java将时间按月分段

java将时间按月分段 返回分段的数组

/**
 * 按照月份分割一段时间
 *
 * @param startTime     开始时间戳(毫秒)
 * @param endTime       结束时间戳(毫秒)
 */
public static List<Long> getIntervalTimeByMonth(Date startTime, Date endTime) {
    List<Long> dateList = new ArrayList<>();
    Calendar calendar = Calendar.getInstance();
    calendar.setTime(startTime);
    dateList.add(calendar.getTimeInMillis());
    while (calendar.getTimeInMillis() < endTime.getTime()) {
        // 当月底
        calendar.add(Calendar.MONTH, 1);
        calendar.set(Calendar.DAY_OF_MONTH, 1);
        calendar.add(Calendar.DATE, -1);
        calendar.set(Calendar.HOUR_OF_DAY, 23);
        calendar.set(Calendar.MINUTE, 59);
        calendar.set(Calendar.SECOND, 59);
        if(calendar.getTimeInMillis() >= endTime.getTime()){
            dateList.add(endTime.getTime());
            break;
        }
        // 下月初
        calendar.add(Calendar.DATE, 1);
        calendar.set(Calendar.HOUR_OF_DAY, 0);
        calendar.set(Calendar.MINUTE, 0);
        calendar.set(Calendar.SECOND, 0);
        dateList.add(calendar.getTimeInMillis());
    }
    return dateList;
}

测试代码：

public static void main(String[] args) throws ParseException {
    SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");
    Date beginDate = sdf.parse("2021-06-15");
    Date endDate = sdf.parse("2022-06-15");
    List<Long> endDateList = getIntervalTimeByMonth(beginDate, endDate);
    for (int i = 0; i < endDateList.size(); i++) {
        Long beginStr = endDateList.get(i);
        String begin1 = sdf1.format(new Date(beginStr));
        System.out.println("第" + i + "段时间区间:" + begin1);
    }
}

参考
https://www.zhangshengrong.com/p/LKa40OkZaQ/