抽奖权重工具

工作中近期涉及到了抽奖,总结了一个小的权重抽奖工具,分享给大家

/**
 * @author hman
 * @createTime 2018/7/11
 * @description 按照权重自动抽奖并且返回权重
 */
public class WeightUtil {


    /**
     * @param weights 权重集合 1,2,3,4  ->[1,3,6,10]
     * @return random in [1,3,6,10] by weight
     */
    public static Optional<Integer> randomCoupons(Collection<Integer> weights) {
        if (CollectionUtils.isNotEmpty(weights)) {
            ArrayList<Integer> objects = Lists.newArrayList();
            weights.forEach(t -> objects.add(t));
            Collections.sort(objects);
            Random random = new Random();
            int i = random.nextInt(objects.get(objects.size() - 1) - 1);
            return objects.stream().filter(t -> i <= t).findFirst();
        }
        return Optional.empty();

    }
}