隨機生成6位數字，且6個數字不重復

public static int random(){
        int[] array = {0,1,2,3,4,5,6,7,8,9};
        Random rand = new Random();
        for (int i = 10; i > 1; i--) {
            int index = rand.nextInt(i);
            int tmp = array[index];
            array[index] = array[i - 1];
            array[i - 1] = tmp;
        }
        int result = 0;
        for(int i = 0; i < 6; i++)
            result = result * 10 + array[i];
        return result;
    }