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();
}
}
}