java何如通过集合添加00：00到24:00.每半个小时增加一个元素

 @Test
    public void test(){
        List<Date> list = new ArrayList<>();
        Calendar calendar = Calendar.getInstance();

        int index = 1;
        while (index < 24){
            calendar.set(01,1,1,index,0,0);
            Date d = calendar.getTime();
            calendar.add(Calendar.MINUTE,30);
            Date d30 = calendar.getTime();
            list.add(d);
            list.add(d30);
            index++;
        }

        String result = "";
        SimpleDateFormat myFmt = new SimpleDateFormat("HH:mm");
        for (Date d: list) {
            result = result + myFmt.format(d) + "\n";
        }

        assert list.size() == 46;
    }