獲取當前日期最近7天的日期集合

 private static List<String> getLastWeekDate(){
        
        List<String> list = new ArrayList<String>();
        
        SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd");
        Calendar c = Calendar.getInstance();
        String today = sdf.format(c.getTime());
        list.add(today);
        c.add(Calendar.DAY_OF_YEAR, -1);
        String today_plus1 = sdf.format(c.getTime());
        list.add(today_plus1);
        c.add(Calendar.DAY_OF_YEAR, -1);
        String today_plus2 = sdf.format(c.getTime());
        list.add(today_plus2);
        c.add(Calendar.DAY_OF_YEAR, -1);
        String today_plus3 = sdf.format(c.getTime());
        list.add(today_plus3);
        c.add(Calendar.DAY_OF_YEAR, -1);
        String today_plus4 = sdf.format(c.getTime());
        list.add(today_plus4);
        c.add(Calendar.DAY_OF_YEAR, -1);
        String today_plus5 = sdf.format(c.getTime());
        list.add(today_plus5);
        c.add(Calendar.DAY_OF_YEAR, -1);
        String today_plus6 = sdf.format(c.getTime());
        list.add(today_plus6);

        
        return list;
    }

把時間排序一下  大到小的排序或者是小到大的排序

Collections.reverse(時間集合);