Java 将两个日期的时间段按照一定天数进行周期切割

 上代码：

    public  static List<CycleTimeVo> getCycleList(int cycleNum,String startTime,String endTime) throws ParseException {
        System.out.println("统计的时间段为：从"+startTime+"到"+endTime);
        Date endParse = new SimpleDateFormat("yyyy-MM-dd").parse(endTime);
        Long endLong = endParse.getTime();

        SimpleDateFormat sdf=new SimpleDateFormat("yyyy-MM-dd");//这个是你要转成后的时间的格式
        endTime = sdf.format(new Date(endLong));
        System.out.println("结束时间是："+endTime);

        int daysBetweenNum = daysBetween(startTime, endTime);
        int cycleForNum = daysBetweenNum % cycleNum == 0 ? (daysBetweenNum / cycleNum) : (daysBetweenNum / cycleNum) + 1;
        System.out.println("两日期间相隔的天数为：" + daysBetweenNum);
        System.out.println("周期选择是：" + cycleNum + "天一周期, 则切割出来的周期存在个数：" + cycleForNum);
        Date startParse = new SimpleDateFormat("yyyy-MM-dd").parse(startTime);
        Long startLong = startParse.getTime();

        Long calculationLong = startLong;

        List<CycleTimeVo> CycleTimeList=new ArrayList();
        for (int i = 1; i <= cycleForNum; i++) {

            String startStr = sdf.format(new Date(calculationLong));
            Date startStrParse = new SimpleDateFormat("yyyy-MM-dd").parse(startStr);
            Long startStrLong = startStrParse.getTime();
            Long cycleLong = cycleNum*86400000l;
            calculationLong = startStrLong + cycleLong;
            String endStr = endTime;
            if (calculationLong <= endLong) {
                endStr = sdf.format(new Date(calculationLong));
            }
            System.out.println("起始:" + startStr + "结束：" + endStr);
            CycleTimeVo cycleTimeVo=new CycleTimeVo();
            cycleTimeVo.setStartTimeStr(startStr);
            cycleTimeVo.setEndTimeStr(endStr);
            CycleTimeList.add(cycleTimeVo);
        }
        System.out.println("周期list："+CycleTimeList.toString());
        return CycleTimeList;
    }

    public static int daysBetween(String smdate, String bdate) throws ParseException {

        SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd");
        Calendar cal = Calendar.getInstance();
        cal.setTime(sdf.parse(smdate));
        long time1 = cal.getTimeInMillis();
        cal.setTime(sdf.parse(bdate));
        long time2 = cal.getTimeInMillis();
        long between_days = (time2 - time1) / (1000 * 3600 * 24);
        return Integer.parseInt(String.valueOf(between_days));

    }

测试结果：

第一个参数为周期的天数，这里示例为7天一个周期切割，

  getCycleList(7,"2020-02-01","2020-02-14");

可以看到结果正确：