概率随机奖品

for (int j = 0; j < 100; j++) {

            List<Prize> prizes = prizeManager.findAll();

            double randomNumber;
            randomNumber = Math.random();

            for (int i = 0; i < prizes.size(); i++) {
                float start = 0;
                float end = 0;
                if(i==0){
                    start = 0;
                    end = (end + prizes.get(i).getWinningRate());
                }
                for (int k = 0; k < i; k++) {
                    start += prizes.get(k).getWinningRate();
                    end = (start+ prizes.get(k+1).getWinningRate());
                }
                double st = start / 100;
                double en = end / 100;
                /*System.out.println(randomNumber >= st );
                System.out.println(randomNumber <= en );*/
                if (randomNumber >= st && randomNumber <= en ) {
                    System.out.println(prizes.get(i).getPrizeName());
//                    return prizes.get(i).getPrizeName();
                }
                }
            }