集合中隨機取出幾個資料

if(list.size() > 6) { Random randomId = new Random();

        List<Integer> indexes = new ArrayList<Integer>();
        while(indexes.size() < 6) {
            int index = randomId.nextInt(list.size());
            if(!indexes.contains(index)) {
                indexes.add(index);
            }
        }
        Collections.sort(indexes);
        List<ListObject> newList = new ArrayList<ListObject>();
        for(int index : indexes) {
            newList.add(list.get(index));
        }
        list.clear();
        list.addAll(newList);
    }複製程式碼