-
GregorianCalendar
-
BC: int
-
BCE: int
-
AD: int
-
CE: int
-
EPOCH_OFFSET: int
-
EPOCH_YEAR: int
-
MONTH_LENGTH: int[]
-
LEAP_MONTH_LENGTH: int[]
-
ONE_SECOND: int
-
ONE_MINUTE: int
-
ONE_HOUR: int
-
ONE_DAY: long
-
ONE_WEEK: long
-
MIN_VALUES: int[]
-
LEAST_MAX_VALUES: int[]
-
MAX_VALUES: int[]
-
serialVersionUID: long
-
gcal: Gregorian
-
jcal: JulianCalendar
-
jeras: Era[]
-
DEFAULT_GREGORIAN_CUTOVER: long
-
gregorianCutover: long
-
gregorianCutoverDate: long
-
gregorianCutoverYear: int
-
gregorianCutoverYearJulian: int
-
gdate: Date
-
cdate: Date
-
calsys: BaseCalendar
-
zoneOffsets: int[]
-
originalFields: int[]
-
GregorianCalendar(): void
-
GregorianCalendar(TimeZone): void
-
GregorianCalendar(Locale): void
-
GregorianCalendar(TimeZone, Locale): void
-
GregorianCalendar(int, int, int): void
-
GregorianCalendar(int, int, int, int, int): void
-
GregorianCalendar(int, int, int, int, int, int): void
-
GregorianCalendar(int, int, int, int, int, int, int): void
-
GregorianCalendar(TimeZone, Locale, boolean): void
-
setGregorianChange(Date): void
-
setGregorianChange(long): void
-
getGregorianChange(): Date
-
isLeapYear(int): boolean
-
getCalendarType(): String
-
equals(Object): boolean
-
hashCode(): int
-
add(int, int): void
-
roll(int, boolean): void
-
roll(int, int): void
-
getMinimum(int): int
-
getMaximum(int): int
-
getGreatestMinimum(int): int
-
getLeastMaximum(int): int
-
getActualMinimum(int): int
-
getActualMaximum(int): int
-
getYearOffsetInMillis(): long
-
clone(): Object
-
getTimeZone(): TimeZone
-
setTimeZone(TimeZone): void
-
isWeekDateSupported(): boolean
-
getWeekYear(): int
-
setWeekDate(int, int, int): void
-
getWeeksInWeekYear(): int
-
cachedFixedDate: long
-
computeFields(): void
-
computeFields(int, int): int
-
getWeekNumber(long, long): int
-
computeTime(): void
-
getFixedDate(BaseCalendar, int, int): long
-
getNormalizedCalendar(): GregorianCalendar
-
getJulianCalendarSystem(): BaseCalendar
-
getCutoverCalendarSystem(): BaseCalendar
-
isCutoverYear(int): boolean
-
getFixedDateJan1(Date, long): long
-
getFixedDateMonth1(Date, long): long
-
getCalendarDate(long): Date
-
getGregorianCutoverDate(): Date
-
getLastJulianDate(): Date
-
monthLength(int, int): int
-
monthLength(int): int
-
actualMonthLength(): int
-
yearLength(int): int
-
yearLength(): int
-
pinDayOfMonth(): void
-
getCurrentFixedDate(): long
-
getRolledValue(int, int, int, int): int
-
internalGetEra(): int
-
readObject(ObjectInputStream): void
-
toZonedDateTime(): ZonedDateTime
-
from(ZonedDateTime): GregorianCalendar
-
/*
* Copyright (c) 1996, 2020, 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.
*/
/*
* (C) Copyright Taligent, Inc. 1996-1998 - All Rights Reserved
* (C) Copyright IBM Corp. 1996-1998 - All Rights Reserved
*
* The original version of this source code and documentation is copyrighted
* and owned by Taligent, Inc., a wholly-owned subsidiary of IBM. These
* materials are provided under terms of a License Agreement between Taligent
* and Sun. This technology is protected by multiple US and International
* patents. This notice and attribution to Taligent may not be removed.
* Taligent is a registered trademark of Taligent, Inc.
*
*/
package java.util;
import java.io.IOException;
import java.io.ObjectInputStream;
import java.time.Instant;
import java.time.ZonedDateTime;
import java.time.temporal.ChronoField;
import sun.util.calendar.BaseCalendar;
import sun.util.calendar.CalendarDate;
import sun.util.calendar.CalendarSystem;
import sun.util.calendar.CalendarUtils;
import sun.util.calendar.Era;
import sun.util.calendar.Gregorian;
import sun.util.calendar.JulianCalendar;
import sun.util.calendar.ZoneInfo;
GregorianCalendar is a concrete subclass of Calendar and provides the standard calendar system used by most of the world. GregorianCalendar is a hybrid calendar that supports both the Julian and Gregorian calendar systems with the support of a single discontinuity, which corresponds by default to the Gregorian date when the Gregorian calendar was instituted (October 15, 1582 in some countries, later in others). The cutover date may be changed by the caller by calling setGregorianChange().
Historically, in those countries which adopted the Gregorian calendar first, October 4, 1582 (Julian) was thus followed by October 15, 1582 (Gregorian). This calendar models this correctly. Before the Gregorian cutover, GregorianCalendar implements the Julian calendar. The only difference between the Gregorian and the Julian calendar is the leap year rule. The Julian calendar specifies leap years every four years, whereas the Gregorian calendar omits century years which are not divisible by 400.
GregorianCalendar implements proleptic Gregorian and Julian calendars. That is, dates are computed by extrapolating the current rules indefinitely far backward and forward in time. As a result, GregorianCalendar may be used for all years to generate meaningful and consistent results. However, dates obtained using GregorianCalendar are historically accurate only from March 1, 4 AD onward, when modern Julian calendar rules were adopted. Before this date, leap year rules were applied irregularly, and before 45 BC the Julian calendar did not even exist.
Prior to the institution of the Gregorian calendar, New Year's Day was
March 25. To avoid confusion, this calendar always uses January 1. A manual
adjustment may be made if desired for dates that are prior to the Gregorian
changeover and which fall between January 1 and March 24.
Week Of Year and Week Year
Values calculated for the
WEEK_OF_YEAR field range from 1 to 53. The first week of a calendar year is the earliest seven day period starting on getFirstDayOfWeek() that contains at least
getMinimalDaysInFirstWeek() days from that year. It thus depends on the values of getMinimalDaysInFirstWeek(),
getFirstDayOfWeek(), and the day of the week of January 1. Weeks between week 1 of one year and week 1 of the following year (exclusive) are numbered sequentially from 2 to 52 or 53 (except for year(s) involved in the Julian-Gregorian transition).
The getFirstDayOfWeek() and
getMinimalDaysInFirstWeek() values are initialized using locale-dependent resources when constructing a
GregorianCalendar. The week
determination is compatible with the ISO 8601 standard when
getFirstDayOfWeek() is MONDAY and
getMinimalDaysInFirstWeek() is 4, which values are used in locales where the standard is preferred. These values can explicitly be set by calling setFirstDayOfWeek() and
setMinimalDaysInFirstWeek().
A week year is in sync with a WEEK_OF_YEAR cycle. All weeks between the first and last weeks (inclusive) have the same week year value.
Therefore, the first and last days of a week year may have
different calendar year values.
For example, January 1, 1998 is a Thursday. If
getFirstDayOfWeek() is MONDAY and
getMinimalDaysInFirstWeek() is 4 (ISO 8601 standard compatible setting), then week 1 of 1998 starts on December 29, 1997, and ends on January 4, 1998. The week year is 1998 for the last three days of calendar year 1997. If, however, getFirstDayOfWeek() is SUNDAY, then week 1 of 1998 starts on January 4, 1998, and ends on January 10, 1998; the first three days of 1998 then are part of week 53 of 1997 and their week year is 1997.
Week Of Month
Values calculated for the WEEK_OF_MONTH field range from 0 to 6. Week 1 of a month (the days with WEEK_OF_MONTH =
1) is the earliest set of at least getMinimalDaysInFirstWeek() contiguous days in that month, ending on the day before getFirstDayOfWeek(). Unlike week 1 of a year, week 1 of a month may be shorter than 7 days, need not start on getFirstDayOfWeek(), and will not include days of the previous month. Days of a month before week 1 have a WEEK_OF_MONTH of 0.
For example, if getFirstDayOfWeek() is SUNDAY and getMinimalDaysInFirstWeek() is 4, then the first week of January 1998 is Sunday, January 4 through Saturday, January 10. These days have a WEEK_OF_MONTH of 1. Thursday, January 1 through Saturday, January 3 have a WEEK_OF_MONTH of 0. If getMinimalDaysInFirstWeek() is changed to 3, then January 1 through January 3 have a WEEK_OF_MONTH of 1.
Default Fields Values
The clear method sets calendar field(s) undefined. GregorianCalendar uses the following default value for each calendar field if its value is undefined.
GregorianCalendar default field values
Field
Default Value
ERA
AD
YEAR
1970
MONTH
JANUARY
DAY_OF_MONTH
1
DAY_OF_WEEK
the first day of week
WEEK_OF_MONTH
0
DAY_OF_WEEK_IN_MONTH
1
AM_PM
AM
HOUR, HOUR_OF_DAY, MINUTE, SECOND, MILLISECOND
0
Default values are not applicable for the fields not listed above.
Example:
// get the supported ids for GMT-08:00 (Pacific Standard Time)
String[] ids = TimeZone.getAvailableIDs(-8 * 60 * 60 * 1000);
// if no ids were returned, something is wrong. get out.
if (ids.length == 0)
System.exit(0);
// begin output
System.out.println("Current Time");
// create a Pacific Standard Time time zone
SimpleTimeZone pdt = new SimpleTimeZone(-8 * 60 * 60 * 1000, ids[0]);
// set up rules for Daylight Saving Time
pdt.setStartRule(Calendar.APRIL, 1, Calendar.SUNDAY, 2 * 60 * 60 * 1000);
pdt.setEndRule(Calendar.OCTOBER, -1, Calendar.SUNDAY, 2 * 60 * 60 * 1000);
// create a GregorianCalendar with the Pacific Daylight time zone
// and the current date and time
Calendar calendar = new GregorianCalendar(pdt);
Date trialTime = new Date();
calendar.setTime(trialTime);
// print out a bunch of interesting things
System.out.println("ERA: " + calendar.get(Calendar.ERA));
System.out.println("YEAR: " + calendar.get(Calendar.YEAR));
System.out.println("MONTH: " + calendar.get(Calendar.MONTH));
System.out.println("WEEK_OF_YEAR: " + calendar.get(Calendar.WEEK_OF_YEAR));
System.out.println("WEEK_OF_MONTH: " + calendar.get(Calendar.WEEK_OF_MONTH));
System.out.println("DATE: " + calendar.get(Calendar.DATE));
System.out.println("DAY_OF_MONTH: " + calendar.get(Calendar.DAY_OF_MONTH));
System.out.println("DAY_OF_YEAR: " + calendar.get(Calendar.DAY_OF_YEAR));
System.out.println("DAY_OF_WEEK: " + calendar.get(Calendar.DAY_OF_WEEK));
System.out.println("DAY_OF_WEEK_IN_MONTH: "
+ calendar.get(Calendar.DAY_OF_WEEK_IN_MONTH));
System.out.println("AM_PM: " + calendar.get(Calendar.AM_PM));
System.out.println("HOUR: " + calendar.get(Calendar.HOUR));
System.out.println("HOUR_OF_DAY: " + calendar.get(Calendar.HOUR_OF_DAY));
System.out.println("MINUTE: " + calendar.get(Calendar.MINUTE));
System.out.println("SECOND: " + calendar.get(Calendar.SECOND));
System.out.println("MILLISECOND: " + calendar.get(Calendar.MILLISECOND));
System.out.println("ZONE_OFFSET: "
+ (calendar.get(Calendar.ZONE_OFFSET)/(60*60*1000)));
System.out.println("DST_OFFSET: "
+ (calendar.get(Calendar.DST_OFFSET)/(60*60*1000)));
System.out.println("Current Time, with hour reset to 3");
calendar.clear(Calendar.HOUR_OF_DAY); // so doesn't override
calendar.set(Calendar.HOUR, 3);
System.out.println("ERA: " + calendar.get(Calendar.ERA));
System.out.println("YEAR: " + calendar.get(Calendar.YEAR));
System.out.println("MONTH: " + calendar.get(Calendar.MONTH));
System.out.println("WEEK_OF_YEAR: " + calendar.get(Calendar.WEEK_OF_YEAR));
System.out.println("WEEK_OF_MONTH: " + calendar.get(Calendar.WEEK_OF_MONTH));
System.out.println("DATE: " + calendar.get(Calendar.DATE));
System.out.println("DAY_OF_MONTH: " + calendar.get(Calendar.DAY_OF_MONTH));
System.out.println("DAY_OF_YEAR: " + calendar.get(Calendar.DAY_OF_YEAR));
System.out.println("DAY_OF_WEEK: " + calendar.get(Calendar.DAY_OF_WEEK));
System.out.println("DAY_OF_WEEK_IN_MONTH: "
+ calendar.get(Calendar.DAY_OF_WEEK_IN_MONTH));
System.out.println("AM_PM: " + calendar.get(Calendar.AM_PM));
System.out.println("HOUR: " + calendar.get(Calendar.HOUR));
System.out.println("HOUR_OF_DAY: " + calendar.get(Calendar.HOUR_OF_DAY));
System.out.println("MINUTE: " + calendar.get(Calendar.MINUTE));
System.out.println("SECOND: " + calendar.get(Calendar.SECOND));
System.out.println("MILLISECOND: " + calendar.get(Calendar.MILLISECOND));
System.out.println("ZONE_OFFSET: "
+ (calendar.get(Calendar.ZONE_OFFSET)/(60*60*1000))); // in hours
System.out.println("DST_OFFSET: "
+ (calendar.get(Calendar.DST_OFFSET)/(60*60*1000))); // in hours
Author: David Goldsmith, Mark Davis, Chen-Lieh Huang, Alan Liu See Also: Since: 1.1
/**
* {@code GregorianCalendar} is a concrete subclass of
* {@code Calendar} and provides the standard calendar system
* used by most of the world.
*
* <p> {@code GregorianCalendar} is a hybrid calendar that
* supports both the Julian and Gregorian calendar systems with the
* support of a single discontinuity, which corresponds by default to
* the Gregorian date when the Gregorian calendar was instituted
* (October 15, 1582 in some countries, later in others). The cutover
* date may be changed by the caller by calling {@link
* #setGregorianChange(Date) setGregorianChange()}.
*
* <p>
* Historically, in those countries which adopted the Gregorian calendar first,
* October 4, 1582 (Julian) was thus followed by October 15, 1582 (Gregorian). This calendar models
* this correctly. Before the Gregorian cutover, {@code GregorianCalendar}
* implements the Julian calendar. The only difference between the Gregorian
* and the Julian calendar is the leap year rule. The Julian calendar specifies
* leap years every four years, whereas the Gregorian calendar omits century
* years which are not divisible by 400.
*
* <p>
* {@code GregorianCalendar} implements <em>proleptic</em> Gregorian and
* Julian calendars. That is, dates are computed by extrapolating the current
* rules indefinitely far backward and forward in time. As a result,
* {@code GregorianCalendar} may be used for all years to generate
* meaningful and consistent results. However, dates obtained using
* {@code GregorianCalendar} are historically accurate only from March 1, 4
* AD onward, when modern Julian calendar rules were adopted. Before this date,
* leap year rules were applied irregularly, and before 45 BC the Julian
* calendar did not even exist.
*
* <p>
* Prior to the institution of the Gregorian calendar, New Year's Day was
* March 25. To avoid confusion, this calendar always uses January 1. A manual
* adjustment may be made if desired for dates that are prior to the Gregorian
* changeover and which fall between January 1 and March 24.
*
* <h2><a id="week_and_year">Week Of Year and Week Year</a></h2>
*
* <p>Values calculated for the {@link Calendar#WEEK_OF_YEAR
* WEEK_OF_YEAR} field range from 1 to 53. The first week of a
* calendar year is the earliest seven day period starting on {@link
* Calendar#getFirstDayOfWeek() getFirstDayOfWeek()} that contains at
* least {@link Calendar#getMinimalDaysInFirstWeek()
* getMinimalDaysInFirstWeek()} days from that year. It thus depends
* on the values of {@code getMinimalDaysInFirstWeek()}, {@code
* getFirstDayOfWeek()}, and the day of the week of January 1. Weeks
* between week 1 of one year and week 1 of the following year
* (exclusive) are numbered sequentially from 2 to 52 or 53 (except
* for year(s) involved in the Julian-Gregorian transition).
*
* <p>The {@code getFirstDayOfWeek()} and {@code
* getMinimalDaysInFirstWeek()} values are initialized using
* locale-dependent resources when constructing a {@code
* GregorianCalendar}. <a id="iso8601_compatible_setting">The week
* determination is compatible</a> with the ISO 8601 standard when {@code
* getFirstDayOfWeek()} is {@code MONDAY} and {@code
* getMinimalDaysInFirstWeek()} is 4, which values are used in locales
* where the standard is preferred. These values can explicitly be set by
* calling {@link Calendar#setFirstDayOfWeek(int) setFirstDayOfWeek()} and
* {@link Calendar#setMinimalDaysInFirstWeek(int)
* setMinimalDaysInFirstWeek()}.
*
* <p>A <a id="week_year"><em>week year</em></a> is in sync with a
* {@code WEEK_OF_YEAR} cycle. All weeks between the first and last
* weeks (inclusive) have the same <em>week year</em> value.
* Therefore, the first and last days of a week year may have
* different calendar year values.
*
* <p>For example, January 1, 1998 is a Thursday. If {@code
* getFirstDayOfWeek()} is {@code MONDAY} and {@code
* getMinimalDaysInFirstWeek()} is 4 (ISO 8601 standard compatible
* setting), then week 1 of 1998 starts on December 29, 1997, and ends
* on January 4, 1998. The week year is 1998 for the last three days
* of calendar year 1997. If, however, {@code getFirstDayOfWeek()} is
* {@code SUNDAY}, then week 1 of 1998 starts on January 4, 1998, and
* ends on January 10, 1998; the first three days of 1998 then are
* part of week 53 of 1997 and their week year is 1997.
*
* <h3>Week Of Month</h3>
*
* <p>Values calculated for the {@code WEEK_OF_MONTH} field range from 0
* to 6. Week 1 of a month (the days with <code>WEEK_OF_MONTH =
* 1</code>) is the earliest set of at least
* {@code getMinimalDaysInFirstWeek()} contiguous days in that month,
* ending on the day before {@code getFirstDayOfWeek()}. Unlike
* week 1 of a year, week 1 of a month may be shorter than 7 days, need
* not start on {@code getFirstDayOfWeek()}, and will not include days of
* the previous month. Days of a month before week 1 have a
* {@code WEEK_OF_MONTH} of 0.
