最后是基于
CalendarAPI 的解决方案：
public enum Holidays { FRANCE { @Override protected void addFixedHolidays(Set<Holiday> holidays) { holidays.add(new Holiday(Calendar.JANUARY, 1)); holidays.add(new Holiday(Calendar.MAY, 1)); holidays.add(new Holiday(Calendar.MAY, 8)); holidays.add(new Holiday(Calendar.JULY, 14)); holidays.add(new Holiday(Calendar.AUGUST, 15)); holidays.add(new Holiday(Calendar.NOVEMBER, 1)); holidays.add(new Holiday(Calendar.NOVEMBER, 11)); holidays.add(new Holiday(Calendar.DECEMBER, 25)); } @Override protected void addVariableHolidays(int year, Set<Holiday> holidays) { Date easterSunday = getEasterSunday(year); holidays.add(new Holiday(getEasterMonday(easterSunday))); holidays.add(new Holiday(getAscensionThursday(easterSunday))); holidays.add(new Holiday(getPentecostMonday(easterSunday))); } }, ENGLAND { @Override protected void addFixedHolidays(Set<Holiday> holidays) { holidays.add(new Holiday(Calendar.JANUARY, 1)); holidays.add(new Holiday(Calendar.DECEMBER, 25)); holidays.add(new Holiday(Calendar.DECEMBER, 26)); } @Override protected void addVariableHolidays(int year, Set<Holiday> holidays) { Date easterSunday = getEasterSunday(year); holidays.add(new Holiday(getGoodFriday(easterSunday))); holidays.add(new Holiday(getEasterMonday(easterSunday))); holidays.add(new Holiday(get(WeekdayIndex.FIRST, Calendar.MONDAY, Calendar.MAY, year))); holidays.add(new Holiday(get(WeekdayIndex.LAST, Calendar.MONDAY, Calendar.MAY, year))); holidays.add(new Holiday(get(WeekdayIndex.LAST, Calendar.MONDAY, Calendar.AUGUST, year))); Holiday christmasDay = new Holiday(Calendar.DECEMBER, 25); if (christmasDay.isWeekend(year)) { holidays.add(new Holiday(Calendar.DECEMBER, 27)); } Holiday boxingDay = new Holiday(Calendar.DECEMBER, 26); if (boxingDay.isWeekend(year)) { holidays.add(new Holiday(Calendar.DECEMBER, 28)); } } }; public class HolidayException extends Exception { private static final long serialVersionUID = 1L; private HolidayException(String message) { super(message); } } private class Holiday { private final int day; private final int month; public Holiday(Date date) { Calendar calendar = Calendar.getInstance(); calendar.setTime(date); month = calendar.get(Calendar.MONTH); day = calendar.get(Calendar.DAY_OF_MONTH); } public Holiday(int month, int day) { this.month = month; this.day = day; } public Date toDate(int year) { Calendar calendar = Calendar.getInstance(); calendar.set(year, month, day); return calendar.getTime(); } public boolean isWeekend(int year) { Calendar calendar = Calendar.getInstance(); calendar.setTime(toDate(year)); int dayOfWeek = calendar.get(Calendar.DAY_OF_WEEK); return dayOfWeek == Calendar.SATURDAY || dayOfWeek == Calendar.SUNDAY; } @Override public boolean equals(Object obj) { if (this == obj) { return true; } else if (!(obj instanceof Holiday)) { return false; } else { Holiday holiday = (Holiday) obj; return holiday.month == month && holiday.day == day; } } @Override public int hashCode() { return Arrays.hashCode(new int[] { month, day }); } } public enum WeekdayIndex { FIRST(1), SECOND(2), THIRD(3), FOURTH(4), LAST(null); private final Integer index; private WeekdayIndex(Integer index) { this.index = index; } private boolean is(int count) { return index != null && index == count; } } private final Set<Holiday> fixedHolidays = new HashSet<Holiday>(); private final Map<Integer, Set<Holiday>> variableHolidays = new HashMap<Integer, Set<Holiday>>(); private Holidays() { addFixedHolidays(fixedHolidays); } protected abstract void addFixedHolidays(Set<Holiday> holidays); protected abstract void addVariableHolidays(int year, Set<Holiday> holidays); public int getBusinessDayCount(Date d1, Date d2) throws