Utility.*;

public abstract class GeometricObjects {
    public Color color;

    public abstract double hit(Ray ray);
}

和Heres ray.java代码>代码：

package Utility;

public class Ray {
    public Point3d origin;
    public Vector direction;

    public Ray(Point3d origin, Vector direction) {
        this.origin = new Point3d(origin);
        this.direction = new Vector(direction);
    }
}