*
* <p>For example, if {@code getFirstDayOfWeek()} is {@code SUNDAY}
* and {@code getMinimalDaysInFirstWeek()} is 4, then the first week of
* January 1998 is Sunday, January 4 through Saturday, January 10. These days
* have a {@code WEEK_OF_MONTH} of 1. Thursday, January 1 through
* Saturday, January 3 have a {@code WEEK_OF_MONTH} of 0. If
* {@code getMinimalDaysInFirstWeek()} is changed to 3, then January 1
* through January 3 have a {@code WEEK_OF_MONTH} of 1.
*
* <h3>Default Fields Values</h3>
*
* <p>The {@code clear} method sets calendar field(s)
* undefined. {@code GregorianCalendar} uses the following
* default value for each calendar field if its value is undefined.
*
* <table class="striped" style="text-align: left; width: 66%;">
* <caption style="display:none">GregorianCalendar default field values</caption>
* <thead>
* <tr>
* <th scope="col">
* Field
* </th>
* <th scope="col">
* Default Value
* </th>
* </tr>
* </thead>
* <tbody>
* <tr>
* <th scope="row">
* {@code ERA}
* </th>
* <td>
* {@code AD}
* </td>
* </tr>
* <tr>
* <th scope="row">
* {@code YEAR}
* </th>
* <td>
* {@code 1970}
* </td>
* </tr>
* <tr>
* <th scope="row">
* {@code MONTH}
* </th>
* <td>
* {@code JANUARY}
* </td>
* </tr>
* <tr>
* <th scope="row">
* {@code DAY_OF_MONTH}
* </th>
* <td>
* {@code 1}
* </td>
* </tr>
* <tr>
* <th scope="row">
* {@code DAY_OF_WEEK}
* </th>
* <td>
* {@code the first day of week}
* </td>
* </tr>
* <tr>
* <th scope="row">
* {@code WEEK_OF_MONTH}
* </th>
* <td>
* {@code 0}
* </td>
* </tr>
* <tr>
* <th scope="row">
* {@code DAY_OF_WEEK_IN_MONTH}
* </th>
* <td>
* {@code 1}
* </td>
* </tr>
* <tr>
* <th scope="row">
* {@code AM_PM}
* </th>
* <td>
* {@code AM}
* </td>
* </tr>
* <tr>
* <th scope="row">
* {@code HOUR, HOUR_OF_DAY, MINUTE, SECOND, MILLISECOND}
* </th>
* <td>
* {@code 0}
* </td>
* </tr>
* </tbody>
* </table>
* <br>Default values are not applicable for the fields not listed above.
*
* <p>
* <strong>Example:</strong>
* <blockquote>
* <pre>
* // get the supported ids for GMT-08:00 (Pacific Standard Time)
* String[] ids = TimeZone.getAvailableIDs(-8 * 60 * 60 * 1000);
* // if no ids were returned, something is wrong. get out.
* if (ids.length == 0)
* System.exit(0);
*
* // begin output
* System.out.println("Current Time");
*
* // create a Pacific Standard Time time zone
* SimpleTimeZone pdt = new SimpleTimeZone(-8 * 60 * 60 * 1000, ids[0]);
*
* // set up rules for Daylight Saving Time
* pdt.setStartRule(Calendar.APRIL, 1, Calendar.SUNDAY, 2 * 60 * 60 * 1000);
* pdt.setEndRule(Calendar.OCTOBER, -1, Calendar.SUNDAY, 2 * 60 * 60 * 1000);
*
* // create a GregorianCalendar with the Pacific Daylight time zone
* // and the current date and time
* Calendar calendar = new GregorianCalendar(pdt);
* Date trialTime = new Date();
* calendar.setTime(trialTime);
*
* // print out a bunch of interesting things
* System.out.println("ERA: " + calendar.get(Calendar.ERA));
* System.out.println("YEAR: " + calendar.get(Calendar.YEAR));
* System.out.println("MONTH: " + calendar.get(Calendar.MONTH));
* System.out.println("WEEK_OF_YEAR: " + calendar.get(Calendar.WEEK_OF_YEAR));
* System.out.println("WEEK_OF_MONTH: " + calendar.get(Calendar.WEEK_OF_MONTH));
* System.out.println("DATE: " + calendar.get(Calendar.DATE));
* System.out.println("DAY_OF_MONTH: " + calendar.get(Calendar.DAY_OF_MONTH));
* System.out.println("DAY_OF_YEAR: " + calendar.get(Calendar.DAY_OF_YEAR));
* System.out.println("DAY_OF_WEEK: " + calendar.get(Calendar.DAY_OF_WEEK));
* System.out.println("DAY_OF_WEEK_IN_MONTH: "
* + calendar.get(Calendar.DAY_OF_WEEK_IN_MONTH));
* System.out.println("AM_PM: " + calendar.get(Calendar.AM_PM));
* System.out.println("HOUR: " + calendar.get(Calendar.HOUR));
* System.out.println("HOUR_OF_DAY: " + calendar.get(Calendar.HOUR_OF_DAY));
* System.out.println("MINUTE: " + calendar.get(Calendar.MINUTE));
* System.out.println("SECOND: " + calendar.get(Calendar.SECOND));
* System.out.println("MILLISECOND: " + calendar.get(Calendar.MILLISECOND));
* System.out.println("ZONE_OFFSET: "
* + (calendar.get(Calendar.ZONE_OFFSET)/(60*60*1000)));
* System.out.println("DST_OFFSET: "
* + (calendar.get(Calendar.DST_OFFSET)/(60*60*1000)));
* System.out.println("Current Time, with hour reset to 3");
* calendar.clear(Calendar.HOUR_OF_DAY); // so doesn't override
* calendar.set(Calendar.HOUR, 3);
* System.out.println("ERA: " + calendar.get(Calendar.ERA));
* System.out.println("YEAR: " + calendar.get(Calendar.YEAR));
* System.out.println("MONTH: " + calendar.get(Calendar.MONTH));
* System.out.println("WEEK_OF_YEAR: " + calendar.get(Calendar.WEEK_OF_YEAR));
* System.out.println("WEEK_OF_MONTH: " + calendar.get(Calendar.WEEK_OF_MONTH));
* System.out.println("DATE: " + calendar.get(Calendar.DATE));
* System.out.println("DAY_OF_MONTH: " + calendar.get(Calendar.DAY_OF_MONTH));
* System.out.println("DAY_OF_YEAR: " + calendar.get(Calendar.DAY_OF_YEAR));
* System.out.println("DAY_OF_WEEK: " + calendar.get(Calendar.DAY_OF_WEEK));
* System.out.println("DAY_OF_WEEK_IN_MONTH: "
* + calendar.get(Calendar.DAY_OF_WEEK_IN_MONTH));
* System.out.println("AM_PM: " + calendar.get(Calendar.AM_PM));
* System.out.println("HOUR: " + calendar.get(Calendar.HOUR));
* System.out.println("HOUR_OF_DAY: " + calendar.get(Calendar.HOUR_OF_DAY));
* System.out.println("MINUTE: " + calendar.get(Calendar.MINUTE));
* System.out.println("SECOND: " + calendar.get(Calendar.SECOND));
* System.out.println("MILLISECOND: " + calendar.get(Calendar.MILLISECOND));
* System.out.println("ZONE_OFFSET: "
* + (calendar.get(Calendar.ZONE_OFFSET)/(60*60*1000))); // in hours
* System.out.println("DST_OFFSET: "
* + (calendar.get(Calendar.DST_OFFSET)/(60*60*1000))); // in hours
* </pre>
* </blockquote>
*
* @see TimeZone
* @author David Goldsmith, Mark Davis, Chen-Lieh Huang, Alan Liu
* @since 1.1
*/
public class GregorianCalendar extends Calendar {
/*
* Implementation Notes
*
* The epoch is the number of days or milliseconds from some defined
* starting point. The epoch for java.util.Date is used here; that is,
* milliseconds from January 1, 1970 (Gregorian), midnight UTC. Other
* epochs which are used are January 1, year 1 (Gregorian), which is day 1
* of the Gregorian calendar, and December 30, year 0 (Gregorian), which is
* day 1 of the Julian calendar.
*
* We implement the proleptic Julian and Gregorian calendars. This means we
* implement the modern definition of the calendar even though the
* historical usage differs. For example, if the Gregorian change is set
* to new Date(Long.MIN_VALUE), we have a pure Gregorian calendar which
* labels dates preceding the invention of the Gregorian calendar in 1582 as
* if the calendar existed then.
*
* Likewise, with the Julian calendar, we assume a consistent
* 4-year leap year rule, even though the historical pattern of
* leap years is irregular, being every 3 years from 45 BCE
* through 9 BCE, then every 4 years from 8 CE onwards, with no
* leap years in-between. Thus date computations and functions
* such as isLeapYear() are not intended to be historically
* accurate.
*/
//////////////////
// Class Variables
//////////////////
Value of the ERA field indicating the period before the common era (before Christ), also known as BCE. The sequence of years at the transition from BC to AD is ..., 2 BC, 1 BC, 1 AD, 2 AD,... See Also:
/**
* Value of the {@code ERA} field indicating
* the period before the common era (before Christ), also known as BCE.
* The sequence of years at the transition from {@code BC} to {@code AD} is
* ..., 2 BC, 1 BC, 1 AD, 2 AD,...
*
* @see #ERA
*/
public static final int BC = 0;
Value of the Calendar.ERA field indicating the period before the common era, the same value as BC. See Also:
/**
* Value of the {@link #ERA} field indicating
* the period before the common era, the same value as {@link #BC}.
*
* @see #CE
*/
static final int BCE = 0;
Value of the ERA field indicating the common era (Anno Domini), also known as CE. The sequence of years at the transition from BC to AD is ..., 2 BC, 1 BC, 1 AD, 2 AD,... See Also:
/**
* Value of the {@code ERA} field indicating
* the common era (Anno Domini), also known as CE.
* The sequence of years at the transition from {@code BC} to {@code AD} is
* ..., 2 BC, 1 BC, 1 AD, 2 AD,...
*
* @see #ERA
*/
public static final int AD = 1;
Value of the Calendar.ERA field indicating the common era, the same value as AD. See Also:
/**
* Value of the {@link #ERA} field indicating
* the common era, the same value as {@link #AD}.
*
* @see #BCE
*/
static final int CE = 1;
private static final int EPOCH_OFFSET = 719163; // Fixed date of January 1, 1970 (Gregorian)
private static final int EPOCH_YEAR = 1970;
static final int MONTH_LENGTH[]
= {31,28,31,30,31,30,31,31,30,31,30,31}; // 0-based
static final int LEAP_MONTH_LENGTH[]
= {31,29,31,30,31,30,31,31,30,31,30,31}; // 0-based
// Useful millisecond constants. Although ONE_DAY and ONE_WEEK can fit
// into ints, they must be longs in order to prevent arithmetic overflow
// when performing (bug 4173516).
private static final int ONE_SECOND = 1000;
private static final int ONE_MINUTE = 60*ONE_SECOND;
private static final int ONE_HOUR = 60*ONE_MINUTE;
private static final long ONE_DAY = 24*ONE_HOUR;
private static final long ONE_WEEK = 7*ONE_DAY;
/*
* <pre>
* Greatest Least
* Field name Minimum Minimum Maximum Maximum
* ---------- ------- ------- ------- -------
* ERA 0 0 1 1
* YEAR 1 1 292269054 292278994
* MONTH 0 0 11 11
* WEEK_OF_YEAR 1 1 52* 53
* WEEK_OF_MONTH 0 0 4* 6
* DAY_OF_MONTH 1 1 28* 31
* DAY_OF_YEAR 1 1 365* 366
* DAY_OF_WEEK 1 1 7 7
* DAY_OF_WEEK_IN_MONTH 1 1 4* 6
* AM_PM 0 0 1 1
* HOUR 0 0 11 11
* HOUR_OF_DAY 0 0 23 23
* MINUTE 0 0 59 59
* SECOND 0 0 59 59
* MILLISECOND 0 0 999 999
* ZONE_OFFSET -13:00 -13:00 14:00 14:00
* DST_OFFSET 0:00 0:00 0:20 2:00
* </pre>
* *: depends on the Gregorian change date
*/
static final int MIN_VALUES[] = {
BCE, // ERA
1, // YEAR
JANUARY, // MONTH
1, // WEEK_OF_YEAR
0, // WEEK_OF_MONTH
1, // DAY_OF_MONTH
1, // DAY_OF_YEAR
SUNDAY, // DAY_OF_WEEK
1, // DAY_OF_WEEK_IN_MONTH
AM, // AM_PM
0, // HOUR
0, // HOUR_OF_DAY
0, // MINUTE
0, // SECOND
0, // MILLISECOND
-13*ONE_HOUR, // ZONE_OFFSET (UNIX compatibility)
0 // DST_OFFSET
};
static final int LEAST_MAX_VALUES[] = {
CE, // ERA
292269054, // YEAR
DECEMBER, // MONTH
52, // WEEK_OF_YEAR
4, // WEEK_OF_MONTH
28, // DAY_OF_MONTH
365, // DAY_OF_YEAR
SATURDAY, // DAY_OF_WEEK
4, // DAY_OF_WEEK_IN
PM, // AM_PM
11, // HOUR
23, // HOUR_OF_DAY
59, // MINUTE
59, // SECOND
999, // MILLISECOND
14*ONE_HOUR, // ZONE_OFFSET
20*ONE_MINUTE // DST_OFFSET (historical least maximum)
};
static final int MAX_VALUES[] = {
CE, // ERA
292278994, // YEAR
DECEMBER, // MONTH
53, // WEEK_OF_YEAR
6, // WEEK_OF_MONTH
31, // DAY_OF_MONTH
366, // DAY_OF_YEAR
SATURDAY, // DAY_OF_WEEK
6, // DAY_OF_WEEK_IN
PM, // AM_PM
11, // HOUR
23, // HOUR_OF_DAY
59, // MINUTE
59, // SECOND
999, // MILLISECOND
14*ONE_HOUR, // ZONE_OFFSET
2*ONE_HOUR // DST_OFFSET (double summer time)
};
// Proclaim serialization compatibility with JDK 1.1
@SuppressWarnings("FieldNameHidesFieldInSuperclass")
@java.io.Serial
static final long serialVersionUID = -8125100834729963327L;
// Reference to the sun.util.calendar.Gregorian instance (singleton).
private static final Gregorian gcal =
CalendarSystem.getGregorianCalendar();
// Reference to the JulianCalendar instance (singleton), set as needed. See
// getJulianCalendarSystem().
private static JulianCalendar jcal;
// JulianCalendar eras. See getJulianCalendarSystem().
private static Era[] jeras;
// The default value of gregorianCutover.
static final long DEFAULT_GREGORIAN_CUTOVER = -12219292800000L;
/////////////////////
// Instance Variables
/////////////////////
The point at which the Gregorian calendar rules are used, measured in
milliseconds from the standard epoch. Default is October 15, 1582
(Gregorian) 00:00:00 UTC or -12219292800000L. For this value, October 4,
1582 (Julian) is followed by October 15, 1582 (Gregorian). This
corresponds to Julian day number 2299161.
@serial
/**
* The point at which the Gregorian calendar rules are used, measured in
* milliseconds from the standard epoch. Default is October 15, 1582
* (Gregorian) 00:00:00 UTC or -12219292800000L. For this value, October 4,
* 1582 (Julian) is followed by October 15, 1582 (Gregorian). This
* corresponds to Julian day number 2299161.
* @serial
*/
private long gregorianCutover = DEFAULT_GREGORIAN_CUTOVER;
The fixed date of the gregorianCutover.
/**
* The fixed date of the gregorianCutover.
*/
private transient long gregorianCutoverDate =
(((DEFAULT_GREGORIAN_CUTOVER + 1)/ONE_DAY) - 1) + EPOCH_OFFSET; // == 577736
The normalized year of the gregorianCutover in Gregorian, with
0 representing 1 BCE, -1 representing 2 BCE, etc.
/**
* The normalized year of the gregorianCutover in Gregorian, with
* 0 representing 1 BCE, -1 representing 2 BCE, etc.
*/
private transient int gregorianCutoverYear = 1582;
The normalized year of the gregorianCutover in Julian, with 0
representing 1 BCE, -1 representing 2 BCE, etc.
/**
* The normalized year of the gregorianCutover in Julian, with 0
* representing 1 BCE, -1 representing 2 BCE, etc.
*/
private transient int gregorianCutoverYearJulian = 1582;
gdate always has a sun.util.calendar.Gregorian.Date instance to
avoid overhead of creating it. The assumption is that most
applications will need only Gregorian calendar calculations.
/**
* gdate always has a sun.util.calendar.Gregorian.Date instance to
* avoid overhead of creating it. The assumption is that most
* applications will need only Gregorian calendar calculations.
*/
private transient BaseCalendar.Date gdate;
Reference to either gdate or a JulianCalendar.Date
instance. After calling complete(), this value is guaranteed to
be set.
/**
* Reference to either gdate or a JulianCalendar.Date
* instance. After calling complete(), this value is guaranteed to
* be set.
*/
private transient BaseCalendar.Date cdate;
The CalendarSystem used to calculate the date in cdate. After
calling complete(), this value is guaranteed to be set and
consistent with the cdate value.
/**
* The CalendarSystem used to calculate the date in cdate. After
* calling complete(), this value is guaranteed to be set and
* consistent with the cdate value.
*/
private transient BaseCalendar calsys;
Temporary int[2] to get time zone offsets. zoneOffsets[0] gets
the GMT offset value and zoneOffsets[1] gets the DST saving
value.
/**
* Temporary int[2] to get time zone offsets. zoneOffsets[0] gets
* the GMT offset value and zoneOffsets[1] gets the DST saving
* value.
*/
private transient int[] zoneOffsets;
Temporary storage for saving original fields[] values in
non-lenient mode.
/**
* Temporary storage for saving original fields[] values in
* non-lenient mode.
*/
private transient int[] originalFields;
///////////////
// Constructors
///////////////
Constructs a default GregorianCalendar using the current time in the default time zone with the default FORMAT locale. /**
* Constructs a default {@code GregorianCalendar} using the current time
* in the default time zone with the default
* {@link Locale.Category#FORMAT FORMAT} locale.
