年会现场抽奖代码到底该怎么写？过来人告诉你答案

/**
 * 抽奖
 *
 * @author 托尼老师
 * @create 2019-12-27 11:11
 **/
public class LotteryTest {
 /**
     * 抽奖
     *
     * @param originalRates 原始的概率列表
     * @return 物品的索引
     */
    public static int lottery(List<Double> originalRates) {
        if (originalRates == null || originalRates.isEmpty()) {
            return -1;
        }

        int size = originalRates.size();

        double sumRate = 0d;
        for (double rate : originalRates) {
            sumRate += rate;
        }

        List<Double> sortOrignalRates = new ArrayList<>(size);
        Double tempSumRate = 0d;
        for (double rate : originalRates) {
            tempSumRate += rate;
            sortOrignalRates.add(tempSumRate / sumRate);
        }

        // 根据区块值来获取抽取到的物品索引
        double nextDouble = Math.random();
        sortOrignalRates.add(nextDouble);
        Collections.sort(sortOrignalRates);

        return sortOrignalRates.indexOf(nextDouble);
    }
  @Test
    public void testLottery() {
        List<Reward> lotteryList = new ArrayList<>();
        Reward r = new Reward();
        r.setRate(0.03d);
        r.setRewardName("双色球彩票一张");
        lotteryList.add(r);
        r = new Reward();
        r.setRate(0.001d);
        r.setRewardName("mac book");
        lotteryList.add(r);
        r = new Reward();
        r.setRate(0.06d);
        r.setRewardName("没抽中");
        lotteryList.add(r);
        r = new Reward();
        r.setRate(0.001d);
        r.setRewardName("迪拜七日双人豪华游");
        lotteryList.add(r);
        List<Double> originalRates = new ArrayList<>();
        for (Reward e : lotteryList) {
            originalRates.add(e.getRate());
        }
        for (int i = 0; i < 20; i++) {
            System.out.println("恭喜抽中========>"
                + lotteryList.get(lottery(originalRates)).getRewardName());
        }
    }
        class Reward {
        //奖品名称
        private String rewardName;
        //概率
        private Double rate;

        public String getRewardName() {
            return rewardName;
        }
        public void setRewardName(String rewardName) {
            this.rewardName = rewardName;
        }
        public Double getRate() {
            return rate;
        }
        public void setRate(Double rate) {
            this.rate = rate;
        }
    }
}