HolidayException { Calendar calendar = Calendar.getInstance(); DateFormat formatter = new SimpleDateFormat("yyyy-MM-dd"); try { d1 = formatter.parse(formatter.format(d1)); d2 = formatter.parse(formatter.format(d2)); } catch (ParseException ignore) { // cannot happen } if (!isBusinessDay(d1) || !isBusinessDay(d2)) { throw new HolidayException("Input dates must be business days"); } int businessDayCount = 0; Date min = d1.before(d2) ? d1 : d2; Date max = min.equals(d2) ? d1 : d2; calendar.setTime(min); while (calendar.getTime().before(max)) { calendar.add(Calendar.DAY_OF_MONTH, 1); if (isBusinessDay(calendar.getTime())) { businessDayCount++; } } return businessDayCount; } public boolean isBusinessDay(Date date) { Calendar calendar = Calendar.getInstance(); calendar.setTime(date); int dayOfWeek = calendar.get(Calendar.DAY_OF_WEEK); if (dayOfWeek == Calendar.SATURDAY || dayOfWeek == Calendar.SUNDAY) { return false; } else if (isFixedHoliday(date)) { return false; } else if (isVariableHoliday(date)) { return false; } return true; } private boolean isFixedHoliday(Date date) { return fixedHolidays.contains(new Holiday(date)); } private boolean isVariableHoliday(Date date) { Calendar calendar = Calendar.getInstance(); calendar.setTime(date); int year = calendar.get(Calendar.YEAR); Set<Holiday> yearHolidays; if (!variableHolidays.containsKey(year)) { // variable holidays have not been calculated for this year yet yearHolidays = new HashSet<Holiday>(); addVariableHolidays(year, yearHolidays); variableHolidays.put(year, yearHolidays); } else { yearHolidays = variableHolidays.get(year); } return yearHolidays.contains(new Holiday(date)); } public static Date getEasterSunday(int year) { // credits: https://www.wikiwand.com/en/Computus#/Anonymous_Gregorian_algorithm Calendar calendar = Calendar.getInstance(); int initialYear = year; if (year < 1900) { year += 1900; } int a = year % 19; int b = year / 100; int c = year % 100; int d = b / 4; int e = b % 4; int f = (b + 8) / 25; int g = (b - f + 1) / 3; int h = (19 * a + b - d - g + 15) % 30; int i = c / 4; int j = c % 4; int k = (32 + 2 * e + 2 * i - h - j) % 7; int l = (a + 11 * h + 22 * k) / 451; int m = (h + k - 7 * l + 114) % 31; int month = (h + k - 7 * l + 114) / 31 - 1; int day = m + 1; calendar.set(initialYear, month, day); return calendar.getTime(); } public static Date getGoodFriday(Date easterSunday) { Calendar calendar = Calendar.getInstance(); calendar.setTime(easterSunday); calendar.add(Calendar.DAY_OF_MONTH, -2); return calendar.getTime(); } public static Date getEasterMonday(Date easterSunday) { Calendar calendar = Calendar.getInstance(); calendar.setTime(easterSunday); calendar.add(Calendar.DAY_OF_MONTH, 1); return calendar.getTime(); } public static Date getAscensionThursday(Date easterSunday) { Calendar calendar = Calendar.getInstance(); calendar.setTime(easterSunday); calendar.add(Calendar.DAY_OF_MONTH, 39); return calendar.getTime(); } public static Date getPentecostMonday(Date easterSunday) { Calendar calendar = Calendar.getInstance(); calendar.setTime(easterSunday); calendar.add(Calendar.DAY_OF_MONTH, 50); return calendar.getTime(); } public static Date get(WeekdayIndex weekdayIndex, int dayOfWeek, int month, int year) { Calendar calendar = Calendar.getInstance(); calendar.set(year, month, 1); int count = 0; Date last = null; do { if (calendar.get(Calendar.DAY_OF_WEEK) == dayOfWeek) { count++; last = calendar.getTime(); if (weekdayIndex.is(count)) { return last; } } calendar.add(Calendar.DAY_OF_MONTH, 1); } while (calendar.get(Calendar.MONTH) == month); if (weekdayIndex.equals(WeekdayIndex.LAST)) { return last; } return null; }}致电：
Holidays.FRANCE.getBusinessDayCount(d1, d2);