*/
public GregorianCalendar() {
this(TimeZone.getDefaultRef(), Locale.getDefault(Locale.Category.FORMAT));
setZoneShared(true);
}
Constructs a GregorianCalendar based on the current time in the given time zone with the default FORMAT locale. Params: - zone – the given time zone.
/**
* Constructs a {@code GregorianCalendar} based on the current time
* in the given time zone with the default
* {@link Locale.Category#FORMAT FORMAT} locale.
*
* @param zone the given time zone.
*/
public GregorianCalendar(TimeZone zone) {
this(zone, Locale.getDefault(Locale.Category.FORMAT));
}
Constructs a GregorianCalendar based on the current time in the default time zone with the given locale. Params: - aLocale – the given locale.
/**
* Constructs a {@code GregorianCalendar} based on the current time
* in the default time zone with the given locale.
*
* @param aLocale the given locale.
*/
public GregorianCalendar(Locale aLocale) {
this(TimeZone.getDefaultRef(), aLocale);
setZoneShared(true);
}
Constructs a GregorianCalendar based on the current time in the given time zone with the given locale. Params: - zone – the given time zone.
- aLocale – the given locale.
/**
* Constructs a {@code GregorianCalendar} based on the current time
* in the given time zone with the given locale.
*
* @param zone the given time zone.
* @param aLocale the given locale.
*/
public GregorianCalendar(TimeZone zone, Locale aLocale) {
super(zone, aLocale);
gdate = (BaseCalendar.Date) gcal.newCalendarDate(zone);
setTimeInMillis(System.currentTimeMillis());
}
Constructs a GregorianCalendar with the given date set in the default time zone with the default locale. Params: - year – the value used to set the
YEAR calendar field in the calendar. - month – the value used to set the
MONTH calendar field in the calendar. Month value is 0-based. e.g., 0 for January. - dayOfMonth – the value used to set the
DAY_OF_MONTH calendar field in the calendar.
/**
* Constructs a {@code GregorianCalendar} with the given date set
* in the default time zone with the default locale.
*
* @param year the value used to set the {@code YEAR} calendar field in the calendar.
* @param month the value used to set the {@code MONTH} calendar field in the calendar.
* Month value is 0-based. e.g., 0 for January.
* @param dayOfMonth the value used to set the {@code DAY_OF_MONTH} calendar field in the calendar.
*/
public GregorianCalendar(int year, int month, int dayOfMonth) {
this(year, month, dayOfMonth, 0, 0, 0, 0);
}
Constructs a GregorianCalendar with the given date and time set for the default time zone with the default locale. Params: - year – the value used to set the
YEAR calendar field in the calendar. - month – the value used to set the
MONTH calendar field in the calendar. Month value is 0-based. e.g., 0 for January. - dayOfMonth – the value used to set the
DAY_OF_MONTH calendar field in the calendar. - hourOfDay – the value used to set the
HOUR_OF_DAY calendar field in the calendar. - minute – the value used to set the
MINUTE calendar field in the calendar.
/**
* Constructs a {@code GregorianCalendar} with the given date
* and time set for the default time zone with the default locale.
*
* @param year the value used to set the {@code YEAR} calendar field in the calendar.
* @param month the value used to set the {@code MONTH} calendar field in the calendar.
* Month value is 0-based. e.g., 0 for January.
* @param dayOfMonth the value used to set the {@code DAY_OF_MONTH} calendar field in the calendar.
* @param hourOfDay the value used to set the {@code HOUR_OF_DAY} calendar field
* in the calendar.
* @param minute the value used to set the {@code MINUTE} calendar field
* in the calendar.
*/
public GregorianCalendar(int year, int month, int dayOfMonth, int hourOfDay,
int minute) {
this(year, month, dayOfMonth, hourOfDay, minute, 0, 0);
}
Constructs a GregorianCalendar with the given date
and time set for the default time zone with the default locale.
Params: - year – the value used to set the
YEAR calendar field in the calendar. - month – the value used to set the
MONTH calendar field in the calendar. Month value is 0-based. e.g., 0 for January. - dayOfMonth – the value used to set the
DAY_OF_MONTH calendar field in the calendar. - hourOfDay – the value used to set the
HOUR_OF_DAY calendar field in the calendar. - minute – the value used to set the
MINUTE calendar field in the calendar. - second – the value used to set the
SECOND calendar field in the calendar.
/**
* Constructs a GregorianCalendar with the given date
* and time set for the default time zone with the default locale.
*
* @param year the value used to set the {@code YEAR} calendar field in the calendar.
* @param month the value used to set the {@code MONTH} calendar field in the calendar.
* Month value is 0-based. e.g., 0 for January.
* @param dayOfMonth the value used to set the {@code DAY_OF_MONTH} calendar field in the calendar.
* @param hourOfDay the value used to set the {@code HOUR_OF_DAY} calendar field
* in the calendar.
* @param minute the value used to set the {@code MINUTE} calendar field
* in the calendar.
* @param second the value used to set the {@code SECOND} calendar field
* in the calendar.
*/
public GregorianCalendar(int year, int month, int dayOfMonth, int hourOfDay,
int minute, int second) {
this(year, month, dayOfMonth, hourOfDay, minute, second, 0);
}
Constructs a GregorianCalendar with the given date and time set for the default time zone with the default locale. Params: - year – the value used to set the
YEAR calendar field in the calendar. - month – the value used to set the
MONTH calendar field in the calendar. Month value is 0-based. e.g., 0 for January. - dayOfMonth – the value used to set the
DAY_OF_MONTH calendar field in the calendar. - hourOfDay – the value used to set the
HOUR_OF_DAY calendar field in the calendar. - minute – the value used to set the
MINUTE calendar field in the calendar. - second – the value used to set the
SECOND calendar field in the calendar. - millis – the value used to set the
MILLISECOND calendar field
/**
* Constructs a {@code GregorianCalendar} with the given date
* and time set for the default time zone with the default locale.
*
* @param year the value used to set the {@code YEAR} calendar field in the calendar.
* @param month the value used to set the {@code MONTH} calendar field in the calendar.
* Month value is 0-based. e.g., 0 for January.
* @param dayOfMonth the value used to set the {@code DAY_OF_MONTH} calendar field in the calendar.
* @param hourOfDay the value used to set the {@code HOUR_OF_DAY} calendar field
* in the calendar.
* @param minute the value used to set the {@code MINUTE} calendar field
* in the calendar.
* @param second the value used to set the {@code SECOND} calendar field
* in the calendar.
* @param millis the value used to set the {@code MILLISECOND} calendar field
*/
GregorianCalendar(int year, int month, int dayOfMonth,
int hourOfDay, int minute, int second, int millis) {
super();
gdate = (BaseCalendar.Date) gcal.newCalendarDate(getZone());
this.set(YEAR, year);
this.set(MONTH, month);
this.set(DAY_OF_MONTH, dayOfMonth);
// Set AM_PM and HOUR here to set their stamp values before
// setting HOUR_OF_DAY (6178071).
if (hourOfDay >= 12 && hourOfDay <= 23) {
// If hourOfDay is a valid PM hour, set the correct PM values
// so that it won't throw an exception in case it's set to
// non-lenient later.
this.internalSet(AM_PM, PM);
this.internalSet(HOUR, hourOfDay - 12);
} else {
// The default value for AM_PM is AM.
// We don't care any out of range value here for leniency.
this.internalSet(HOUR, hourOfDay);
}
// The stamp values of AM_PM and HOUR must be COMPUTED. (6440854)
setFieldsComputed(HOUR_MASK|AM_PM_MASK);
this.set(HOUR_OF_DAY, hourOfDay);
this.set(MINUTE, minute);
this.set(SECOND, second);
// should be changed to set() when this constructor is made
// public.
this.internalSet(MILLISECOND, millis);
}
Constructs an empty GregorianCalendar.
Params: - zone – the given time zone
- locale – the given locale
- flag – the flag requesting an empty instance
/**
* Constructs an empty GregorianCalendar.
*
* @param zone the given time zone
* @param locale the given locale
* @param flag the flag requesting an empty instance
*/
GregorianCalendar(TimeZone zone, Locale locale, boolean flag) {
super(zone, locale);
gdate = (BaseCalendar.Date) gcal.newCalendarDate(getZone());
}
/////////////////
// Public methods
/////////////////
Sets the GregorianCalendar change date. This is the point when the switch from Julian dates to Gregorian dates occurred. Default is October 15, 1582 (Gregorian). Previous to this, dates will be in the Julian calendar. To obtain a pure Julian calendar, set the change date to Date(Long.MAX_VALUE). To obtain a pure Gregorian calendar, set the change date to Date(Long.MIN_VALUE).
Params: - date – the given Gregorian cutover date.
/**
* Sets the {@code GregorianCalendar} change date. This is the point when the switch
* from Julian dates to Gregorian dates occurred. Default is October 15,
* 1582 (Gregorian). Previous to this, dates will be in the Julian calendar.
* <p>
* To obtain a pure Julian calendar, set the change date to
* {@code Date(Long.MAX_VALUE)}. To obtain a pure Gregorian calendar,
* set the change date to {@code Date(Long.MIN_VALUE)}.
*
* @param date the given Gregorian cutover date.
*/
public void setGregorianChange(Date date) {
long cutoverTime = date.getTime();
if (cutoverTime == gregorianCutover) {
return;
}
// Before changing the cutover date, make sure to have the
// time of this calendar.
complete();
setGregorianChange(cutoverTime);
}
private void setGregorianChange(long cutoverTime) {
gregorianCutover = cutoverTime;
gregorianCutoverDate = CalendarUtils.floorDivide(cutoverTime, ONE_DAY)
+ EPOCH_OFFSET;
// To provide the "pure" Julian calendar as advertised.
// Strictly speaking, the last millisecond should be a
// Gregorian date. However, the API doc specifies that setting
// the cutover date to Long.MAX_VALUE will make this calendar
// a pure Julian calendar. (See 4167995)
if (cutoverTime == Long.MAX_VALUE) {
gregorianCutoverDate++;
}
BaseCalendar.Date d = getGregorianCutoverDate();
// Set the cutover year (in the Gregorian year numbering)
gregorianCutoverYear = d.getYear();
BaseCalendar julianCal = getJulianCalendarSystem();
d = (BaseCalendar.Date) julianCal.newCalendarDate(TimeZone.NO_TIMEZONE);
julianCal.getCalendarDateFromFixedDate(d, gregorianCutoverDate - 1);
gregorianCutoverYearJulian = d.getNormalizedYear();
if (time < gregorianCutover) {
// The field values are no longer valid under the new
// cutover date.
setUnnormalized();
}
}
Gets the Gregorian Calendar change date. This is the point when the
switch from Julian dates to Gregorian dates occurred. Default is
October 15, 1582 (Gregorian). Previous to this, dates will be in the Julian
calendar.
Returns: the Gregorian cutover date for this GregorianCalendar object.
/**
* Gets the Gregorian Calendar change date. This is the point when the
* switch from Julian dates to Gregorian dates occurred. Default is
* October 15, 1582 (Gregorian). Previous to this, dates will be in the Julian
* calendar.
*
* @return the Gregorian cutover date for this {@code GregorianCalendar} object.
*/
public final Date getGregorianChange() {
return new Date(gregorianCutover);
}
Determines if the given year is a leap year. Returns true if the given year is a leap year. To specify BC year numbers, 1 - year number must be given. For example, year BC 4 is specified as -3. Params: - year – the given year.
Returns: true if the given year is a leap year; false otherwise.
/**
* Determines if the given year is a leap year. Returns {@code true} if
* the given year is a leap year. To specify BC year numbers,
* {@code 1 - year number} must be given. For example, year BC 4 is
* specified as -3.
*
* @param year the given year.
* @return {@code true} if the given year is a leap year; {@code false} otherwise.
*/
public boolean isLeapYear(int year) {
if ((year & 3) != 0) {
return false;
}
if (year > gregorianCutoverYear) {
return (year%100 != 0) || (year%400 == 0); // Gregorian
}
if (year < gregorianCutoverYearJulian) {
return true; // Julian
}
boolean gregorian;
// If the given year is the Gregorian cutover year, we need to
// determine which calendar system to be applied to February in the year.
if (gregorianCutoverYear == gregorianCutoverYearJulian) {
BaseCalendar.Date d = getCalendarDate(gregorianCutoverDate); // Gregorian
gregorian = d.getMonth() < BaseCalendar.MARCH;
} else {
gregorian = year == gregorianCutoverYear;
}
return gregorian ? (year%100 != 0) || (year%400 == 0) : true;
}
Returns "gregory" as the calendar type. Returns: "gregory"Since: 1.8
/**
* Returns {@code "gregory"} as the calendar type.
*
* @return {@code "gregory"}
* @since 1.8
*/
@Override
public String getCalendarType() {
return "gregory";
}
Compares this GregorianCalendar to the specified Object. The result is true if and only if the argument is a GregorianCalendar object that represents the same time value (millisecond offset from the Epoch) under the same Calendar parameters and Gregorian change date as this object. Params: - obj – the object to compare with.
See Also: Returns: true if this object is equal to obj; false otherwise.
/**
* Compares this {@code GregorianCalendar} to the specified
* {@code Object}. The result is {@code true} if and
* only if the argument is a {@code GregorianCalendar} object
* that represents the same time value (millisecond offset from
* the <a href="Calendar.html#Epoch">Epoch</a>) under the same
* {@code Calendar} parameters and Gregorian change date as
* this object.
*
* @param obj the object to compare with.
* @return {@code true} if this object is equal to {@code obj};
* {@code false} otherwise.
* @see Calendar#compareTo(Calendar)
*/
@Override
public boolean equals(Object obj) {
return obj instanceof GregorianCalendar &&
super.equals(obj) &&
gregorianCutover == ((GregorianCalendar)obj).gregorianCutover;
}
Generates the hash code for this GregorianCalendar object. /**
* Generates the hash code for this {@code GregorianCalendar} object.
*/
@Override
public int hashCode() {
return super.hashCode() ^ (int)gregorianCutoverDate;
}
Adds the specified (signed) amount of time to the given calendar field,
based on the calendar's rules.
Add rule 1. The value of field after the call minus the value of field before the call is amount, modulo any overflow that has occurred in field. Overflow occurs when a field value exceeds its range and, as a result, the next larger field is incremented or decremented and the field value is adjusted back into its range.
Add rule 2. If a smaller field is expected to be invariant, but it is impossible for it to be equal to its prior value because of changes in its minimum or maximum after field is changed, then its value is adjusted to be as close as possible to its expected value. A smaller field represents a smaller unit of time. HOUR is a smaller field than DAY_OF_MONTH. No adjustment is made to smaller fields that are not expected to be invariant. The calendar system determines what fields are expected to be invariant.
Params: - field – the calendar field.
- amount – the amount of date or time to be added to the field.
Throws: - IllegalArgumentException – if
field is ZONE_OFFSET, DST_OFFSET, or unknown, or if any calendar fields have out-of-range values in non-lenient mode.
/**
* Adds the specified (signed) amount of time to the given calendar field,
* based on the calendar's rules.
*
* <p><em>Add rule 1</em>. The value of {@code field}
* after the call minus the value of {@code field} before the
* call is {@code amount}, modulo any overflow that has occurred in
* {@code field}. Overflow occurs when a field value exceeds its
* range and, as a result, the next larger field is incremented or
* decremented and the field value is adjusted back into its range.</p>
*
* <p><em>Add rule 2</em>. If a smaller field is expected to be
* invariant, but it is impossible for it to be equal to its
* prior value because of changes in its minimum or maximum after
* {@code field} is changed, then its value is adjusted to be as close
* as possible to its expected value. A smaller field represents a
* smaller unit of time. {@code HOUR} is a smaller field than
* {@code DAY_OF_MONTH}. No adjustment is made to smaller fields
* that are not expected to be invariant. The calendar system
* determines what fields are expected to be invariant.</p>
*
* @param field the calendar field.
* @param amount the amount of date or time to be added to the field.
* @throws IllegalArgumentException if {@code field} is
* {@code ZONE_OFFSET}, {@code DST_OFFSET}, or unknown,
* or if any calendar fields have out-of-range values in
* non-lenient mode.
*/
@Override
public void add(int field, int amount) {
// If amount == 0, do nothing even the given field is out of
// range. This is tested by JCK.
if (amount == 0) {
return; // Do nothing!
}
if (field < 0 || field >= ZONE_OFFSET) {
throw new IllegalArgumentException();
}
// Sync the time and calendar fields.
complete();
if (field == YEAR) {
int year = internalGet(YEAR);
if (internalGetEra() == CE) {
year += amount;
if (year > 0) {
set(YEAR, year);
} else { // year <= 0
set(YEAR, 1 - year);
// if year == 0, you get 1 BCE.
set(ERA, BCE);
}
}
else { // era == BCE
year -= amount;
if (year > 0) {
set(YEAR, year);
} else { // year <= 0
set(YEAR, 1 - year);
// if year == 0, you get 1 CE
set(ERA, CE);
}
}
pinDayOfMonth();
} else if (field == MONTH) {
int month = internalGet(MONTH) + amount;
int year = internalGet(YEAR);
int y_amount;
if (month >= 0) {
y_amount = month/12;
} else {
y_amount = (month+1)/12 - 1;
}
if (y_amount != 0) {
if (internalGetEra() == CE) {
year += y_amount;
if (year > 0) {
set(YEAR, year);
} else { // year <= 0
set(YEAR, 1 - year);
// if year == 0, you get 1 BCE
set(ERA, BCE);
}
}
else { // era == BCE
year -= y_amount;
if (year > 0) {
set(YEAR, year);
} else { // year <= 0
set(YEAR, 1 - year);
// if year == 0, you get 1 CE
set(ERA, CE);
}
}
}
if (month >= 0) {
set(MONTH, month % 12);
} else {
// month < 0
month %= 12;
if (month < 0) {
month += 12;
}
set(MONTH, JANUARY + month);
}
pinDayOfMonth();
} else if (field == ERA) {
int era = internalGet(ERA) + amount;
if (era < 0) {
era = 0;
}
if (era > 1) {
era = 1;
}
set(ERA, era);
} else {
long delta = amount;
long timeOfDay = 0;
switch (field) {
// Handle the time fields here. Convert the given
// amount to milliseconds and call setTimeInMillis.
case HOUR:
case HOUR_OF_DAY:
delta *= 60 * 60 * 1000; // hours to minutes
break;
case MINUTE:
delta *= 60 * 1000; // minutes to seconds
break;
case SECOND:
delta *= 1000; // seconds to milliseconds
break;
case MILLISECOND:
break;
// Handle week, day and AM_PM fields which involves
// time zone offset change adjustment. Convert the
// given amount to the number of days.
case WEEK_OF_YEAR:
case WEEK_OF_MONTH:
case DAY_OF_WEEK_IN_MONTH:
delta *= 7;
break;
case DAY_OF_MONTH: // synonym of DATE
case DAY_OF_YEAR:
case DAY_OF_WEEK:
break;
case AM_PM:
// Convert the amount to the number of days (delta)
// and +12 or -12 hours (timeOfDay).
delta = amount / 2;
timeOfDay = 12 * (amount % 2);
break;
}
// The time fields don't require time zone offset change
// adjustment.
if (field >= HOUR) {
setTimeInMillis(time + delta);
return;
}
// The rest of the fields (week, day or AM_PM fields)
// require time zone offset (both GMT and DST) change
// adjustment.
