JAVA 根据概率生成的随机数

JAVA 生成 有规律概率的 随机数

public class ProbabilityMathRandom {
    /**
     * 0出现的概率为%50
     */
    public static double rate0 = 0.50;
    /**
     * 1出现的概率为%20
     */
    public static double rate1 = 0.20;
    /**
     * 2出现的概率为%15
     */
    public static double rate2 = 0.15;
    /**
     * 3出现的概率为%10
     */
    public static double rate3 = 0.10;
    /**
     * 4出现的概率为%4
     */
    public static double rate4 = 0.04;
    /**
     * 5出现的概率为%1
     */
    public static double rate5 = 0.01;

    /**
     * Math.random()产生一个double型的随机数，判断一下
     *  例如0出现的概率为%50，则介于0到0.50中间的返回0
     *
     * @return int
     */
    private int PercentageRandom() {
        double randomNumber;
        randomNumber = Math.random();
        if (randomNumber >= 0 && randomNumber <= rate0) {
            return 0;
        } else if (randomNumber >= rate0 / 100 && randomNumber <= rate0 + rate1) {
            return 1;
        } else if (randomNumber >= rate0 + rate1
                && randomNumber <= rate0 + rate1 + rate2) {
            return 2;
        } else if (randomNumber >= rate0 + rate1 + rate2
                && randomNumber <= rate0 + rate1 + rate2 + rate3) {
            return 3;
        } else if (randomNumber >= rate0 + rate1 + rate2 + rate3
                && randomNumber <= rate0 + rate1 + rate2 + rate3 + rate4) {
            return 4;
        } else if (randomNumber >= rate0 + rate1 + rate2 + rate3 + rate4
                && randomNumber <= rate0 + rate1 + rate2 + rate3 + rate4
                + rate5) {
            return 5;
        }
        return -1;
    }
    /**
     * 测试主程序
     *
     * @param agrs
     */
    public static void main(String[] agrs) {
        int i = 0;
        ProbabilityMathRandom a = new ProbabilityMathRandom();
        for (i = 0; i <= 100; i++){//打印100个测试概率的准确性
            System.out.println(a.PercentageRandom());
        }
    }
}