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	/*
	* Copyright (c) 2003, 2011, Oracle and/or its affiliates. All rights reserved.
	* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
	*
	* This code is free software; you can redistribute it and/or modify it
	* under the terms of the GNU General Public License version 2 only, as
	* published by the Free Software Foundation. Oracle designates this
	* particular file as subject to the "Classpath" exception as provided
	* by Oracle in the LICENSE file that accompanied this code.
	*
	* This code is distributed in the hope that it will be useful, but WITHOUT
	* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
	* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
	* version 2 for more details (a copy is included in the LICENSE file that
	* accompanied this code).
	*
	* You should have received a copy of the GNU General Public License version
	* 2 along with this work; if not, write to the Free Software Foundation,
	* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
	*
	* Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
	* or visit www.oracle.com if you need additional information or have any
	* questions.
	*/

	package sun.util.calendar;

	import java.util.TimeZone;

	/**
	* The {@code BaseCalendar} provides basic calendar calculation
	* functions to support the Julian, Gregorian, and Gregorian-based
	* calendar systems.
	*
	* @author Masayoshi Okutsu
	* @since 1.5
	*/

	public abstract class BaseCalendar extends AbstractCalendar {

	public static final int JANUARY = 1;
	public static final int FEBRUARY = 2;
	public static final int MARCH = 3;
	public static final int APRIL = 4;
	public static final int MAY = 5;
	public static final int JUNE = 6;
	public static final int JULY = 7;
	public static final int AUGUST = 8;
	public static final int SEPTEMBER = 9;
	public static final int OCTOBER = 10;
	public static final int NOVEMBER = 11;
	public static final int DECEMBER = 12;

	// day of week constants
	public static final int SUNDAY = 1;
	public static final int MONDAY = 2;
	public static final int TUESDAY = 3;
	public static final int WEDNESDAY = 4;
	public static final int THURSDAY = 5;
	public static final int FRIDAY = 6;
	public static final int SATURDAY = 7;

	// The base Gregorian year of FIXED_DATES[]
	private static final int BASE_YEAR = 1970;

	// Pre-calculated fixed dates of January 1 from BASE_YEAR
	// (Gregorian). This table covers all the years that can be
	// supported by the POSIX time_t (32-bit) after the Epoch. Note
	// that the data type is int[].
	private static final int[] FIXED_DATES = {
	719163, // 1970
	719528, // 1971
	719893, // 1972
	720259, // 1973
	720624, // 1974
	720989, // 1975
	721354, // 1976
	721720, // 1977
	722085, // 1978
	722450, // 1979
	722815, // 1980
	723181, // 1981
	723546, // 1982
	723911, // 1983
	724276, // 1984
	724642, // 1985
	725007, // 1986
	725372, // 1987
	725737, // 1988
	726103, // 1989
	726468, // 1990
	726833, // 1991
	727198, // 1992
	727564, // 1993
	727929, // 1994
	728294, // 1995
	728659, // 1996
	729025, // 1997
	729390, // 1998
	729755, // 1999
	730120, // 2000
	730486, // 2001
	730851, // 2002
	731216, // 2003
	731581, // 2004
	731947, // 2005
	732312, // 2006
	732677, // 2007
	733042, // 2008
	733408, // 2009
	733773, // 2010
	734138, // 2011
	734503, // 2012
	734869, // 2013
	735234, // 2014
	735599, // 2015
	735964, // 2016
	736330, // 2017
	736695, // 2018
	737060, // 2019
	737425, // 2020
	737791, // 2021
	738156, // 2022
	738521, // 2023
	738886, // 2024
	739252, // 2025
	739617, // 2026
	739982, // 2027
	740347, // 2028
	740713, // 2029
	741078, // 2030
	741443, // 2031
	741808, // 2032
	742174, // 2033
	742539, // 2034
	742904, // 2035
	743269, // 2036
	743635, // 2037
	744000, // 2038
	744365, // 2039
	};

	public abstract static class Date extends CalendarDate {
	protected Date() {
	super();
	}
	protected Date(TimeZone zone) {
	super(zone);
	}

	public Date setNormalizedDate(int normalizedYear, int month, int dayOfMonth) {
	setNormalizedYear(normalizedYear);
	setMonth(month).setDayOfMonth(dayOfMonth);
	return this;
	}

	public abstract int getNormalizedYear();

	public abstract void setNormalizedYear(int normalizedYear);