// Translate the current time to the fixed date and time
// of the day.
long fd = getCurrentFixedDate();
timeOfDay += internalGet(HOUR_OF_DAY);
timeOfDay *= 60;
timeOfDay += internalGet(MINUTE);
timeOfDay *= 60;
timeOfDay += internalGet(SECOND);
timeOfDay *= 1000;
timeOfDay += internalGet(MILLISECOND);
if (timeOfDay >= ONE_DAY) {
fd++;
timeOfDay -= ONE_DAY;
} else if (timeOfDay < 0) {
fd--;
timeOfDay += ONE_DAY;
}
fd += delta; // fd is the expected fixed date after the calculation
int zoneOffset = internalGet(ZONE_OFFSET) + internalGet(DST_OFFSET);
setTimeInMillis((fd - EPOCH_OFFSET) * ONE_DAY + timeOfDay - zoneOffset);
zoneOffset -= internalGet(ZONE_OFFSET) + internalGet(DST_OFFSET);
// If the time zone offset has changed, then adjust the difference.
if (zoneOffset != 0) {
setTimeInMillis(time + zoneOffset);
long fd2 = getCurrentFixedDate();
// If the adjustment has changed the date, then take
// the previous one.
if (fd2 != fd) {
setTimeInMillis(time - zoneOffset);
}
}
}
}
Adds or subtracts (up/down) a single unit of time on the given time
field without changing larger fields.
Example: Consider a GregorianCalendar originally set to December 31, 1999. Calling roll(Calendar.MONTH, true) sets the calendar to January 31, 1999. The YEAR field is unchanged because it is a larger field than MONTH.
Params: - up – indicates if the value of the specified calendar field is to be rolled up or rolled down. Use
true if rolling up, false otherwise.
Throws: - IllegalArgumentException – if
field is ZONE_OFFSET, DST_OFFSET, or unknown, or if any calendar fields have out-of-range values in non-lenient mode.
See Also:
/**
* Adds or subtracts (up/down) a single unit of time on the given time
* field without changing larger fields.
* <p>
* <em>Example</em>: Consider a {@code GregorianCalendar}
* originally set to December 31, 1999. Calling {@link #roll(int,boolean) roll(Calendar.MONTH, true)}
* sets the calendar to January 31, 1999. The {@code YEAR} field is unchanged
* because it is a larger field than {@code MONTH}.</p>
*
* @param up indicates if the value of the specified calendar field is to be
* rolled up or rolled down. Use {@code true} if rolling up, {@code false} otherwise.
* @throws IllegalArgumentException if {@code field} is
* {@code ZONE_OFFSET}, {@code DST_OFFSET}, or unknown,
* or if any calendar fields have out-of-range values in
* non-lenient mode.
* @see #add(int,int)
* @see #set(int,int)
*/
@Override
public void roll(int field, boolean up) {
roll(field, up ? +1 : -1);
}
Adds a signed amount to the specified calendar field without changing larger fields.
A negative roll amount means to subtract from field without changing
larger fields. If the specified amount is 0, this method performs nothing.
This method calls Calendar.complete() before adding the amount so that all the calendar fields are normalized. If there is any calendar field having an out-of-range value in non-lenient mode, then an IllegalArgumentException is thrown.
Example: Consider a GregorianCalendar originally set to August 31, 1999. Calling roll(Calendar.MONTH,
8) sets the calendar to April 30, 1999. Using a GregorianCalendar, the DAY_OF_MONTH field cannot be 31 in the month April. DAY_OF_MONTH is set to the closest possible value, 30. The YEAR field maintains the value of 1999 because it is a larger field than MONTH.
Example: Consider a GregorianCalendar originally set to Sunday June 6, 1999. Calling roll(Calendar.WEEK_OF_MONTH, -1) sets the calendar to Tuesday June 1, 1999, whereas calling add(Calendar.WEEK_OF_MONTH, -1) sets the calendar to Sunday May 30, 1999. This is because the roll rule imposes an additional constraint: The MONTH must not change when the WEEK_OF_MONTH is rolled. Taken together with add rule 1, the resultant date must be between Tuesday June 1 and Saturday June 5. According to add rule 2, the DAY_OF_WEEK, an invariant when changing the WEEK_OF_MONTH, is set to Tuesday, the closest possible value to Sunday (where Sunday is the first day of the week).
Params: - field – the calendar field.
- amount – the signed amount to add to
field.
Throws: - IllegalArgumentException – if
field is ZONE_OFFSET, DST_OFFSET, or unknown, or if any calendar fields have out-of-range values in non-lenient mode.
See Also: Since: 1.2
/**
* Adds a signed amount to the specified calendar field without changing larger fields.
* A negative roll amount means to subtract from field without changing
* larger fields. If the specified amount is 0, this method performs nothing.
*
* <p>This method calls {@link #complete()} before adding the
* amount so that all the calendar fields are normalized. If there
* is any calendar field having an out-of-range value in non-lenient mode, then an
* {@code IllegalArgumentException} is thrown.
*
* <p>
* <em>Example</em>: Consider a {@code GregorianCalendar}
* originally set to August 31, 1999. Calling <code>roll(Calendar.MONTH,
* 8)</code> sets the calendar to April 30, <strong>1999</strong>. Using a
* {@code GregorianCalendar}, the {@code DAY_OF_MONTH} field cannot
* be 31 in the month April. {@code DAY_OF_MONTH} is set to the closest possible
* value, 30. The {@code YEAR} field maintains the value of 1999 because it
* is a larger field than {@code MONTH}.
* <p>
* <em>Example</em>: Consider a {@code GregorianCalendar}
* originally set to Sunday June 6, 1999. Calling
* {@code roll(Calendar.WEEK_OF_MONTH, -1)} sets the calendar to
* Tuesday June 1, 1999, whereas calling
* {@code add(Calendar.WEEK_OF_MONTH, -1)} sets the calendar to
* Sunday May 30, 1999. This is because the roll rule imposes an
* additional constraint: The {@code MONTH} must not change when the
* {@code WEEK_OF_MONTH} is rolled. Taken together with add rule 1,
* the resultant date must be between Tuesday June 1 and Saturday June
* 5. According to add rule 2, the {@code DAY_OF_WEEK}, an invariant
* when changing the {@code WEEK_OF_MONTH}, is set to Tuesday, the
* closest possible value to Sunday (where Sunday is the first day of the
* week).</p>
*
* @param field the calendar field.
* @param amount the signed amount to add to {@code field}.
* @throws IllegalArgumentException if {@code field} is
* {@code ZONE_OFFSET}, {@code DST_OFFSET}, or unknown,
* or if any calendar fields have out-of-range values in
* non-lenient mode.
* @see #roll(int,boolean)
* @see #add(int,int)
* @see #set(int,int)
* @since 1.2
*/
@Override
public void roll(int field, int amount) {
// If amount == 0, do nothing even the given field is out of
// range. This is tested by JCK.
if (amount == 0) {
return;
}
if (field < 0 || field >= ZONE_OFFSET) {
throw new IllegalArgumentException();
}
// Sync the time and calendar fields.
complete();
int min = getMinimum(field);
int max = getMaximum(field);
switch (field) {
case AM_PM:
case ERA:
case YEAR:
case MINUTE:
case SECOND:
case MILLISECOND:
// These fields are handled simply, since they have fixed minima
// and maxima. The field DAY_OF_MONTH is almost as simple. Other
// fields are complicated, since the range within they must roll
// varies depending on the date.
break;
case HOUR:
case HOUR_OF_DAY:
{
int rolledValue = getRolledValue(internalGet(field), amount, min, max);
int hourOfDay = rolledValue;
if (field == HOUR && internalGet(AM_PM) == PM) {
hourOfDay += 12;
}
// Create the current date/time value to perform wall-clock-based
// roll.
CalendarDate d = calsys.getCalendarDate(time, getZone());
d.setHours(hourOfDay);
time = calsys.getTime(d);
// If we stay on the same wall-clock time, try the next or previous hour.
if (internalGet(HOUR_OF_DAY) == d.getHours()) {
hourOfDay = getRolledValue(rolledValue, amount > 0 ? +1 : -1, min, max);
if (field == HOUR && internalGet(AM_PM) == PM) {
hourOfDay += 12;
}
d.setHours(hourOfDay);
time = calsys.getTime(d);
}
// Get the new hourOfDay value which might have changed due to a DST transition.
hourOfDay = d.getHours();
// Update the hour related fields
internalSet(HOUR_OF_DAY, hourOfDay);
internalSet(AM_PM, hourOfDay / 12);
internalSet(HOUR, hourOfDay % 12);
// Time zone offset and/or daylight saving might have changed.
int zoneOffset = d.getZoneOffset();
int saving = d.getDaylightSaving();
internalSet(ZONE_OFFSET, zoneOffset - saving);
internalSet(DST_OFFSET, saving);
return;
}
case MONTH:
// Rolling the month involves both pinning the final value to [0, 11]
// and adjusting the DAY_OF_MONTH if necessary. We only adjust the
// DAY_OF_MONTH if, after updating the MONTH field, it is illegal.
// E.g., <jan31>.roll(MONTH, 1) -> <feb28> or <feb29>.
{
if (!isCutoverYear(cdate.getNormalizedYear())) {
int mon = (internalGet(MONTH) + amount) % 12;
if (mon < 0) {
mon += 12;
}
set(MONTH, mon);
// Keep the day of month in the range. We don't want to spill over
// into the next month; e.g., we don't want jan31 + 1 mo -> feb31 ->
// mar3.
int monthLen = monthLength(mon);
if (internalGet(DAY_OF_MONTH) > monthLen) {
set(DAY_OF_MONTH, monthLen);
}
} else {
// We need to take care of different lengths in
// year and month due to the cutover.
int yearLength = getActualMaximum(MONTH) + 1;
int mon = (internalGet(MONTH) + amount) % yearLength;
if (mon < 0) {
mon += yearLength;
}
set(MONTH, mon);
int monthLen = getActualMaximum(DAY_OF_MONTH);
if (internalGet(DAY_OF_MONTH) > monthLen) {
set(DAY_OF_MONTH, monthLen);
}
}
return;
}
case WEEK_OF_YEAR:
{
int y = cdate.getNormalizedYear();
max = getActualMaximum(WEEK_OF_YEAR);
set(DAY_OF_WEEK, internalGet(DAY_OF_WEEK));
int woy = internalGet(WEEK_OF_YEAR);
int value = woy + amount;
if (!isCutoverYear(y)) {
int weekYear = getWeekYear();
if (weekYear == y) {
// If the new value is in between min and max
// (exclusive), then we can use the value.
if (value > min && value < max) {
set(WEEK_OF_YEAR, value);
return;
}
long fd = getCurrentFixedDate();
// Make sure that the min week has the current DAY_OF_WEEK
// in the calendar year
long day1 = fd - (7 * (woy - min));
if (calsys.getYearFromFixedDate(day1) != y) {
min++;
}
// Make sure the same thing for the max week
fd += 7 * (max - internalGet(WEEK_OF_YEAR));
if (calsys.getYearFromFixedDate(fd) != y) {
max--;
}
} else {
// When WEEK_OF_YEAR and YEAR are out of sync,
// adjust woy and amount to stay in the calendar year.
if (weekYear > y) {
if (amount < 0) {
amount++;
}
woy = max;
} else {
if (amount > 0) {
amount -= woy - max;
}
woy = min;
}
}
set(field, getRolledValue(woy, amount, min, max));
return;
}
// Handle cutover here.
long fd = getCurrentFixedDate();
BaseCalendar cal;
if (gregorianCutoverYear == gregorianCutoverYearJulian) {
cal = getCutoverCalendarSystem();
} else if (y == gregorianCutoverYear) {
cal = gcal;
} else {
cal = getJulianCalendarSystem();
}
long day1 = fd - (7 * (woy - min));
// Make sure that the min week has the current DAY_OF_WEEK
if (cal.getYearFromFixedDate(day1) != y) {
min++;
}
// Make sure the same thing for the max week
fd += 7 * (max - woy);
cal = (fd >= gregorianCutoverDate) ? gcal : getJulianCalendarSystem();
if (cal.getYearFromFixedDate(fd) != y) {
max--;
}
// value: the new WEEK_OF_YEAR which must be converted
// to month and day of month.
value = getRolledValue(woy, amount, min, max) - 1;
BaseCalendar.Date d = getCalendarDate(day1 + value * 7);
set(MONTH, d.getMonth() - 1);
set(DAY_OF_MONTH, d.getDayOfMonth());
return;
}
case WEEK_OF_MONTH:
{
boolean isCutoverYear = isCutoverYear(cdate.getNormalizedYear());
// dow: relative day of week from first day of week
int dow = internalGet(DAY_OF_WEEK) - getFirstDayOfWeek();
if (dow < 0) {
dow += 7;
}
long fd = getCurrentFixedDate();
long month1; // fixed date of the first day (usually 1) of the month
int monthLength; // actual month length
if (isCutoverYear) {
month1 = getFixedDateMonth1(cdate, fd);
monthLength = actualMonthLength();
} else {
month1 = fd - internalGet(DAY_OF_MONTH) + 1;
monthLength = calsys.getMonthLength(cdate);
}
// the first day of week of the month.
long monthDay1st = BaseCalendar.getDayOfWeekDateOnOrBefore(month1 + 6,
getFirstDayOfWeek());
// if the week has enough days to form a week, the
// week starts from the previous month.
if ((int)(monthDay1st - month1) >= getMinimalDaysInFirstWeek()) {
monthDay1st -= 7;
}
max = getActualMaximum(field);
// value: the new WEEK_OF_MONTH value
int value = getRolledValue(internalGet(field), amount, 1, max) - 1;
// nfd: fixed date of the rolled date
long nfd = monthDay1st + value * 7 + dow;
// Unlike WEEK_OF_YEAR, we need to change day of week if the
// nfd is out of the month.
if (nfd < month1) {
nfd = month1;
} else if (nfd >= (month1 + monthLength)) {
nfd = month1 + monthLength - 1;
}
int dayOfMonth;
if (isCutoverYear) {
// If we are in the cutover year, convert nfd to
// its calendar date and use dayOfMonth.
BaseCalendar.Date d = getCalendarDate(nfd);
dayOfMonth = d.getDayOfMonth();
} else {
dayOfMonth = (int)(nfd - month1) + 1;
}
set(DAY_OF_MONTH, dayOfMonth);
return;
}
case DAY_OF_MONTH:
{
if (!isCutoverYear(cdate.getNormalizedYear())) {
max = calsys.getMonthLength(cdate);
break;
}
// Cutover year handling
long fd = getCurrentFixedDate();
long month1 = getFixedDateMonth1(cdate, fd);
// It may not be a regular month. Convert the date and range to
// the relative values, perform the roll, and
// convert the result back to the rolled date.
int value = getRolledValue((int)(fd - month1), amount, 0, actualMonthLength() - 1);
BaseCalendar.Date d = getCalendarDate(month1 + value);
assert d.getMonth()-1 == internalGet(MONTH);
set(DAY_OF_MONTH, d.getDayOfMonth());
return;
}
case DAY_OF_YEAR:
{
max = getActualMaximum(field);
if (!isCutoverYear(cdate.getNormalizedYear())) {
break;
}
// Handle cutover here.
long fd = getCurrentFixedDate();
long jan1 = fd - internalGet(DAY_OF_YEAR) + 1;
int value = getRolledValue((int)(fd - jan1) + 1, amount, min, max);
BaseCalendar.Date d = getCalendarDate(jan1 + value - 1);
set(MONTH, d.getMonth() - 1);
set(DAY_OF_MONTH, d.getDayOfMonth());
return;
}
case DAY_OF_WEEK:
{
if (!isCutoverYear(cdate.getNormalizedYear())) {
// If the week of year is in the same year, we can
// just change DAY_OF_WEEK.
int weekOfYear = internalGet(WEEK_OF_YEAR);
if (weekOfYear > 1 && weekOfYear < 52) {
set(WEEK_OF_YEAR, weekOfYear); // update stamp[WEEK_OF_YEAR]
max = SATURDAY;
break;
}
}
// We need to handle it in a different way around year
// boundaries and in the cutover year. Note that
// changing era and year values violates the roll
// rule: not changing larger calendar fields...
amount %= 7;
if (amount == 0) {
return;
}
long fd = getCurrentFixedDate();
long dowFirst = BaseCalendar.getDayOfWeekDateOnOrBefore(fd, getFirstDayOfWeek());
fd += amount;
if (fd < dowFirst) {
fd += 7;
} else if (fd >= dowFirst + 7) {
fd -= 7;
}
BaseCalendar.Date d = getCalendarDate(fd);
set(ERA, (d.getNormalizedYear() <= 0 ? BCE : CE));
set(d.getYear(), d.getMonth() - 1, d.getDayOfMonth());
return;
}
case DAY_OF_WEEK_IN_MONTH:
{
min = 1; // after normalized, min should be 1.
if (!isCutoverYear(cdate.getNormalizedYear())) {
int dom = internalGet(DAY_OF_MONTH);
int monthLength = calsys.getMonthLength(cdate);
int lastDays = monthLength % 7;
max = monthLength / 7;
int x = (dom - 1) % 7;
if (x < lastDays) {
max++;
}
set(DAY_OF_WEEK, internalGet(DAY_OF_WEEK));
break;
}
// Cutover year handling
long fd = getCurrentFixedDate();
long month1 = getFixedDateMonth1(cdate, fd);
int monthLength = actualMonthLength();
int lastDays = monthLength % 7;
max = monthLength / 7;
int x = (int)(fd - month1) % 7;
if (x < lastDays) {
max++;
}
int value = getRolledValue(internalGet(field), amount, min, max) - 1;
fd = month1 + value * 7 + x;
BaseCalendar cal = (fd >= gregorianCutoverDate) ? gcal : getJulianCalendarSystem();
BaseCalendar.Date d = (BaseCalendar.Date) cal.newCalendarDate(TimeZone.NO_TIMEZONE);
cal.getCalendarDateFromFixedDate(d, fd);
set(DAY_OF_MONTH, d.getDayOfMonth());
return;
}
}
set(field, getRolledValue(internalGet(field), amount, min, max));
}
Returns the minimum value for the given calendar field of this GregorianCalendar instance. The minimum value is defined as the smallest value returned by the get method for any possible time value, taking into consideration the current values of the getFirstDayOfWeek, getMinimalDaysInFirstWeek, getGregorianChange and getTimeZone methods. Params: - field – the calendar field.
