日期转换：年、季度、月份

Calendar

本代码主要是用Calendar类来将起始时间和结束时间这一时间段转换为一年当中的季度。
Calendar:它为特定瞬间与一组诸如 YEAR、MONTH、DAY_OF_MONTH、HOUR 等日历字段之间的转换提供了一些方法，并为操作日历字段（例如获得下星期的日期）提供了一些方法。
常用的方法主要有以下几点：
static Calendar getInstance():由于其构造方法是protected的，所以无法直接创建该对象，通过此方法可以得到Calendar对象。如：Calendar cr=Calendar.getInstance()；。

public void set(int year,int month,int date,int hourofday,int minute,int second):设置日历的年、月、日、时、分、秒。

public int get(int field):返回给定日历字段的值。所谓字段就是年、月、日等等。

public void setTime(Date date):使用给定的Date设置此日历的时间。Date------Calendar。

public Date getTime():返回一个Date表示此日历的时间。Calendar-----Date。

abstract void add(int field,int amount):按照日历的规则，给指定字段添加或减少时间量。

public long getTimeInMillies():以毫秒为单位返回该日历的时间值。

实现

年份

private List<IppcRowNameResponse> getYearBetween(String startTime, String endTime) {

		List<IppcRowNameResponse> monthList = new ArrayList<IppcRowNameResponse>();
		try {

			ArrayList<String> result = new ArrayList<String>();
			SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd");// 格式化为年月

			Calendar min = Calendar.getInstance();
			Calendar max = Calendar.getInstance();

			min.setTime(sdf.parse(startTime));
			min.set(min.get(Calendar.YEAR), min.get(Calendar.MONTH), 1);

			max.setTime(sdf.parse(endTime));
			max.set(max.get(Calendar.YEAR), max.get(Calendar.MONTH), 2);

			Calendar curr = min;
			while (curr.before(max)) {
				result.add(sdf.format(curr.getTime()));
				curr.add(Calendar.MONTH, 1);
			}

			for (String string : result) {
				IppcRowNameResponse monthResponse = new IppcRowNameResponse();
				Date date = sdf.parse(string);
				DateFormat format1 = new SimpleDateFormat("yyyy");
				DateFormat format = new SimpleDateFormat("yyyy年");
				String yearS = format.format(date);
				String year = format1.format(date);

				int intyearMonth = Integer.parseInt(year);
				monthResponse.setId(intyearMonth);
				monthResponse.setMc(yearS);
				monthList.add(monthResponse);
			}
			return monthList;

		} catch (Exception e) {
			e.printStackTrace();
		}
		return monthList;
	}

季度

private static List<IppcRowNameResponse> getQuarterBetween(String startTime, String endTime) {

		List<IppcRowNameResponse> monthList = new ArrayList<IppcRowNameResponse>();
		try {

			ArrayList<String> result = new ArrayList<String>();
			SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd");// 格式化为年月

			Calendar min = Calendar.getInstance();
			Calendar max = Calendar.getInstance();

			min.setTime(sdf.parse(startTime));
			min.set(min.get(Calendar.YEAR), min.get(Calendar.MONTH), 1);

			max.setTime(sdf.parse(endTime));
			max.set(max.get(Calendar.YEAR), max.get(Calendar.MONTH), 2);

			Calendar curr = min;
			while (curr.before(max)) {
				result.add(sdf.format(curr.getTime()));
				curr.add(Calendar.MONTH, 1);
			}

			for (String string : result) {
				IppcRowNameResponse monthResponse = new IppcRowNameResponse();
				Date date = sdf.parse(string);

				DateFormat format1 = new SimpleDateFormat("MM");
				DateFormat format = new SimpleDateFormat("yyyy");
				String year = format.format(date);
				String month = format1.format(date);
				int parseInt = Integer.parseInt(month);
				if (parseInt >= 1 && parseInt <= 3) {
					month = "1";
				} else if (parseInt >= 4 && parseInt <= 6) {
					month = "2";
				} else if (parseInt >= 7 && parseInt <= 9) {
					month = "3";
				} else {
					month = "4";
				}
				int intyearMonth = Integer.parseInt(year + month);
				monthResponse.setId(intyearMonth);
				monthResponse.setMc(year + "年第" + month + "季度");
				monthList.add(monthResponse);
			}
			return monthList;

		} catch (Exception e) {
			e.printStackTrace();
		}
		return monthList;
	}

月份

private List<IppcRowNameResponse> getMonthBetween(String startTime, String endTime) {

		List<IppcRowNameResponse> monthList = new ArrayList<IppcRowNameResponse>();
		try {

			ArrayList<String> result = new ArrayList<String>();
			SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd");// 格式化为年月

			Calendar min = Calendar.getInstance();
			Calendar max = Calendar.getInstance();

			min.setTime(sdf.parse(startTime));
			min.set(min.get(Calendar.YEAR), min.get(Calendar.MONTH), 1);

			max.setTime(sdf.parse(endTime));
			max.set(max.get(Calendar.YEAR), max.get(Calendar.MONTH), 2);

			Calendar curr = min;
			while (curr.before(max)) {
				result.add(sdf.format(curr.getTime()));
				curr.add(Calendar.MONTH, 1);
			}

			for (String string : result) {
				IppcRowNameResponse monthResponse = new IppcRowNameResponse();
				Date date = sdf.parse(string);
				DateFormat format1 = new SimpleDateFormat("yyyyMM");
				DateFormat format = new SimpleDateFormat("yyyy年MM月");
				String month = format.format(date);
				String yearMonth = format1.format(date);
				int intyearMonth = Integer.parseInt(yearMonth);
				monthResponse.setId(intyearMonth);
				monthResponse.setMc(month);
				monthList.add(monthResponse);
			}
			return monthList;

		} catch (Exception e) {
			e.printStackTrace();
		}
		return monthList;
	}

本文地址：https://blog.csdn.net/weixin_45607513/article/details/109643532