	// Cache for the fixed date of January 1 and year length of the
	// cachedYear. A simple benchmark showed 7% performance
	// improvement with >90% cache hit. The initial values are for Gregorian.
	int cachedYear = 2004;
	long cachedFixedDateJan1 = 731581L;
	long cachedFixedDateNextJan1 = cachedFixedDateJan1 + 366;

	protected final boolean hit(int year) {
	return year == cachedYear;
	}

	protected final boolean hit(long fixedDate) {
	return (fixedDate >= cachedFixedDateJan1 &&
	fixedDate < cachedFixedDateNextJan1);
	}
	protected int getCachedYear() {
	return cachedYear;
	}

	protected long getCachedJan1() {
	return cachedFixedDateJan1;
	}

	protected void setCache(int year, long jan1, int len) {
	cachedYear = year;
	cachedFixedDateJan1 = jan1;
	cachedFixedDateNextJan1 = jan1 + len;
	}
	}

	public boolean validate(CalendarDate date) {
	Date bdate = (Date) date;
	if (bdate.isNormalized()) {
	return true;
	}
	int month = bdate.getMonth();
	if (month < JANUARY \|\| month > DECEMBER) {
	return false;
	}
	int d = bdate.getDayOfMonth();
	if (d <= 0 \|\| d > getMonthLength(bdate.getNormalizedYear(), month)) {
	return false;
	}
	int dow = bdate.getDayOfWeek();
	if (dow != Date.FIELD_UNDEFINED && dow != getDayOfWeek(bdate)) {
	return false;
	}

	if (!validateTime(date)) {
	return false;
	}

	bdate.setNormalized(true);
	return true;
	}

	public boolean normalize(CalendarDate date) {
	if (date.isNormalized()) {
	return true;
	}

	Date bdate = (Date) date;
	TimeZone zi = bdate.getZone();

	// If the date has a time zone, then we need to recalculate
	// the calendar fields. Let getTime() do it.
	if (zi != null) {
	getTime(date);
	return true;
	}

	int days = normalizeTime(bdate);
	normalizeMonth(bdate);
	long d = (long)bdate.getDayOfMonth() + days;
	int m = bdate.getMonth();
	int y = bdate.getNormalizedYear();
	int ml = getMonthLength(y, m);

	if (!(d > 0 && d <= ml)) {
	if (d <= 0 && d > -28) {
	ml = getMonthLength(y, --m);
	d += ml;
	bdate.setDayOfMonth((int) d);
	if (m == 0) {
	m = DECEMBER;
	bdate.setNormalizedYear(y - 1);
	}
	bdate.setMonth(m);
	} else if (d > ml && d < (ml + 28)) {
	d -= ml;
	++m;
	bdate.setDayOfMonth((int)d);
	if (m > DECEMBER) {
	bdate.setNormalizedYear(y + 1);
	m = JANUARY;
	}
	bdate.setMonth(m);
	} else {
	long fixedDate = d + getFixedDate(y, m, 1, bdate) - 1L;
	getCalendarDateFromFixedDate(bdate, fixedDate);
	}
	} else {
	bdate.setDayOfWeek(getDayOfWeek(bdate));
	}
	date.setLeapYear(isLeapYear(bdate.getNormalizedYear()));
	date.setZoneOffset(0);
	date.setDaylightSaving(0);
	bdate.setNormalized(true);
	return true;
	}

	void normalizeMonth(CalendarDate date) {
	Date bdate = (Date) date;
	int year = bdate.getNormalizedYear();
	long month = bdate.getMonth();
	if (month <= 0) {
	long xm = 1L - month;
	year -= (int)((xm / 12) + 1);
	month = 13 - (xm % 12);
	bdate.setNormalizedYear(year);
	bdate.setMonth((int) month);
	} else if (month > DECEMBER) {
	year += (int)((month - 1) / 12);
	month = ((month - 1)) % 12 + 1;
	bdate.setNormalizedYear(year);
	bdate.setMonth((int) month);
	}
	}

