Erhältlich am nächsten Werktag nach dem angegebenen Datum bei JAVA

import java.text.ParseException;
import java.text.SimpleDateFormat;
import java.util.ArrayList;
import java.util.Calendar;
import java.util.Date;
import java.util.HashMap;
import java.util.List;

public class GetFirstWorkDate {

	public static void main(String[] args) {
		SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd");
		// holiday List for test
		List<String> holidayList = new ArrayList<String>();
		holidayList.add("2019-10-13");
		holidayList.add("2019-10-14");
		holidayList.add("2019-10-15");
		// holidayList.add("2019-10-16");
		// holidayList.add("2019-10-17");
		holidayList.add("2019-10-21");

		// start date
		String date = "2019-10-07";
		// first work day
		Date scheduleActiveDate;
		try {
			scheduleActiveDate = getFirstWorkDate(holidayList, date);
			System.out.println("first work day:" + sdf.format(scheduleActiveDate));
		} catch (ParseException e) {
			e.printStackTrace();
		}
	}

	public static Date getFirstWorkDate(List<String> list, String date) throws ParseException {
		SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd");
		// init start date
		Date currentDate = sdf.parse(date);
		Date nextDate;
		boolean delayFlg = false;

		HashMap<String, Object> map = new HashMap<String, Object>();
		map.put("date", currentDate);
		map.put("delayFlg", delayFlg);

		// get the next work day
		HashMap<String, Object> nextMap = getNextWorkDay(list, map);
		// compare the next work day with start date,if they are the same
		// day,then stop loop and return
		while (!(((Date) map.get("date")).compareTo(((Date) nextMap.get("date"))) == 0)
				|| ((((Date) map.get("date")).compareTo(((Date) nextMap.get("date"))) == 0
						&& (boolean) nextMap.get("delayFlg")))) {
			// reset the start date
			nextDate = (Date) nextMap.get("date");
			currentDate = (Date) map.get("date");
			delayFlg = (boolean) nextMap.get("delayFlg");
			if (currentDate.compareTo(nextDate) == 0 && delayFlg) {
				nextDate = getTargetDaysLater(nextDate, 1);
				delayFlg = false;
			}
			map.put("date", nextDate);
			map.put("delayFlg", delayFlg);
			// get the next work day
			nextMap = getNextWorkDay(list, map);
		}
		return (Date) nextMap.get("date");
	}

	public static HashMap<String, Object> getNextWorkDay(List<String> list, HashMap<String, Object> map)
			throws ParseException {
		SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd");
		HashMap<String, Object> mapTmp = new HashMap<String, Object>();
		Date date = (Date) map.get("date");
		boolean delayFlg = (boolean) map.get("delayFlg");
		Calendar calendar = getCalendar(date);
		if (calendar.get(Calendar.DAY_OF_WEEK) == Calendar.SUNDAY) {
			if (isHoliday(sdf.format(date), list)) {
				delayFlg = true;
			}
			date = getTargetDaysLater(date, 1);

		} else if (calendar.get(Calendar.DAY_OF_WEEK) == Calendar.MONDAY
				|| calendar.get(Calendar.DAY_OF_WEEK) == Calendar.TUESDAY
				|| calendar.get(Calendar.DAY_OF_WEEK) == Calendar.WEDNESDAY
				|| calendar.get(Calendar.DAY_OF_WEEK) == Calendar.THURSDAY) {
			if (isHoliday(sdf.format(date), list)) {
				date = getTargetDaysLater(date, 1);
			}
		} else if (calendar.get(Calendar.DAY_OF_WEEK) == Calendar.FRIDAY) {
			if (isHoliday(sdf.format(date), list)) {
				date = getTargetDaysLater(date, 1);
			}

		} else {
			date = getTargetDaysLater(date, 1);
		}
		// System.out.println("getNextDay:" + sdf.format(date));

		mapTmp.put("date", date);
		mapTmp.put("delayFlg", delayFlg);
		return mapTmp;
	}

	/**
	 * get the delayed date with given days
	 * 
	 * @param Date
	 *            start date
	 * @param int
	 *            delay days
	 * @return
	 */
	public static Date getTargetDaysLater(Date date, int n) {
		Calendar calendar = Calendar.getInstance();
		calendar.setTime(date);
		calendar.add(Calendar.DAY_OF_MONTH, +n);
		date = calendar.getTime();
		return date;
	}

	/**
	 *
	 * @param date
	 * @return Calendar
	 * @throws ParseException
	 */
	public static Calendar getCalendar(Date date) throws ParseException {
		Calendar cal = Calendar.getInstance();
		cal.setTime(date);
		return cal;
	}

	/**
	 *
	 * @param sdate
	 * @param list
	 * @return
	 * @throws ParseException
	 */
	public static boolean isHoliday(String sdate, List<String> list) throws ParseException {
		if (list.size() > 0) {
			for (int i = 0; i < list.size(); i++) {
				if (sdate.equals(list.get(i))) {
					return true;
				}
			}
		}
		return false;
	}
}