See Also: Returns: the minimum value for the given calendar field.
/**
* Returns the minimum value for the given calendar field of this
* {@code GregorianCalendar} instance. The minimum value is
* defined as the smallest value returned by the {@link
* Calendar#get(int) get} method for any possible time value,
* taking into consideration the current values of the
* {@link Calendar#getFirstDayOfWeek() getFirstDayOfWeek},
* {@link Calendar#getMinimalDaysInFirstWeek() getMinimalDaysInFirstWeek},
* {@link #getGregorianChange() getGregorianChange} and
* {@link Calendar#getTimeZone() getTimeZone} methods.
*
* @param field the calendar field.
* @return the minimum value for the given calendar field.
* @see #getMaximum(int)
* @see #getGreatestMinimum(int)
* @see #getLeastMaximum(int)
* @see #getActualMinimum(int)
* @see #getActualMaximum(int)
*/
@Override
public int getMinimum(int field) {
return MIN_VALUES[field];
}
Returns the maximum value for the given calendar field of this GregorianCalendar instance. The maximum value is defined as the largest value returned by the get method for any possible time value, taking into consideration the current values of the getFirstDayOfWeek, getMinimalDaysInFirstWeek, getGregorianChange and getTimeZone methods. Params: - field – the calendar field.
See Also: Returns: the maximum value for the given calendar field.
/**
* Returns the maximum value for the given calendar field of this
* {@code GregorianCalendar} instance. The maximum value is
* defined as the largest value returned by the {@link
* Calendar#get(int) get} method for any possible time value,
* taking into consideration the current values of the
* {@link Calendar#getFirstDayOfWeek() getFirstDayOfWeek},
* {@link Calendar#getMinimalDaysInFirstWeek() getMinimalDaysInFirstWeek},
* {@link #getGregorianChange() getGregorianChange} and
* {@link Calendar#getTimeZone() getTimeZone} methods.
*
* @param field the calendar field.
* @return the maximum value for the given calendar field.
* @see #getMinimum(int)
* @see #getGreatestMinimum(int)
* @see #getLeastMaximum(int)
* @see #getActualMinimum(int)
* @see #getActualMaximum(int)
*/
@Override
public int getMaximum(int field) {
switch (field) {
case MONTH:
case DAY_OF_MONTH:
case DAY_OF_YEAR:
case WEEK_OF_YEAR:
case WEEK_OF_MONTH:
case DAY_OF_WEEK_IN_MONTH:
case YEAR:
{
// On or after Gregorian 200-3-1, Julian and Gregorian
// calendar dates are the same or Gregorian dates are
// larger (i.e., there is a "gap") after 300-3-1.
if (gregorianCutoverYear > 200) {
break;
}
// There might be "overlapping" dates.
GregorianCalendar gc = (GregorianCalendar) clone();
gc.setLenient(true);
gc.setTimeInMillis(gregorianCutover);
int v1 = gc.getActualMaximum(field);
gc.setTimeInMillis(gregorianCutover-1);
int v2 = gc.getActualMaximum(field);
return Math.max(MAX_VALUES[field], Math.max(v1, v2));
}
}
return MAX_VALUES[field];
}
Returns the highest minimum value for the given calendar field of this GregorianCalendar instance. The highest minimum value is defined as the largest value returned by getActualMinimum(int) for any possible time value, taking into consideration the current values of the getFirstDayOfWeek, getMinimalDaysInFirstWeek, getGregorianChange and getTimeZone methods. Params: - field – the calendar field.
See Also: Returns: the highest minimum value for the given calendar field.
/**
* Returns the highest minimum value for the given calendar field
* of this {@code GregorianCalendar} instance. The highest
* minimum value is defined as the largest value returned by
* {@link #getActualMinimum(int)} for any possible time value,
* taking into consideration the current values of the
* {@link Calendar#getFirstDayOfWeek() getFirstDayOfWeek},
* {@link Calendar#getMinimalDaysInFirstWeek() getMinimalDaysInFirstWeek},
* {@link #getGregorianChange() getGregorianChange} and
* {@link Calendar#getTimeZone() getTimeZone} methods.
*
* @param field the calendar field.
* @return the highest minimum value for the given calendar field.
* @see #getMinimum(int)
* @see #getMaximum(int)
* @see #getLeastMaximum(int)
* @see #getActualMinimum(int)
* @see #getActualMaximum(int)
*/
@Override
public int getGreatestMinimum(int field) {
if (field == DAY_OF_MONTH) {
BaseCalendar.Date d = getGregorianCutoverDate();
long mon1 = getFixedDateMonth1(d, gregorianCutoverDate);
d = getCalendarDate(mon1);
return Math.max(MIN_VALUES[field], d.getDayOfMonth());
}
return MIN_VALUES[field];
}
Returns the lowest maximum value for the given calendar field of this GregorianCalendar instance. The lowest maximum value is defined as the smallest value returned by getActualMaximum(int) for any possible time value, taking into consideration the current values of the getFirstDayOfWeek, getMinimalDaysInFirstWeek, getGregorianChange and getTimeZone methods. Params: - field – the calendar field
See Also: Returns: the lowest maximum value for the given calendar field.
/**
* Returns the lowest maximum value for the given calendar field
* of this {@code GregorianCalendar} instance. The lowest
* maximum value is defined as the smallest value returned by
* {@link #getActualMaximum(int)} for any possible time value,
* taking into consideration the current values of the
* {@link Calendar#getFirstDayOfWeek() getFirstDayOfWeek},
* {@link Calendar#getMinimalDaysInFirstWeek() getMinimalDaysInFirstWeek},
* {@link #getGregorianChange() getGregorianChange} and
* {@link Calendar#getTimeZone() getTimeZone} methods.
*
* @param field the calendar field
* @return the lowest maximum value for the given calendar field.
* @see #getMinimum(int)
* @see #getMaximum(int)
* @see #getGreatestMinimum(int)
* @see #getActualMinimum(int)
* @see #getActualMaximum(int)
*/
@Override
public int getLeastMaximum(int field) {
switch (field) {
case MONTH:
case DAY_OF_MONTH:
case DAY_OF_YEAR:
case WEEK_OF_YEAR:
case WEEK_OF_MONTH:
case DAY_OF_WEEK_IN_MONTH:
case YEAR:
{
GregorianCalendar gc = (GregorianCalendar) clone();
gc.setLenient(true);
gc.setTimeInMillis(gregorianCutover);
int v1 = gc.getActualMaximum(field);
gc.setTimeInMillis(gregorianCutover-1);
int v2 = gc.getActualMaximum(field);
return Math.min(LEAST_MAX_VALUES[field], Math.min(v1, v2));
}
}
return LEAST_MAX_VALUES[field];
}
Returns the minimum value that this calendar field could have, taking into consideration the given time value and the current values of the getFirstDayOfWeek, getMinimalDaysInFirstWeek, getGregorianChange and getTimeZone methods. For example, if the Gregorian change date is January 10, 1970 and the date of this GregorianCalendar is January 20, 1970, the actual minimum value of the DAY_OF_MONTH field is 10 because the previous date of January 10, 1970 is December 27, 1996 (in the Julian calendar). Therefore, December 28, 1969 to January 9, 1970 don't exist.
Params: - field – the calendar field
See Also: Returns: the minimum of the given field for the time value of this GregorianCalendar Since: 1.2
/**
* Returns the minimum value that this calendar field could have,
* taking into consideration the given time value and the current
* values of the
* {@link Calendar#getFirstDayOfWeek() getFirstDayOfWeek},
* {@link Calendar#getMinimalDaysInFirstWeek() getMinimalDaysInFirstWeek},
* {@link #getGregorianChange() getGregorianChange} and
* {@link Calendar#getTimeZone() getTimeZone} methods.
*
* <p>For example, if the Gregorian change date is January 10,
* 1970 and the date of this {@code GregorianCalendar} is
* January 20, 1970, the actual minimum value of the
* {@code DAY_OF_MONTH} field is 10 because the previous date
* of January 10, 1970 is December 27, 1996 (in the Julian
* calendar). Therefore, December 28, 1969 to January 9, 1970
* don't exist.
*
* @param field the calendar field
* @return the minimum of the given field for the time value of
* this {@code GregorianCalendar}
* @see #getMinimum(int)
* @see #getMaximum(int)
* @see #getGreatestMinimum(int)
* @see #getLeastMaximum(int)
* @see #getActualMaximum(int)
* @since 1.2
*/
@Override
public int getActualMinimum(int field) {
if (field == DAY_OF_MONTH) {
GregorianCalendar gc = getNormalizedCalendar();
int year = gc.cdate.getNormalizedYear();
if (year == gregorianCutoverYear || year == gregorianCutoverYearJulian) {
long month1 = getFixedDateMonth1(gc.cdate, gc.calsys.getFixedDate(gc.cdate));
BaseCalendar.Date d = getCalendarDate(month1);
return d.getDayOfMonth();
}
}
return getMinimum(field);
}
Returns the maximum value that this calendar field could have, taking into consideration the given time value and the current values of the getFirstDayOfWeek, getMinimalDaysInFirstWeek, getGregorianChange and getTimeZone methods. For example, if the date of this instance is February 1, 2004, the actual maximum value of the DAY_OF_MONTH field is 29 because 2004 is a leap year, and if the date of this instance is February 1, 2005, it's 28. This method calculates the maximum value of WEEK_OF_YEAR based on the YEAR (calendar year) value, not the week year. Call getWeeksInWeekYear() to get the maximum value of
WEEK_OF_YEAR in the week year of this GregorianCalendar.
Params: - field – the calendar field
See Also: Returns: the maximum of the given field for the time value of this GregorianCalendar Since: 1.2
/**
* Returns the maximum value that this calendar field could have,
* taking into consideration the given time value and the current
* values of the
* {@link Calendar#getFirstDayOfWeek() getFirstDayOfWeek},
* {@link Calendar#getMinimalDaysInFirstWeek() getMinimalDaysInFirstWeek},
* {@link #getGregorianChange() getGregorianChange} and
* {@link Calendar#getTimeZone() getTimeZone} methods.
* For example, if the date of this instance is February 1, 2004,
* the actual maximum value of the {@code DAY_OF_MONTH} field
* is 29 because 2004 is a leap year, and if the date of this
* instance is February 1, 2005, it's 28.
*
* <p>This method calculates the maximum value of {@link
* Calendar#WEEK_OF_YEAR WEEK_OF_YEAR} based on the {@link
* Calendar#YEAR YEAR} (calendar year) value, not the <a
* href="#week_year">week year</a>. Call {@link
* #getWeeksInWeekYear()} to get the maximum value of {@code
* WEEK_OF_YEAR} in the week year of this {@code GregorianCalendar}.
*
* @param field the calendar field
* @return the maximum of the given field for the time value of
* this {@code GregorianCalendar}
* @see #getMinimum(int)
* @see #getMaximum(int)
* @see #getGreatestMinimum(int)
* @see #getLeastMaximum(int)
* @see #getActualMinimum(int)
* @since 1.2
*/
@Override
public int getActualMaximum(int field) {
final int fieldsForFixedMax = ERA_MASK|DAY_OF_WEEK_MASK|HOUR_MASK|AM_PM_MASK|
HOUR_OF_DAY_MASK|MINUTE_MASK|SECOND_MASK|MILLISECOND_MASK|
ZONE_OFFSET_MASK|DST_OFFSET_MASK;
if ((fieldsForFixedMax & (1<<field)) != 0) {
return getMaximum(field);
}
GregorianCalendar gc = getNormalizedCalendar();
BaseCalendar.Date date = gc.cdate;
BaseCalendar cal = gc.calsys;
int normalizedYear = date.getNormalizedYear();
int value = -1;
switch (field) {
case MONTH:
{
if (!gc.isCutoverYear(normalizedYear)) {
value = DECEMBER;
break;
}
// January 1 of the next year may or may not exist.
long nextJan1;
do {
nextJan1 = gcal.getFixedDate(++normalizedYear, BaseCalendar.JANUARY, 1, null);
} while (nextJan1 < gregorianCutoverDate);
BaseCalendar.Date d = (BaseCalendar.Date) date.clone();
cal.getCalendarDateFromFixedDate(d, nextJan1 - 1);
value = d.getMonth() - 1;
}
break;
case DAY_OF_MONTH:
{
value = cal.getMonthLength(date);
if (!gc.isCutoverYear(normalizedYear) || date.getDayOfMonth() == value) {
break;
}
// Handle cutover year.
long fd = gc.getCurrentFixedDate();
if (fd >= gregorianCutoverDate) {
break;
}
int monthLength = gc.actualMonthLength();
long monthEnd = gc.getFixedDateMonth1(gc.cdate, fd) + monthLength - 1;
// Convert the fixed date to its calendar date.
BaseCalendar.Date d = gc.getCalendarDate(monthEnd);
value = d.getDayOfMonth();
}
break;
case DAY_OF_YEAR:
{
if (!gc.isCutoverYear(normalizedYear)) {
value = cal.getYearLength(date);
break;
}
// Handle cutover year.
long jan1;
if (gregorianCutoverYear == gregorianCutoverYearJulian) {
BaseCalendar cocal = gc.getCutoverCalendarSystem();
jan1 = cocal.getFixedDate(normalizedYear, 1, 1, null);
} else if (normalizedYear == gregorianCutoverYearJulian) {
jan1 = cal.getFixedDate(normalizedYear, 1, 1, null);
} else {
jan1 = gregorianCutoverDate;
}
// January 1 of the next year may or may not exist.
long nextJan1 = gcal.getFixedDate(++normalizedYear, 1, 1, null);
if (nextJan1 < gregorianCutoverDate) {
nextJan1 = gregorianCutoverDate;
}
assert jan1 <= cal.getFixedDate(date.getNormalizedYear(), date.getMonth(),
date.getDayOfMonth(), date);
assert nextJan1 >= cal.getFixedDate(date.getNormalizedYear(), date.getMonth(),
date.getDayOfMonth(), date);
value = (int)(nextJan1 - jan1);
}
break;
case WEEK_OF_YEAR:
{
if (!gc.isCutoverYear(normalizedYear)) {
// Get the day of week of January 1 of the year
CalendarDate d = cal.newCalendarDate(TimeZone.NO_TIMEZONE);
d.setDate(date.getYear(), BaseCalendar.JANUARY, 1);
int dayOfWeek = cal.getDayOfWeek(d);
// Normalize the day of week with the firstDayOfWeek value
dayOfWeek -= getFirstDayOfWeek();
if (dayOfWeek < 0) {
dayOfWeek += 7;
}
value = 52;
int magic = dayOfWeek + getMinimalDaysInFirstWeek() - 1;
if ((magic == 6) ||
(date.isLeapYear() && (magic == 5 || magic == 12))) {
value++;
}
break;
}
if (gc == this) {
gc = (GregorianCalendar) gc.clone();
}
int maxDayOfYear = getActualMaximum(DAY_OF_YEAR);
gc.set(DAY_OF_YEAR, maxDayOfYear);
value = gc.get(WEEK_OF_YEAR);
if (internalGet(YEAR) != gc.getWeekYear()) {
gc.set(DAY_OF_YEAR, maxDayOfYear - 7);
value = gc.get(WEEK_OF_YEAR);
}
}
break;
case WEEK_OF_MONTH:
{
if (!gc.isCutoverYear(normalizedYear)) {
CalendarDate d = cal.newCalendarDate(null);
d.setDate(date.getYear(), date.getMonth(), 1);
int dayOfWeek = cal.getDayOfWeek(d);
int monthLength = cal.getMonthLength(d);
dayOfWeek -= getFirstDayOfWeek();
if (dayOfWeek < 0) {
dayOfWeek += 7;
}
int nDaysFirstWeek = 7 - dayOfWeek; // # of days in the first week
value = 3;
if (nDaysFirstWeek >= getMinimalDaysInFirstWeek()) {
value++;
}
monthLength -= nDaysFirstWeek + 7 * 3;
if (monthLength > 0) {
value++;
if (monthLength > 7) {
value++;
}
}
break;
}
// Cutover year handling
if (gc == this) {
gc = (GregorianCalendar) gc.clone();
}
int y = gc.internalGet(YEAR);
int m = gc.internalGet(MONTH);
do {
value = gc.get(WEEK_OF_MONTH);
gc.add(WEEK_OF_MONTH, +1);
} while (gc.get(YEAR) == y && gc.get(MONTH) == m);
}
break;
case DAY_OF_WEEK_IN_MONTH:
{
// may be in the Gregorian cutover month
int ndays, dow1;
int dow = date.getDayOfWeek();
if (!gc.isCutoverYear(normalizedYear)) {
BaseCalendar.Date d = (BaseCalendar.Date) date.clone();
ndays = cal.getMonthLength(d);
d.setDayOfMonth(1);
cal.normalize(d);
dow1 = d.getDayOfWeek();
} else {
// Let a cloned GregorianCalendar take care of the cutover cases.
if (gc == this) {
gc = (GregorianCalendar) clone();
}
ndays = gc.actualMonthLength();
gc.set(DAY_OF_MONTH, gc.getActualMinimum(DAY_OF_MONTH));
dow1 = gc.get(DAY_OF_WEEK);
}
int x = dow - dow1;
if (x < 0) {
x += 7;
}
ndays -= x;
value = (ndays + 6) / 7;
}
break;
case YEAR:
/* The year computation is no different, in principle, from the
* others, however, the range of possible maxima is large. In
* addition, the way we know we've exceeded the range is different.
* For these reasons, we use the special case code below to handle
* this field.
*
* The actual maxima for YEAR depend on the type of calendar:
*
* Gregorian = May 17, 292275056 BCE - Aug 17, 292278994 CE
* Julian = Dec 2, 292269055 BCE - Jan 3, 292272993 CE
* Hybrid = Dec 2, 292269055 BCE - Aug 17, 292278994 CE
*
* We know we've exceeded the maximum when either the month, date,
* time, or era changes in response to setting the year. We don't
* check for month, date, and time here because the year and era are
* sufficient to detect an invalid year setting. NOTE: If code is
* added to check the month and date in the future for some reason,
* Feb 29 must be allowed to shift to Mar 1 when setting the year.