	/**
	* Returns 366 if the specified date is in a leap year, or 365
	* otherwise This method does not perform the normalization with
	* the specified {@code CalendarDate}. The
	* {@code CalendarDate} must be normalized to get a correct
	* value.
	*
	* @param date a {@code CalendarDate}
	* @return a year length in days
	* @throws ClassCastException if the specified date is not a
	* {@link BaseCalendar.Date}
	*/
	public int getYearLength(CalendarDate date) {
	return isLeapYear(((Date)date).getNormalizedYear()) ? 366 : 365;
	}

	public int getYearLengthInMonths(CalendarDate date) {
	return 12;
	}

	static final int[] DAYS_IN_MONTH
	// 12 1 2 3 4 5 6 7 8 9 10 11 12
	= { 31, 31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31};
	static final int[] ACCUMULATED_DAYS_IN_MONTH
	// 12/1 1/1 2/1 3/1 4/1 5/1 6/1 7/1 8/1 9/1 10/1 11/1 12/1
	= { -30, 0, 31, 59, 90,120,151,181,212,243, 273, 304, 334};

	static final int[] ACCUMULATED_DAYS_IN_MONTH_LEAP
	// 12/1 1/1 2/1 3/1 4/1 5/1 6/1 7/1 8/1 9/1 10/1 11/1 12/1
	= { -30, 0, 31, 59+1, 90+1,120+1,151+1,181+1,212+1,243+1, 273+1, 304+1, 334+1};

	public int getMonthLength(CalendarDate date) {
	Date gdate = (Date) date;
	int month = gdate.getMonth();
	if (month < JANUARY \|\| month > DECEMBER) {
	throw new IllegalArgumentException("Illegal month value: " + month);
	}
	return getMonthLength(gdate.getNormalizedYear(), month);
	}

	// accepts 0 (December in the previous year) to 12.
	private int getMonthLength(int year, int month) {
	int days = DAYS_IN_MONTH[month];
	if (month == FEBRUARY && isLeapYear(year)) {
	days++;
	}
	return days;
	}

	public long getDayOfYear(CalendarDate date) {
	return getDayOfYear(((Date)date).getNormalizedYear(),
	date.getMonth(),
	date.getDayOfMonth());
	}

	final long getDayOfYear(int year, int month, int dayOfMonth) {
	return (long) dayOfMonth
	+ (isLeapYear(year) ?
	ACCUMULATED_DAYS_IN_MONTH_LEAP[month] : ACCUMULATED_DAYS_IN_MONTH[month]);
	}

	// protected
	public long getFixedDate(CalendarDate date) {
	if (!date.isNormalized()) {
	normalizeMonth(date);
	}
	return getFixedDate(((Date)date).getNormalizedYear(),
	date.getMonth(),
	date.getDayOfMonth(),
	(BaseCalendar.Date) date);
	}

	// public for java.util.GregorianCalendar
	public long getFixedDate(int year, int month, int dayOfMonth, BaseCalendar.Date cache) {
	boolean isJan1 = month == JANUARY && dayOfMonth == 1;

	// Look up the one year cache
	if (cache != null && cache.hit(year)) {
	if (isJan1) {
	return cache.getCachedJan1();
	}
	return cache.getCachedJan1() + getDayOfYear(year, month, dayOfMonth) - 1;
	}

	// Look up the pre-calculated fixed date table
	int n = year - BASE_YEAR;
	if (n >= 0 && n < FIXED_DATES.length) {
	long jan1 = FIXED_DATES[n];
	if (cache != null) {
	cache.setCache(year, jan1, isLeapYear(year) ? 366 : 365);
	}
	return isJan1 ? jan1 : jan1 + getDayOfYear(year, month, dayOfMonth) - 1;
	}

	long prevyear = (long)year - 1;
	long days = dayOfMonth;

	if (prevyear >= 0) {
	days += (365 * prevyear)
	+ (prevyear / 4)
	- (prevyear / 100)
	+ (prevyear / 400)
	+ ((367 * month - 362) / 12);
	} else {
	days += (365 * prevyear)
	+ CalendarUtils.floorDivide(prevyear, 4)
	- CalendarUtils.floorDivide(prevyear, 100)
	+ CalendarUtils.floorDivide(prevyear, 400)
	+ CalendarUtils.floorDivide((367 * month - 362), 12);
	}

	if (month > FEBRUARY) {
	days -= isLeapYear(year) ? 1 : 2;
	}

	// If it's January 1, update the cache.
	if (cache != null && isJan1) {
	cache.setCache(year, days, isLeapYear(year) ? 366 : 365);
	}

