在java中生成随机静态最终数字

Question

我正在为我的学校制作一个游戏，我不能这样做一个静态的最终int获得一个随机数，游戏是小行星，小行星是用多边形制作的，我可以用这样改变多边形的点：

private static final int NUMBER_OF_POINTS = 5;

如果我放

private static final int NUMBER_OF_POINTS = 3;

它创建了一个三角形，但我想在游戏开始时通过生成随机数来生成随机数：

private static final int NUMBER_OF_POINTS = 3;

这是我所做的，但它不起作用：

private static final int NUMBER_OF_POINTS = 3 + (int)(Math.random() * (5 - 3) + 1));

这是整个代码：

/*
 * To change this license header, choose License Headers in Project Properties.
 * To change this template file, choose Tools | Templates
 * and open the template in the editor.
 */
package game;

import java.awt.Polygon;
import java.util.Random;


public enum AsteroidSize {

    /**
     * Small Asteroids have a radius of 15, and are worth 150 points.
     */
    XtraSmall(5.0, 150),
    /**
     * Small Asteroids have a radius of 15, and are worth 100 points.
     */
    Small(15.0, 100),

    /**
     * Medium asteroids have a radius of 25, and are worth 50 points.
     */
    Medium(25.0, 50),

    /**
     * Large asteroids have a radius of 40, and are worth 20 points.
     */
    Large(40.0, 20),
        /**
     * XtraLarge asteroids have a radius of 40, and are worth 10 points.
     */
        XtraLarge(50.0, 10);

    /**
     * The number of points on the Asteroid.
     */
    private static final int NUMBER_OF_POINTS = 5;

    /**
     * The polygon for this type of Asteroid.
     */
    public final Polygon polygon;

    /**
     * The radius of this type of Asteroid.
     */
    public final double radius;

    /**
     * The number of points earned for killing this type of Asteroid.
     */
    public final int killValue;

    /**
     * Creates a new type of Asteroid.
     * @param radius The radius.
     * @param value The kill value.
     */
    private AsteroidSize(double radius, int value) {
        this.polygon = generatePolygon(radius);
        this.radius = radius + 1.0;
        this.killValue = value;
    }

    /**
     * Generates a regular polygon of size radius.
     * @param radius The radius of the Polygon.
     * @return The generated Polygon.
     */
    private static Polygon generatePolygon(double radius) {
        //Create an array to store the coordinates.
        int[] x = new int[NUMBER_OF_POINTS];
        int[] y = new int[NUMBER_OF_POINTS];

        //Generate the points in the polygon.
        double angle = (2 * Math.PI / NUMBER_OF_POINTS);
        for(int i = 0; i < NUMBER_OF_POINTS; i++) {
            x[i] = (int) (radius * Math.sin(i * angle));
            y[i] = (int) (radius * Math.cos(i * angle));
        }

        //Create a new polygon from the generated points and return it.
        return new Polygon(x, y, NUMBER_OF_POINTS);
    }

}