*/
{
if (gc == this) {
gc = (GregorianCalendar) clone();
}
// Calculate the millisecond offset from the beginning
// of the year of this calendar and adjust the max
// year value if we are beyond the limit in the max
// year.
long current = gc.getYearOffsetInMillis();
if (gc.internalGetEra() == CE) {
gc.setTimeInMillis(Long.MAX_VALUE);
value = gc.get(YEAR);
long maxEnd = gc.getYearOffsetInMillis();
if (current > maxEnd) {
value--;
}
} else {
CalendarSystem mincal = gc.getTimeInMillis() >= gregorianCutover ?
gcal : getJulianCalendarSystem();
CalendarDate d = mincal.getCalendarDate(Long.MIN_VALUE, getZone());
long maxEnd = (cal.getDayOfYear(d) - 1) * 24 + d.getHours();
maxEnd *= 60;
maxEnd += d.getMinutes();
maxEnd *= 60;
maxEnd += d.getSeconds();
maxEnd *= 1000;
maxEnd += d.getMillis();
value = d.getYear();
if (value <= 0) {
assert mincal == gcal;
value = 1 - value;
}
if (current < maxEnd) {
value--;
}
}
}
break;
default:
throw new ArrayIndexOutOfBoundsException(field);
}
return value;
}
Returns the millisecond offset from the beginning of this
year. This Calendar object must have been normalized.
/**
* Returns the millisecond offset from the beginning of this
* year. This Calendar object must have been normalized.
*/
private long getYearOffsetInMillis() {
long t = (internalGet(DAY_OF_YEAR) - 1) * 24;
t += internalGet(HOUR_OF_DAY);
t *= 60;
t += internalGet(MINUTE);
t *= 60;
t += internalGet(SECOND);
t *= 1000;
return t + internalGet(MILLISECOND) -
(internalGet(ZONE_OFFSET) + internalGet(DST_OFFSET));
}
@Override
public Object clone()
{
GregorianCalendar other = (GregorianCalendar) super.clone();
other.gdate = (BaseCalendar.Date) gdate.clone();
if (cdate != null) {
if (cdate != gdate) {
other.cdate = (BaseCalendar.Date) cdate.clone();
} else {
other.cdate = other.gdate;
}
}
other.originalFields = null;
other.zoneOffsets = null;
return other;
}
@Override
public TimeZone getTimeZone() {
TimeZone zone = super.getTimeZone();
// To share the zone by CalendarDates
gdate.setZone(zone);
if (cdate != null && cdate != gdate) {
cdate.setZone(zone);
}
return zone;
}
@Override
public void setTimeZone(TimeZone zone) {
super.setTimeZone(zone);
// To share the zone by CalendarDates
gdate.setZone(zone);
if (cdate != null && cdate != gdate) {
cdate.setZone(zone);
}
}
Returns true indicating this GregorianCalendar supports week dates. See Also: Returns: true (always)Since: 1.7
/**
* Returns {@code true} indicating this {@code GregorianCalendar}
* supports week dates.
*
* @return {@code true} (always)
* @see #getWeekYear()
* @see #setWeekDate(int,int,int)
* @see #getWeeksInWeekYear()
* @since 1.7
*/
@Override
public final boolean isWeekDateSupported() {
return true;
}
Returns the week year represented by this GregorianCalendar. The dates in the weeks between 1 and the maximum week number of the week year have the same week year value that may be one year before or after the YEAR (calendar year) value. This method calls Calendar.complete() before calculating the week year.
Throws: - IllegalArgumentException –
if any of the calendar fields is invalid in non-lenient mode.
See Also: Returns: the week year represented by this GregorianCalendar. If the ERA value is BC, the year is represented by 0 or a negative number: BC 1 is 0, BC 2 is -1, BC 3 is -2, and so on. Since: 1.7
/**
* Returns the <a href="#week_year">week year</a> represented by this
* {@code GregorianCalendar}. The dates in the weeks between 1 and the
* maximum week number of the week year have the same week year value
* that may be one year before or after the {@link Calendar#YEAR YEAR}
* (calendar year) value.
*
* <p>This method calls {@link Calendar#complete()} before
* calculating the week year.
*
* @return the week year represented by this {@code GregorianCalendar}.
* If the {@link Calendar#ERA ERA} value is {@link #BC}, the year is
* represented by 0 or a negative number: BC 1 is 0, BC 2
* is -1, BC 3 is -2, and so on.
* @throws IllegalArgumentException
* if any of the calendar fields is invalid in non-lenient mode.
* @see #isWeekDateSupported()
* @see #getWeeksInWeekYear()
* @see Calendar#getFirstDayOfWeek()
* @see Calendar#getMinimalDaysInFirstWeek()
* @since 1.7
*/
@Override
public int getWeekYear() {
int year = get(YEAR); // implicitly calls complete()
if (internalGetEra() == BCE) {
year = 1 - year;
}
// Fast path for the Gregorian calendar years that are never
// affected by the Julian-Gregorian transition
if (year > gregorianCutoverYear + 1) {
int weekOfYear = internalGet(WEEK_OF_YEAR);
if (internalGet(MONTH) == JANUARY) {
if (weekOfYear >= 52) {
--year;
}
} else {
if (weekOfYear == 1) {
++year;
}
}
return year;
}
// General (slow) path
int dayOfYear = internalGet(DAY_OF_YEAR);
int maxDayOfYear = getActualMaximum(DAY_OF_YEAR);
int minimalDays = getMinimalDaysInFirstWeek();
// Quickly check the possibility of year adjustments before
// cloning this GregorianCalendar.
if (dayOfYear > minimalDays && dayOfYear < (maxDayOfYear - 6)) {
return year;
}
// Create a clone to work on the calculation
GregorianCalendar cal = (GregorianCalendar) clone();
cal.setLenient(true);
// Use GMT so that intermediate date calculations won't
// affect the time of day fields.
cal.setTimeZone(TimeZone.getTimeZone("GMT"));
// Go to the first day of the year, which is usually January 1.
cal.set(DAY_OF_YEAR, 1);
cal.complete();
// Get the first day of the first day-of-week in the year.
int delta = getFirstDayOfWeek() - cal.get(DAY_OF_WEEK);
if (delta != 0) {
if (delta < 0) {
delta += 7;
}
cal.add(DAY_OF_YEAR, delta);
}
int minDayOfYear = cal.get(DAY_OF_YEAR);
if (dayOfYear < minDayOfYear) {
if (minDayOfYear <= minimalDays) {
--year;
}
} else {
cal.set(YEAR, year + 1);
cal.set(DAY_OF_YEAR, 1);
cal.complete();
int del = getFirstDayOfWeek() - cal.get(DAY_OF_WEEK);
if (del != 0) {
if (del < 0) {
del += 7;
}
cal.add(DAY_OF_YEAR, del);
}
minDayOfYear = cal.get(DAY_OF_YEAR) - 1;
if (minDayOfYear == 0) {
minDayOfYear = 7;
}
if (minDayOfYear >= minimalDays) {
int days = maxDayOfYear - dayOfYear + 1;
if (days <= (7 - minDayOfYear)) {
++year;
}
}
}
return year;
}
Sets this GregorianCalendar to the date given by the date specifiers - weekYear, weekOfYear, and dayOfWeek. weekOfYear follows the WEEK_OF_YEAR numbering. The dayOfWeek value must be one of the DAY_OF_WEEK values: SUNDAY to SATURDAY. Note that the numeric day-of-week representation differs from the ISO 8601 standard, and that the weekOfYear numbering is compatible with the standard when
getFirstDayOfWeek() is MONDAY and
getMinimalDaysInFirstWeek() is 4.
Unlike the set method, all of the calendar fields and the instant of time value are calculated upon return.
If weekOfYear is out of the valid week-of-year range in weekYear, the weekYear and weekOfYear values are adjusted in lenient mode, or an IllegalArgumentException is thrown in non-lenient mode.
Params: - weekYear – the week year
- weekOfYear – the week number based on
weekYear - dayOfWeek – the day of week value: one of the constants for the
DAY_OF_WEEK field: SUNDAY, ..., SATURDAY.
Throws: - IllegalArgumentException –
if any of the given date specifiers is invalid,
or if any of the calendar fields are inconsistent
with the given date specifiers in non-lenient mode
See Also: Since: 1.7
/**
* Sets this {@code GregorianCalendar} to the date given by the
* date specifiers - <a href="#week_year">{@code weekYear}</a>,
* {@code weekOfYear}, and {@code dayOfWeek}. {@code weekOfYear}
* follows the <a href="#week_and_year">{@code WEEK_OF_YEAR}
* numbering</a>. The {@code dayOfWeek} value must be one of the
* {@link Calendar#DAY_OF_WEEK DAY_OF_WEEK} values: {@link
* Calendar#SUNDAY SUNDAY} to {@link Calendar#SATURDAY SATURDAY}.
*
* <p>Note that the numeric day-of-week representation differs from
* the ISO 8601 standard, and that the {@code weekOfYear}
* numbering is compatible with the standard when {@code
* getFirstDayOfWeek()} is {@code MONDAY} and {@code
* getMinimalDaysInFirstWeek()} is 4.
*
* <p>Unlike the {@code set} method, all of the calendar fields
* and the instant of time value are calculated upon return.
*
* <p>If {@code weekOfYear} is out of the valid week-of-year
* range in {@code weekYear}, the {@code weekYear}
* and {@code weekOfYear} values are adjusted in lenient
* mode, or an {@code IllegalArgumentException} is thrown in
* non-lenient mode.
*
* @param weekYear the week year
* @param weekOfYear the week number based on {@code weekYear}
* @param dayOfWeek the day of week value: one of the constants
* for the {@link #DAY_OF_WEEK DAY_OF_WEEK} field:
* {@link Calendar#SUNDAY SUNDAY}, ...,
* {@link Calendar#SATURDAY SATURDAY}.
* @throws IllegalArgumentException
* if any of the given date specifiers is invalid,
* or if any of the calendar fields are inconsistent
* with the given date specifiers in non-lenient mode
* @see GregorianCalendar#isWeekDateSupported()
* @see Calendar#getFirstDayOfWeek()
* @see Calendar#getMinimalDaysInFirstWeek()
* @since 1.7
*/
@Override
public void setWeekDate(int weekYear, int weekOfYear, int dayOfWeek) {
if (dayOfWeek < SUNDAY || dayOfWeek > SATURDAY) {
throw new IllegalArgumentException("invalid dayOfWeek: " + dayOfWeek);
}
// To avoid changing the time of day fields by date
// calculations, use a clone with the GMT time zone.
GregorianCalendar gc = (GregorianCalendar) clone();
gc.setLenient(true);
int era = gc.get(ERA);
gc.clear();
gc.setTimeZone(TimeZone.getTimeZone("GMT"));
gc.set(ERA, era);
gc.set(YEAR, weekYear);
gc.set(WEEK_OF_YEAR, 1);
gc.set(DAY_OF_WEEK, getFirstDayOfWeek());
int days = dayOfWeek - getFirstDayOfWeek();
if (days < 0) {
days += 7;
}
days += 7 * (weekOfYear - 1);
if (days != 0) {
gc.add(DAY_OF_YEAR, days);
} else {
gc.complete();
}
if (!isLenient() &&
(gc.getWeekYear() != weekYear
|| gc.internalGet(WEEK_OF_YEAR) != weekOfYear
|| gc.internalGet(DAY_OF_WEEK) != dayOfWeek)) {
throw new IllegalArgumentException();
}
set(ERA, gc.internalGet(ERA));
set(YEAR, gc.internalGet(YEAR));
set(MONTH, gc.internalGet(MONTH));
set(DAY_OF_MONTH, gc.internalGet(DAY_OF_MONTH));
// to avoid throwing an IllegalArgumentException in
// non-lenient, set WEEK_OF_YEAR internally
internalSet(WEEK_OF_YEAR, weekOfYear);
complete();
}
Returns the number of weeks in the week year represented by this GregorianCalendar. For example, if this GregorianCalendar's date is December 31, 2008 with the ISO
8601 compatible setting, this method will return 53 for the period: December 29, 2008 to January 3, 2010 while getActualMaximum(WEEK_OF_YEAR) will return 52 for the period: December 31, 2007 to December 28, 2008.
See Also: Returns: the number of weeks in the week year. Since: 1.7
/**
* Returns the number of weeks in the <a href="#week_year">week year</a>
* represented by this {@code GregorianCalendar}.
*
* <p>For example, if this {@code GregorianCalendar}'s date is
* December 31, 2008 with <a href="#iso8601_compatible_setting">the ISO
* 8601 compatible setting</a>, this method will return 53 for the
* period: December 29, 2008 to January 3, 2010 while {@link
* #getActualMaximum(int) getActualMaximum(WEEK_OF_YEAR)} will return
* 52 for the period: December 31, 2007 to December 28, 2008.
*
* @return the number of weeks in the week year.
* @see Calendar#WEEK_OF_YEAR
* @see #getWeekYear()
* @see #getActualMaximum(int)
* @since 1.7
*/
@Override
public int getWeeksInWeekYear() {
GregorianCalendar gc = getNormalizedCalendar();
int weekYear = gc.getWeekYear();
if (weekYear == gc.internalGet(YEAR)) {
return gc.getActualMaximum(WEEK_OF_YEAR);
}
// Use the 2nd week for calculating the max of WEEK_OF_YEAR
if (gc == this) {
gc = (GregorianCalendar) gc.clone();
}
gc.setWeekDate(weekYear, 2, internalGet(DAY_OF_WEEK));
return gc.getActualMaximum(WEEK_OF_YEAR);
}
/////////////////////////////
// Time => Fields computation
/////////////////////////////
The fixed date corresponding to gdate. If the value is
Long.MIN_VALUE, the fixed date value is unknown. Currently,
Julian calendar dates are not cached.
/**
* The fixed date corresponding to gdate. If the value is
* Long.MIN_VALUE, the fixed date value is unknown. Currently,
* Julian calendar dates are not cached.
*/
private transient long cachedFixedDate = Long.MIN_VALUE;
Converts the time value (millisecond offset from the Epoch) to calendar field values.
The time is not recomputed first; to recompute the time, then the fields, call the complete method. See Also:
/**
* Converts the time value (millisecond offset from the <a
* href="Calendar.html#Epoch">Epoch</a>) to calendar field values.
* The time is <em>not</em>
* recomputed first; to recompute the time, then the fields, call the
* {@code complete} method.
*
* @see Calendar#complete
*/
@Override
protected void computeFields() {
int mask;
if (isPartiallyNormalized()) {
// Determine which calendar fields need to be computed.
mask = getSetStateFields();
int fieldMask = ~mask & ALL_FIELDS;
// We have to call computTime in case calsys == null in
// order to set calsys and cdate. (6263644)
if (fieldMask != 0 || calsys == null) {
mask |= computeFields(fieldMask,
mask & (ZONE_OFFSET_MASK|DST_OFFSET_MASK));
assert mask == ALL_FIELDS;
}
} else {
mask = ALL_FIELDS;
computeFields(mask, 0);
}
// After computing all the fields, set the field state to `COMPUTED'.
setFieldsComputed(mask);
}
This computeFields implements the conversion from UTC
(millisecond offset from the Epoch) to calendar
field values. fieldMask specifies which fields to change the
setting state to COMPUTED, although all fields are set to
the correct values. This is required to fix 4685354.
Params: - fieldMask – a bit mask to specify which fields to change
the setting state.
- tzMask – a bit mask to specify which time zone offset
fields to be used for time calculations
Returns: a new field mask that indicates what field values have
actually been set.
/**
* This computeFields implements the conversion from UTC
* (millisecond offset from the Epoch) to calendar
* field values. fieldMask specifies which fields to change the
* setting state to COMPUTED, although all fields are set to
* the correct values. This is required to fix 4685354.
*
* @param fieldMask a bit mask to specify which fields to change
* the setting state.
* @param tzMask a bit mask to specify which time zone offset
* fields to be used for time calculations
* @return a new field mask that indicates what field values have
* actually been set.