	return days;
	}

	/**
	* Calculates calendar fields and store them in the specified
	* {@code CalendarDate}.
	*/
	// should be 'protected'
	public void getCalendarDateFromFixedDate(CalendarDate date,
	long fixedDate) {
	Date gdate = (Date) date;
	int year;
	long jan1;
	boolean isLeap;
	if (gdate.hit(fixedDate)) {
	year = gdate.getCachedYear();
	jan1 = gdate.getCachedJan1();
	isLeap = isLeapYear(year);
	} else {
	// Looking up FIXED_DATES[] here didn't improve performance
	// much. So we calculate year and jan1. getFixedDate()
	// will look up FIXED_DATES[] actually.
	year = getGregorianYearFromFixedDate(fixedDate);
	jan1 = getFixedDate(year, JANUARY, 1, null);
	isLeap = isLeapYear(year);
	// Update the cache data
	gdate.setCache (year, jan1, isLeap ? 366 : 365);
	}

	int priorDays = (int)(fixedDate - jan1);
	long mar1 = jan1 + 31 + 28;
	if (isLeap) {
	++mar1;
	}
	if (fixedDate >= mar1) {
	priorDays += isLeap ? 1 : 2;
	}
	int month = 12 * priorDays + 373;
	if (month > 0) {
	month /= 367;
	} else {
	month = CalendarUtils.floorDivide(month, 367);
	}
	long month1 = jan1 + ACCUMULATED_DAYS_IN_MONTH[month];
	if (isLeap && month >= MARCH) {
	++month1;
	}
	int dayOfMonth = (int)(fixedDate - month1) + 1;
	int dayOfWeek = getDayOfWeekFromFixedDate(fixedDate);
	assert dayOfWeek > 0 : "negative day of week " + dayOfWeek;
	gdate.setNormalizedYear(year);
	gdate.setMonth(month);
	gdate.setDayOfMonth(dayOfMonth);
	gdate.setDayOfWeek(dayOfWeek);
	gdate.setLeapYear(isLeap);
	gdate.setNormalized(true);
	}

	/**
	* Returns the day of week of the given Gregorian date.
	*/
	public int getDayOfWeek(CalendarDate date) {
	long fixedDate = getFixedDate(date);
	return getDayOfWeekFromFixedDate(fixedDate);
	}

	public static final int getDayOfWeekFromFixedDate(long fixedDate) {
	// The fixed day 1 (January 1, 1 Gregorian) is Monday.
	if (fixedDate >= 0) {
	return (int)(fixedDate % 7) + SUNDAY;
	}
	return (int)CalendarUtils.mod(fixedDate, 7) + SUNDAY;
	}

	public int getYearFromFixedDate(long fixedDate) {
	return getGregorianYearFromFixedDate(fixedDate);
	}

	/**
	* Returns the Gregorian year number of the given fixed date.
	*/
	final int getGregorianYearFromFixedDate(long fixedDate) {
	long d0;
	int d1, d2, d3, d4;
	int n400, n100, n4, n1;
	int year;

	if (fixedDate > 0) {
	d0 = fixedDate - 1;
	n400 = (int)(d0 / 146097);
	d1 = (int)(d0 % 146097);
	n100 = d1 / 36524;
	d2 = d1 % 36524;
	n4 = d2 / 1461;
	d3 = d2 % 1461;
	n1 = d3 / 365;
	d4 = (d3 % 365) + 1;
	} else {
	d0 = fixedDate - 1;
	n400 = (int)CalendarUtils.floorDivide(d0, 146097L);
	d1 = (int)CalendarUtils.mod(d0, 146097L);
	n100 = CalendarUtils.floorDivide(d1, 36524);
	d2 = CalendarUtils.mod(d1, 36524);
	n4 = CalendarUtils.floorDivide(d2, 1461);
	d3 = CalendarUtils.mod(d2, 1461);
	n1 = CalendarUtils.floorDivide(d3, 365);
	d4 = CalendarUtils.mod(d3, 365) + 1;
	}
	year = 400 * n400 + 100 * n100 + 4 * n4 + n1;
	if (!(n100 == 4 \|\| n1 == 4)) {
	++year;
	}
	return year;
	}

	/**
	* @return true if the specified year is a Gregorian leap year, or
	* false otherwise.
	* @see BaseCalendar#isGregorianLeapYear
	*/
	protected boolean isLeapYear(CalendarDate date) {
	return isLeapYear(((Date)date).getNormalizedYear());
	}

	boolean isLeapYear(int normalizedYear) {
	return CalendarUtils.isGregorianLeapYear(normalizedYear);
	}
	}

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