code: public static int nextInt(Random random) {
  		int n = random.nextInt();
  		if (n == Integer.MIN_VALUE) {
  			n = 0; // corner case
  		} else {
  			n = Math.abs(n);
  		}
  
  		return n;
  	}
docs: 返回0到Intger.MAX_VALUE的随机Int, 可传入ThreadLocalRandom或SecureRandom