*/
private int computeFields(int fieldMask, int tzMask) {
int zoneOffset = 0;
TimeZone tz = getZone();
if (zoneOffsets == null) {
zoneOffsets = new int[2];
}
if (tzMask != (ZONE_OFFSET_MASK|DST_OFFSET_MASK)) {
if (tz instanceof ZoneInfo) {
zoneOffset = ((ZoneInfo)tz).getOffsets(time, zoneOffsets);
} else {
zoneOffset = tz.getOffset(time);
zoneOffsets[0] = tz.getRawOffset();
zoneOffsets[1] = zoneOffset - zoneOffsets[0];
}
}
if (tzMask != 0) {
if (isFieldSet(tzMask, ZONE_OFFSET)) {
zoneOffsets[0] = internalGet(ZONE_OFFSET);
}
if (isFieldSet(tzMask, DST_OFFSET)) {
zoneOffsets[1] = internalGet(DST_OFFSET);
}
zoneOffset = zoneOffsets[0] + zoneOffsets[1];
}
// By computing time and zoneOffset separately, we can take
// the wider range of time+zoneOffset than the previous
// implementation.
long fixedDate = zoneOffset / ONE_DAY;
int timeOfDay = zoneOffset % (int)ONE_DAY;
fixedDate += time / ONE_DAY;
timeOfDay += (int) (time % ONE_DAY);
if (timeOfDay >= ONE_DAY) {
timeOfDay -= ONE_DAY;
++fixedDate;
} else {
while (timeOfDay < 0) {
timeOfDay += ONE_DAY;
--fixedDate;
}
}
fixedDate += EPOCH_OFFSET;
int era = CE;
int year;
if (fixedDate >= gregorianCutoverDate) {
// Handle Gregorian dates.
assert cachedFixedDate == Long.MIN_VALUE || gdate.isNormalized()
: "cache control: not normalized";
assert cachedFixedDate == Long.MIN_VALUE ||
gcal.getFixedDate(gdate.getNormalizedYear(),
gdate.getMonth(),
gdate.getDayOfMonth(), gdate)
== cachedFixedDate
: "cache control: inconsictency" +
", cachedFixedDate=" + cachedFixedDate +
", computed=" +
gcal.getFixedDate(gdate.getNormalizedYear(),
gdate.getMonth(),
gdate.getDayOfMonth(),
gdate) +
", date=" + gdate;
// See if we can use gdate to avoid date calculation.
if (fixedDate != cachedFixedDate) {
gcal.getCalendarDateFromFixedDate(gdate, fixedDate);
cachedFixedDate = fixedDate;
}
year = gdate.getYear();
if (year <= 0) {
year = 1 - year;
era = BCE;
}
calsys = gcal;
cdate = gdate;
assert cdate.getDayOfWeek() > 0 : "dow="+cdate.getDayOfWeek()+", date="+cdate;
} else {
// Handle Julian calendar dates.
calsys = getJulianCalendarSystem();
cdate = (BaseCalendar.Date) jcal.newCalendarDate(getZone());
jcal.getCalendarDateFromFixedDate(cdate, fixedDate);
Era e = cdate.getEra();
if (e == jeras[0]) {
era = BCE;
}
year = cdate.getYear();
}
// Always set the ERA and YEAR values.
internalSet(ERA, era);
internalSet(YEAR, year);
int mask = fieldMask | (ERA_MASK|YEAR_MASK);
int month = cdate.getMonth() - 1; // 0-based
int dayOfMonth = cdate.getDayOfMonth();
// Set the basic date fields.
if ((fieldMask & (MONTH_MASK|DAY_OF_MONTH_MASK|DAY_OF_WEEK_MASK))
!= 0) {
internalSet(MONTH, month);
internalSet(DAY_OF_MONTH, dayOfMonth);
internalSet(DAY_OF_WEEK, cdate.getDayOfWeek());
mask |= MONTH_MASK|DAY_OF_MONTH_MASK|DAY_OF_WEEK_MASK;
}
if ((fieldMask & (HOUR_OF_DAY_MASK|AM_PM_MASK|HOUR_MASK
|MINUTE_MASK|SECOND_MASK|MILLISECOND_MASK)) != 0) {
if (timeOfDay != 0) {
int hours = timeOfDay / ONE_HOUR;
internalSet(HOUR_OF_DAY, hours);
internalSet(AM_PM, hours / 12); // Assume AM == 0
internalSet(HOUR, hours % 12);
int r = timeOfDay % ONE_HOUR;
internalSet(MINUTE, r / ONE_MINUTE);
r %= ONE_MINUTE;
internalSet(SECOND, r / ONE_SECOND);
internalSet(MILLISECOND, r % ONE_SECOND);
} else {
internalSet(HOUR_OF_DAY, 0);
internalSet(AM_PM, AM);
internalSet(HOUR, 0);
internalSet(MINUTE, 0);
internalSet(SECOND, 0);
internalSet(MILLISECOND, 0);
}
mask |= (HOUR_OF_DAY_MASK|AM_PM_MASK|HOUR_MASK
|MINUTE_MASK|SECOND_MASK|MILLISECOND_MASK);
}
if ((fieldMask & (ZONE_OFFSET_MASK|DST_OFFSET_MASK)) != 0) {
internalSet(ZONE_OFFSET, zoneOffsets[0]);
internalSet(DST_OFFSET, zoneOffsets[1]);
mask |= (ZONE_OFFSET_MASK|DST_OFFSET_MASK);
}
if ((fieldMask & (DAY_OF_YEAR_MASK|WEEK_OF_YEAR_MASK|WEEK_OF_MONTH_MASK|DAY_OF_WEEK_IN_MONTH_MASK)) != 0) {
int normalizedYear = cdate.getNormalizedYear();
long fixedDateJan1 = calsys.getFixedDate(normalizedYear, 1, 1, cdate);
int dayOfYear = (int)(fixedDate - fixedDateJan1) + 1;
long fixedDateMonth1 = fixedDate - dayOfMonth + 1;
int cutoverGap = 0;
int cutoverYear = (calsys == gcal) ? gregorianCutoverYear : gregorianCutoverYearJulian;
int relativeDayOfMonth = dayOfMonth - 1;
// If we are in the cutover year, we need some special handling.
if (normalizedYear == cutoverYear) {
// Need to take care of the "missing" days.
if (gregorianCutoverYearJulian <= gregorianCutoverYear) {
// We need to find out where we are. The cutover
// gap could even be more than one year. (One
// year difference in ~48667 years.)
fixedDateJan1 = getFixedDateJan1(cdate, fixedDate);
if (fixedDate >= gregorianCutoverDate) {
fixedDateMonth1 = getFixedDateMonth1(cdate, fixedDate);
}
}
int realDayOfYear = (int)(fixedDate - fixedDateJan1) + 1;
cutoverGap = dayOfYear - realDayOfYear;
dayOfYear = realDayOfYear;
relativeDayOfMonth = (int)(fixedDate - fixedDateMonth1);
}
internalSet(DAY_OF_YEAR, dayOfYear);
internalSet(DAY_OF_WEEK_IN_MONTH, relativeDayOfMonth / 7 + 1);
int weekOfYear = getWeekNumber(fixedDateJan1, fixedDate);
// The spec is to calculate WEEK_OF_YEAR in the
// ISO8601-style. This creates problems, though.
if (weekOfYear == 0) {
// If the date belongs to the last week of the
// previous year, use the week number of "12/31" of
// the "previous" year. Again, if the previous year is
// the Gregorian cutover year, we need to take care of
// it. Usually the previous day of January 1 is
// December 31, which is not always true in
// GregorianCalendar.
long fixedDec31 = fixedDateJan1 - 1;
long prevJan1 = fixedDateJan1 - 365;
if (normalizedYear > (cutoverYear + 1)) {
if (CalendarUtils.isGregorianLeapYear(normalizedYear - 1)) {
--prevJan1;
}
} else if (normalizedYear <= gregorianCutoverYearJulian) {
if (CalendarUtils.isJulianLeapYear(normalizedYear - 1)) {
--prevJan1;
}
} else {
BaseCalendar calForJan1 = calsys;
//int prevYear = normalizedYear - 1;
int prevYear = getCalendarDate(fixedDec31).getNormalizedYear();
if (prevYear == gregorianCutoverYear) {
calForJan1 = getCutoverCalendarSystem();
if (calForJan1 == jcal) {
prevJan1 = calForJan1.getFixedDate(prevYear,
BaseCalendar.JANUARY,
1,
null);
} else {
prevJan1 = gregorianCutoverDate;
calForJan1 = gcal;
}
} else if (prevYear <= gregorianCutoverYearJulian) {
calForJan1 = getJulianCalendarSystem();
prevJan1 = calForJan1.getFixedDate(prevYear,
BaseCalendar.JANUARY,
1,
null);
}
}
weekOfYear = getWeekNumber(prevJan1, fixedDec31);
} else {
if (normalizedYear > gregorianCutoverYear ||
normalizedYear < (gregorianCutoverYearJulian - 1)) {
// Regular years
if (weekOfYear >= 52) {
long nextJan1 = fixedDateJan1 + 365;
if (cdate.isLeapYear()) {
nextJan1++;
}
long nextJan1st = BaseCalendar.getDayOfWeekDateOnOrBefore(nextJan1 + 6,
getFirstDayOfWeek());
int ndays = (int)(nextJan1st - nextJan1);
if (ndays >= getMinimalDaysInFirstWeek() && fixedDate >= (nextJan1st - 7)) {
// The first days forms a week in which the date is included.
weekOfYear = 1;
}
}
} else {
BaseCalendar calForJan1 = calsys;
int nextYear = normalizedYear + 1;
if (nextYear == (gregorianCutoverYearJulian + 1) &&
nextYear < gregorianCutoverYear) {
// In case the gap is more than one year.
nextYear = gregorianCutoverYear;
}
if (nextYear == gregorianCutoverYear) {
calForJan1 = getCutoverCalendarSystem();
}
long nextJan1;
if (nextYear > gregorianCutoverYear
|| gregorianCutoverYearJulian == gregorianCutoverYear
|| nextYear == gregorianCutoverYearJulian) {
nextJan1 = calForJan1.getFixedDate(nextYear,
BaseCalendar.JANUARY,
1,
null);
} else {
nextJan1 = gregorianCutoverDate;
calForJan1 = gcal;
}
long nextJan1st = BaseCalendar.getDayOfWeekDateOnOrBefore(nextJan1 + 6,
getFirstDayOfWeek());
int ndays = (int)(nextJan1st - nextJan1);
if (ndays >= getMinimalDaysInFirstWeek() && fixedDate >= (nextJan1st - 7)) {
// The first days forms a week in which the date is included.
weekOfYear = 1;
}
}
}
internalSet(WEEK_OF_YEAR, weekOfYear);
internalSet(WEEK_OF_MONTH, getWeekNumber(fixedDateMonth1, fixedDate));
mask |= (DAY_OF_YEAR_MASK|WEEK_OF_YEAR_MASK|WEEK_OF_MONTH_MASK|DAY_OF_WEEK_IN_MONTH_MASK);
}
return mask;
}
Returns the number of weeks in a period between fixedDay1 and
fixedDate. The getFirstDayOfWeek-getMinimalDaysInFirstWeek rule
is applied to calculate the number of weeks.
Params: - fixedDay1 – the fixed date of the first day of the period
- fixedDate – the fixed date of the last day of the period
Returns: the number of weeks of the given period
/**
* Returns the number of weeks in a period between fixedDay1 and
* fixedDate. The getFirstDayOfWeek-getMinimalDaysInFirstWeek rule
* is applied to calculate the number of weeks.
*
* @param fixedDay1 the fixed date of the first day of the period
* @param fixedDate the fixed date of the last day of the period
* @return the number of weeks of the given period
*/
private int getWeekNumber(long fixedDay1, long fixedDate) {
// We can always use `gcal' since Julian and Gregorian are the
// same thing for this calculation.
long fixedDay1st = Gregorian.getDayOfWeekDateOnOrBefore(fixedDay1 + 6,
getFirstDayOfWeek());
int ndays = (int)(fixedDay1st - fixedDay1);
assert ndays <= 7;
if (ndays >= getMinimalDaysInFirstWeek()) {
fixedDay1st -= 7;
}
int normalizedDayOfPeriod = (int)(fixedDate - fixedDay1st);
if (normalizedDayOfPeriod >= 0) {
return normalizedDayOfPeriod / 7 + 1;
}
return CalendarUtils.floorDivide(normalizedDayOfPeriod, 7) + 1;
}
Converts calendar field values to the time value (millisecond
offset from the Epoch).
Throws: - IllegalArgumentException – if any calendar fields are invalid.
/**
* Converts calendar field values to the time value (millisecond
* offset from the <a href="Calendar.html#Epoch">Epoch</a>).
*
* @throws IllegalArgumentException if any calendar fields are invalid.
*/
@Override
protected void computeTime() {
// In non-lenient mode, perform brief checking of calendar
// fields which have been set externally. Through this
// checking, the field values are stored in originalFields[]
// to see if any of them are normalized later.
if (!isLenient()) {
if (originalFields == null) {
originalFields = new int[FIELD_COUNT];
}
for (int field = 0; field < FIELD_COUNT; field++) {
int value = internalGet(field);
if (isExternallySet(field)) {
// Quick validation for any out of range values
if (value < getMinimum(field) || value > getMaximum(field)) {
throw new IllegalArgumentException(getFieldName(field));
}
}
originalFields[field] = value;
}
}
// Let the super class determine which calendar fields to be
// used to calculate the time.
int fieldMask = selectFields();
// The year defaults to the epoch start. We don't check
// fieldMask for YEAR because YEAR is a mandatory field to
// determine the date.
int year = isSet(YEAR) ? internalGet(YEAR) : EPOCH_YEAR;
int era = internalGetEra();
if (era == BCE) {
year = 1 - year;
} else if (era != CE) {
// Even in lenient mode we disallow ERA values other than CE & BCE.
// (The same normalization rule as add()/roll() could be
// applied here in lenient mode. But this checking is kept
// unchanged for compatibility as of 1.5.)
throw new IllegalArgumentException("Invalid era");
}
// If year is 0 or negative, we need to set the ERA value later.
if (year <= 0 && !isSet(ERA)) {
fieldMask |= ERA_MASK;
setFieldsComputed(ERA_MASK);
}
// Calculate the time of day. We rely on the convention that
// an UNSET field has 0.
long timeOfDay = 0;
if (isFieldSet(fieldMask, HOUR_OF_DAY)) {
timeOfDay += (long) internalGet(HOUR_OF_DAY);
} else {
timeOfDay += internalGet(HOUR);
// The default value of AM_PM is 0 which designates AM.
if (isFieldSet(fieldMask, AM_PM)) {
timeOfDay += 12 * internalGet(AM_PM);
}
}
timeOfDay *= 60;
timeOfDay += internalGet(MINUTE);
timeOfDay *= 60;
timeOfDay += internalGet(SECOND);
timeOfDay *= 1000;
timeOfDay += internalGet(MILLISECOND);
// Convert the time of day to the number of days and the
// millisecond offset from midnight.
long fixedDate = timeOfDay / ONE_DAY;
timeOfDay %= ONE_DAY;
while (timeOfDay < 0) {
timeOfDay += ONE_DAY;
--fixedDate;
}
// Calculate the fixed date since January 1, 1 (Gregorian).
calculateFixedDate: {
long gfd, jfd;
if (year > gregorianCutoverYear && year > gregorianCutoverYearJulian) {
gfd = fixedDate + getFixedDate(gcal, year, fieldMask);
if (gfd >= gregorianCutoverDate) {
fixedDate = gfd;
break calculateFixedDate;
}
jfd = fixedDate + getFixedDate(getJulianCalendarSystem(), year, fieldMask);
} else if (year < gregorianCutoverYear && year < gregorianCutoverYearJulian) {
jfd = fixedDate + getFixedDate(getJulianCalendarSystem(), year, fieldMask);
if (jfd < gregorianCutoverDate) {
fixedDate = jfd;
break calculateFixedDate;
}
gfd = jfd;
} else {
jfd = fixedDate + getFixedDate(getJulianCalendarSystem(), year, fieldMask);
gfd = fixedDate + getFixedDate(gcal, year, fieldMask);
}
// Now we have to determine which calendar date it is.
// If the date is relative from the beginning of the year
// in the Julian calendar, then use jfd;
if (isFieldSet(fieldMask, DAY_OF_YEAR) || isFieldSet(fieldMask, WEEK_OF_YEAR)) {
if (gregorianCutoverYear == gregorianCutoverYearJulian) {
fixedDate = jfd;
break calculateFixedDate;
} else if (year == gregorianCutoverYear) {
fixedDate = gfd;
break calculateFixedDate;
}
}
if (gfd >= gregorianCutoverDate) {
if (jfd >= gregorianCutoverDate) {
fixedDate = gfd;
} else {
// The date is in an "overlapping" period. No way
// to disambiguate it. Determine it using the
// previous date calculation.
if (calsys == gcal || calsys == null) {
fixedDate = gfd;
} else {
fixedDate = jfd;
}
}
} else {
if (jfd < gregorianCutoverDate) {
fixedDate = jfd;
} else {
// The date is in a "missing" period.
if (!isLenient()) {
throw new IllegalArgumentException("the specified date doesn't exist");
}
// Take the Julian date for compatibility, which
// will produce a Gregorian date.
fixedDate = jfd;
}
}
}
// millis represents local wall-clock time in milliseconds.
long millis = (fixedDate - EPOCH_OFFSET) * ONE_DAY + timeOfDay;
// Compute the time zone offset and DST offset. There are two potential
// ambiguities here. We'll assume a 2:00 am (wall time) switchover time
// for discussion purposes here.
// 1. The transition into DST. Here, a designated time of 2:00 am - 2:59 am
// can be in standard or in DST depending. However, 2:00 am is an invalid
// representation (the representation jumps from 1:59:59 am Std to 3:00:00 am DST).
// We assume standard time.
// 2. The transition out of DST. Here, a designated time of 1:00 am - 1:59 am
// can be in standard or DST. Both are valid representations (the rep
// jumps from 1:59:59 DST to 1:00:00 Std).
// Again, we assume standard time.
// We use the TimeZone object, unless the user has explicitly set the ZONE_OFFSET
// or DST_OFFSET fields; then we use those fields.
TimeZone zone = getZone();
if (zoneOffsets == null) {
zoneOffsets = new int[2];
}
int tzMask = fieldMask & (ZONE_OFFSET_MASK|DST_OFFSET_MASK);
if (tzMask != (ZONE_OFFSET_MASK|DST_OFFSET_MASK)) {
if (zone instanceof ZoneInfo) {
((ZoneInfo)zone).getOffsetsByWall(millis, zoneOffsets);
} else {
int gmtOffset = isFieldSet(fieldMask, ZONE_OFFSET) ?
internalGet(ZONE_OFFSET) : zone.getRawOffset();
zone.getOffsets(millis - gmtOffset, zoneOffsets);
}
}
if (tzMask != 0) {
if (isFieldSet(tzMask, ZONE_OFFSET)) {
zoneOffsets[0] = internalGet(ZONE_OFFSET);
}
if (isFieldSet(tzMask, DST_OFFSET)) {
zoneOffsets[1] = internalGet(DST_OFFSET);
}
}
// Adjust the time zone offset values to get the UTC time.
millis -= zoneOffsets[0] + zoneOffsets[1];
// Set this calendar's time in milliseconds
time = millis;
int mask = computeFields(fieldMask | getSetStateFields(), tzMask);
if (!isLenient()) {
for (int field = 0; field < FIELD_COUNT; field++) {
if (!isExternallySet(field)) {
continue;
}
if (originalFields[field] != internalGet(field)) {
String s = originalFields[field] + " -> " + internalGet(field);
// Restore the original field values
System.arraycopy(originalFields, 0, fields, 0, fields.length);
throw new IllegalArgumentException(getFieldName(field) + ": " + s);
}
}
}
setFieldsNormalized(mask);
}
Computes the fixed date under either the Gregorian or the
Julian calendar, using the given year and the specified calendar fields.
Params: - cal – the CalendarSystem to be used for the date calculation
- year – the normalized year number, with 0 indicating the
year 1 BCE, -1 indicating 2 BCE, etc.
- fieldMask – the calendar fields to be used for the date calculation
See Also: Returns: the fixed date
/**
* Computes the fixed date under either the Gregorian or the
* Julian calendar, using the given year and the specified calendar fields.
*
* @param cal the CalendarSystem to be used for the date calculation
* @param year the normalized year number, with 0 indicating the
* year 1 BCE, -1 indicating 2 BCE, etc.
* @param fieldMask the calendar fields to be used for the date calculation
* @return the fixed date
* @see Calendar#selectFields
*/
private long getFixedDate(BaseCalendar cal, int year, int fieldMask) {
int month = JANUARY;
if (isFieldSet(fieldMask, MONTH)) {
// No need to check if MONTH has been set (no isSet(MONTH)
// call) since its unset value happens to be JANUARY (0).
month = internalGet(MONTH);
// If the month is out of range, adjust it into range
if (month > DECEMBER) {
year += month / 12;
month %= 12;
} else if (month < JANUARY) {
int[] rem = new int[1];
year += CalendarUtils.floorDivide(month, 12, rem);
month = rem[0];
}
}
// Get the fixed date since Jan 1, 1 (Gregorian). We are on
// the first day of either `month' or January in 'year'.
long fixedDate = cal.getFixedDate(year, month + 1, 1,
cal == gcal ? gdate : null);
if (isFieldSet(fieldMask, MONTH)) {
// Month-based calculations
if (isFieldSet(fieldMask, DAY_OF_MONTH)) {
// We are on the first day of the month. Just add the
// offset if DAY_OF_MONTH is set. If the isSet call
// returns false, that means DAY_OF_MONTH has been
// selected just because of the selected
// combination. We don't need to add any since the
// default value is the 1st.
if (isSet(DAY_OF_MONTH)) {
// To avoid underflow with DAY_OF_MONTH-1, add
// DAY_OF_MONTH, then subtract 1.
fixedDate += internalGet(DAY_OF_MONTH);
fixedDate--;
}
} else {
if (isFieldSet(fieldMask, WEEK_OF_MONTH)) {
long firstDayOfWeek = BaseCalendar.getDayOfWeekDateOnOrBefore(fixedDate + 6,
getFirstDayOfWeek());
// If we have enough days in the first week, then
// move to the previous week.
if ((firstDayOfWeek - fixedDate) >= getMinimalDaysInFirstWeek()) {
firstDayOfWeek -= 7;
}
if (isFieldSet(fieldMask, DAY_OF_WEEK)) {
firstDayOfWeek = BaseCalendar.getDayOfWeekDateOnOrBefore(firstDayOfWeek + 6,
internalGet(DAY_OF_WEEK));
}
// In lenient mode, we treat days of the previous
// months as a part of the specified
// WEEK_OF_MONTH. See 4633646.
fixedDate = firstDayOfWeek + 7 * (internalGet(WEEK_OF_MONTH) - 1);
} else {
int dayOfWeek;
if (isFieldSet(fieldMask, DAY_OF_WEEK)) {
dayOfWeek = internalGet(DAY_OF_WEEK);
} else {
dayOfWeek = getFirstDayOfWeek();
}
// We are basing this on the day-of-week-in-month. The only
// trickiness occurs if the day-of-week-in-month is
// negative.
int dowim;
if (isFieldSet(fieldMask, DAY_OF_WEEK_IN_MONTH)) {
dowim = internalGet(DAY_OF_WEEK_IN_MONTH);
} else {
dowim = 1;
}
if (dowim >= 0) {
fixedDate = BaseCalendar.getDayOfWeekDateOnOrBefore(fixedDate + (7 * dowim) - 1,
dayOfWeek);
} else {
// Go to the first day of the next week of
// the specified week boundary.
int lastDate = monthLength(month, year) + (7 * (dowim + 1));
// Then, get the day of week date on or before the last date.
fixedDate = BaseCalendar.getDayOfWeekDateOnOrBefore(fixedDate + lastDate - 1,
dayOfWeek);
}
}
}
} else {
if (year == gregorianCutoverYear && cal == gcal
&& fixedDate < gregorianCutoverDate
&& gregorianCutoverYear != gregorianCutoverYearJulian) {
// January 1 of the year doesn't exist. Use
// gregorianCutoverDate as the first day of the
// year.
fixedDate = gregorianCutoverDate;
}
// We are on the first day of the year.
if (isFieldSet(fieldMask, DAY_OF_YEAR)) {
// Add the offset, then subtract 1. (Make sure to avoid underflow.)
fixedDate += internalGet(DAY_OF_YEAR);
fixedDate--;
} else {
long firstDayOfWeek = BaseCalendar.getDayOfWeekDateOnOrBefore(fixedDate + 6,
getFirstDayOfWeek());
// If we have enough days in the first week, then move
// to the previous week.
if ((firstDayOfWeek - fixedDate) >= getMinimalDaysInFirstWeek()) {
firstDayOfWeek -= 7;
}
if (isFieldSet(fieldMask, DAY_OF_WEEK)) {
int dayOfWeek = internalGet(DAY_OF_WEEK);
if (dayOfWeek != getFirstDayOfWeek()) {
firstDayOfWeek = BaseCalendar.getDayOfWeekDateOnOrBefore(firstDayOfWeek + 6,
dayOfWeek);
}
}
fixedDate = firstDayOfWeek + 7 * ((long)internalGet(WEEK_OF_YEAR) - 1);
}
}
return fixedDate;
}
Returns this object if it's normalized (all fields and time are
in sync). Otherwise, a cloned object is returned after calling
complete() in lenient mode.
/**
* Returns this object if it's normalized (all fields and time are
* in sync). Otherwise, a cloned object is returned after calling
* complete() in lenient mode.
*/
private GregorianCalendar getNormalizedCalendar() {
GregorianCalendar gc;
if (isFullyNormalized()) {
gc = this;
} else {
// Create a clone and normalize the calendar fields
gc = (GregorianCalendar) this.clone();
gc.setLenient(true);
gc.complete();
}
return gc;
}
Returns the Julian calendar system instance (singleton). 'jcal'
and 'jeras' are set upon the return.
/**
* Returns the Julian calendar system instance (singleton). 'jcal'
* and 'jeras' are set upon the return.
*/
private static synchronized BaseCalendar getJulianCalendarSystem() {
if (jcal == null) {
jcal = (JulianCalendar) CalendarSystem.forName("julian");
jeras = jcal.getEras();
}
return jcal;
}
Returns the calendar system for dates before the cutover date
in the cutover year. If the cutover date is January 1, the
method returns Gregorian. Otherwise, Julian.
/**
* Returns the calendar system for dates before the cutover date
* in the cutover year. If the cutover date is January 1, the
* method returns Gregorian. Otherwise, Julian.
*/
private BaseCalendar getCutoverCalendarSystem() {
if (gregorianCutoverYearJulian < gregorianCutoverYear) {
return gcal;
}
return getJulianCalendarSystem();
}
Determines if the specified year (normalized) is the Gregorian
cutover year. This object must have been normalized.
/**
* Determines if the specified year (normalized) is the Gregorian
* cutover year. This object must have been normalized.
*/
private boolean isCutoverYear(int normalizedYear) {
int cutoverYear = (calsys == gcal) ? gregorianCutoverYear : gregorianCutoverYearJulian;
return normalizedYear == cutoverYear;
}
Returns the fixed date of the first day of the year (usually
January 1) before the specified date.
Params: - date – the date for which the first day of the year is
calculated. The date has to be in the cut-over year (Gregorian
or Julian).
- fixedDate – the fixed date representation of the date
/**
* Returns the fixed date of the first day of the year (usually
* January 1) before the specified date.
*
* @param date the date for which the first day of the year is
* calculated. The date has to be in the cut-over year (Gregorian
* or Julian).
* @param fixedDate the fixed date representation of the date
*/
private long getFixedDateJan1(BaseCalendar.Date date, long fixedDate) {
assert date.getNormalizedYear() == gregorianCutoverYear ||
date.getNormalizedYear() == gregorianCutoverYearJulian;
if (gregorianCutoverYear != gregorianCutoverYearJulian) {
if (fixedDate >= gregorianCutoverDate) {
// Dates before the cutover date don't exist
// in the same (Gregorian) year. So, no
// January 1 exists in the year. Use the
// cutover date as the first day of the year.
return gregorianCutoverDate;
}
}
// January 1 of the normalized year should exist.
BaseCalendar juliancal = getJulianCalendarSystem();
return juliancal.getFixedDate(date.getNormalizedYear(), BaseCalendar.JANUARY, 1, null);
}
Returns the fixed date of the first date of the month (usually
the 1st of the month) before the specified date.
Params: - date – the date for which the first day of the month is
calculated. The date has to be in the cut-over year (Gregorian
or Julian).
- fixedDate – the fixed date representation of the date
/**
* Returns the fixed date of the first date of the month (usually
* the 1st of the month) before the specified date.
*
* @param date the date for which the first day of the month is
* calculated. The date has to be in the cut-over year (Gregorian
* or Julian).
* @param fixedDate the fixed date representation of the date
*/
private long getFixedDateMonth1(BaseCalendar.Date date, long fixedDate) {
assert date.getNormalizedYear() == gregorianCutoverYear ||
date.getNormalizedYear() == gregorianCutoverYearJulian;
BaseCalendar.Date gCutover = getGregorianCutoverDate();
if (gCutover.getMonth() == BaseCalendar.JANUARY
&& gCutover.getDayOfMonth() == 1) {
// The cutover happened on January 1.
return fixedDate - date.getDayOfMonth() + 1;
}
long fixedDateMonth1;
// The cutover happened sometime during the year.
if (date.getMonth() == gCutover.getMonth()) {
// The cutover happened in the month.
BaseCalendar.Date jLastDate = getLastJulianDate();
if (gregorianCutoverYear == gregorianCutoverYearJulian
&& gCutover.getMonth() == jLastDate.getMonth()) {
// The "gap" fits in the same month.
fixedDateMonth1 = jcal.getFixedDate(date.getNormalizedYear(),
date.getMonth(),
1,
null);
} else {
// Use the cutover date as the first day of the month.
fixedDateMonth1 = gregorianCutoverDate;
}
} else {
// The cutover happened before the month.
fixedDateMonth1 = fixedDate - date.getDayOfMonth() + 1;
}
return fixedDateMonth1;
}
Returns a CalendarDate produced from the specified fixed date.
Params: - fd – the fixed date
/**
* Returns a CalendarDate produced from the specified fixed date.
*
* @param fd the fixed date
*/
private BaseCalendar.Date getCalendarDate(long fd) {
BaseCalendar cal = (fd >= gregorianCutoverDate) ? gcal : getJulianCalendarSystem();
BaseCalendar.Date d = (BaseCalendar.Date) cal.newCalendarDate(TimeZone.NO_TIMEZONE);
cal.getCalendarDateFromFixedDate(d, fd);
return d;
}
Returns the Gregorian cutover date as a BaseCalendar.Date. The
date is a Gregorian date.
/**
* Returns the Gregorian cutover date as a BaseCalendar.Date. The
* date is a Gregorian date.
*/
private BaseCalendar.Date getGregorianCutoverDate() {
return getCalendarDate(gregorianCutoverDate);
}
Returns the day before the Gregorian cutover date as a
BaseCalendar.Date. The date is a Julian date.
/**
* Returns the day before the Gregorian cutover date as a
* BaseCalendar.Date. The date is a Julian date.
*/
private BaseCalendar.Date getLastJulianDate() {
return getCalendarDate(gregorianCutoverDate - 1);
}
Returns the length of the specified month in the specified
year. The year number must be normalized.
See Also: - isLeapYear(int)
/**
* Returns the length of the specified month in the specified
* year. The year number must be normalized.
*
* @see #isLeapYear(int)
*/
private int monthLength(int month, int year) {
return isLeapYear(year) ? LEAP_MONTH_LENGTH[month] : MONTH_LENGTH[month];
}
Returns the length of the specified month in the year provided
by internalGet(YEAR).
See Also: - isLeapYear(int)
/**
* Returns the length of the specified month in the year provided
* by internalGet(YEAR).
*
* @see #isLeapYear(int)
*/
private int monthLength(int month) {
int year = internalGet(YEAR);
if (internalGetEra() == BCE) {
year = 1 - year;
}
return monthLength(month, year);
}
private int actualMonthLength() {
int year = cdate.getNormalizedYear();
if (year != gregorianCutoverYear && year != gregorianCutoverYearJulian) {
return calsys.getMonthLength(cdate);
}
BaseCalendar.Date date = (BaseCalendar.Date) cdate.clone();
long fd = calsys.getFixedDate(date);
long month1 = getFixedDateMonth1(date, fd);
long next1 = month1 + calsys.getMonthLength(date);
if (next1 < gregorianCutoverDate) {
return (int)(next1 - month1);
}
if (cdate != gdate) {
date = (BaseCalendar.Date) gcal.newCalendarDate(TimeZone.NO_TIMEZONE);
}
gcal.getCalendarDateFromFixedDate(date, next1);
next1 = getFixedDateMonth1(date, next1);
return (int)(next1 - month1);
}
Returns the length (in days) of the specified year. The year
must be normalized.
/**
* Returns the length (in days) of the specified year. The year
* must be normalized.
*/
private int yearLength(int year) {
return isLeapYear(year) ? 366 : 365;
}
Returns the length (in days) of the year provided by
internalGet(YEAR).
/**
* Returns the length (in days) of the year provided by
* internalGet(YEAR).
*/
private int yearLength() {
int year = internalGet(YEAR);
if (internalGetEra() == BCE) {
year = 1 - year;
}
return yearLength(year);
}
After adjustments such as add(MONTH), add(YEAR), we don't want the
month to jump around. E.g., we don't want Jan 31 + 1 month to go to Mar
3, we want it to go to Feb 28. Adjustments which might run into this
problem call this method to retain the proper month.
/**
* After adjustments such as add(MONTH), add(YEAR), we don't want the
* month to jump around. E.g., we don't want Jan 31 + 1 month to go to Mar
* 3, we want it to go to Feb 28. Adjustments which might run into this
* problem call this method to retain the proper month.
*/
private void pinDayOfMonth() {
int year = internalGet(YEAR);
int monthLen;
if (year > gregorianCutoverYear || year < gregorianCutoverYearJulian) {
monthLen = monthLength(internalGet(MONTH));
} else {
GregorianCalendar gc = getNormalizedCalendar();
monthLen = gc.getActualMaximum(DAY_OF_MONTH);
}
int dom = internalGet(DAY_OF_MONTH);
if (dom > monthLen) {
set(DAY_OF_MONTH, monthLen);
}
}
Returns the fixed date value of this object. The time value and
calendar fields must be in synch.
/**
* Returns the fixed date value of this object. The time value and
* calendar fields must be in synch.
*/
private long getCurrentFixedDate() {
return (calsys == gcal) ? cachedFixedDate : calsys.getFixedDate(cdate);
}
Returns the new value after 'roll'ing the specified value and amount.
/**
* Returns the new value after 'roll'ing the specified value and amount.
*/
private static int getRolledValue(int value, int amount, int min, int max) {
assert value >= min && value <= max;
int range = max - min + 1;
amount %= range;
int n = value + amount;
if (n > max) {
n -= range;
} else if (n < min) {
n += range;
}
assert n >= min && n <= max;
return n;
}
Returns the ERA. We need a special method for this because the
default ERA is CE, but a zero (unset) ERA is BCE.
/**
* Returns the ERA. We need a special method for this because the
* default ERA is CE, but a zero (unset) ERA is BCE.
*/
private int internalGetEra() {
return isSet(ERA) ? internalGet(ERA) : CE;
}
Updates internal state.
/**
* Updates internal state.
*/
@java.io.Serial
private void readObject(ObjectInputStream stream)
throws IOException, ClassNotFoundException {
stream.defaultReadObject();
if (gdate == null) {
gdate = (BaseCalendar.Date) gcal.newCalendarDate(getZone());
cachedFixedDate = Long.MIN_VALUE;
}
setGregorianChange(gregorianCutover);
}
Converts this object to a ZonedDateTime that represents the same point on the time-line as this GregorianCalendar. Since this object supports a Julian-Gregorian cutover date and ZonedDateTime does not, it is possible that the resulting year, month and day will have different values. The result will represent the correct date in the ISO calendar system, which will also be the same value for Modified Julian Days.
Returns: a zoned date-time representing the same point on the time-line
as this gregorian calendar Since: 1.8
/**
* Converts this object to a {@code ZonedDateTime} that represents
* the same point on the time-line as this {@code GregorianCalendar}.
* <p>
* Since this object supports a Julian-Gregorian cutover date and
* {@code ZonedDateTime} does not, it is possible that the resulting year,
* month and day will have different values. The result will represent the
* correct date in the ISO calendar system, which will also be the same value
* for Modified Julian Days.
*
* @return a zoned date-time representing the same point on the time-line
* as this gregorian calendar
* @since 1.8
*/
public ZonedDateTime toZonedDateTime() {
return ZonedDateTime.ofInstant(Instant.ofEpochMilli(getTimeInMillis()),
getTimeZone().toZoneId());
}
Obtains an instance of GregorianCalendar with the default locale from a ZonedDateTime object. Since ZonedDateTime does not support a Julian-Gregorian cutover date and uses ISO calendar system, the return GregorianCalendar is a pure Gregorian calendar and uses ISO 8601 standard for week definitions, which has MONDAY as the
FirstDayOfWeek and 4 as the value of the MinimalDaysInFirstWeek.
ZoneDateTime can store points on the time-line further in the future and further in the past than GregorianCalendar. In this scenario, this method will throw an IllegalArgumentException exception.
Params: - zdt – the zoned date-time object to convert
Throws: - NullPointerException – if
zdt is null - IllegalArgumentException – if the zoned date-time is too large to represent as a
GregorianCalendar
Returns: the gregorian calendar representing the same point on the
time-line as the zoned date-time provided Since: 1.8
/**
* Obtains an instance of {@code GregorianCalendar} with the default locale
* from a {@code ZonedDateTime} object.
* <p>
* Since {@code ZonedDateTime} does not support a Julian-Gregorian cutover
* date and uses ISO calendar system, the return GregorianCalendar is a pure
* Gregorian calendar and uses ISO 8601 standard for week definitions,
* which has {@code MONDAY} as the {@link Calendar#getFirstDayOfWeek()
* FirstDayOfWeek} and {@code 4} as the value of the
* {@link Calendar#getMinimalDaysInFirstWeek() MinimalDaysInFirstWeek}.
* <p>
* {@code ZoneDateTime} can store points on the time-line further in the
* future and further in the past than {@code GregorianCalendar}. In this
* scenario, this method will throw an {@code IllegalArgumentException}
* exception.
*
* @param zdt the zoned date-time object to convert
* @return the gregorian calendar representing the same point on the
* time-line as the zoned date-time provided
* @throws NullPointerException if {@code zdt} is null
* @throws IllegalArgumentException if the zoned date-time is too
* large to represent as a {@code GregorianCalendar}
* @since 1.8
*/
public static GregorianCalendar from(ZonedDateTime zdt) {
GregorianCalendar cal = new GregorianCalendar(TimeZone.getTimeZone(zdt.getZone()));
cal.setGregorianChange(new Date(Long.MIN_VALUE));
cal.setFirstDayOfWeek(MONDAY);
cal.setMinimalDaysInFirstWeek(4);
try {
cal.setTimeInMillis(Math.addExact(Math.multiplyExact(zdt.toEpochSecond(), 1000),
zdt.get(ChronoField.MILLI_OF_SECOND)));
} catch (ArithmeticException ex) {
throw new IllegalArgumentException(ex);
}
return cal;
}
}