java.util.GregorianCalendar Maven / Gradle / Ivy
/*
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership.
* The ASF licenses this file to You under the Apache License, Version 2.0
* (the "License"); you may not use this file except in compliance with
* the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package java.util;
import java.io.IOException;
import java.io.ObjectInputStream;
import java.io.ObjectOutputStream;
/**
* {@code GregorianCalendar} is a concrete subclass of {@link Calendar}
* and provides the standard calendar used by most of the world.
*
*
* The standard (Gregorian) calendar has 2 eras, BC and AD.
*
*
* This implementation handles a single discontinuity, which corresponds by
* default to the date 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 {@code setGregorianChange()}.
*
*
* Historically, in those countries which adopted the Gregorian calendar first,
* October 4, 1582 was thus followed by October 15, 1582. 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.
*
*
* {@code 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,
* {@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.
*
*
* 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.
*
*
* Values calculated for the {@code WEEK_OF_YEAR} field range from 1 to
* 53. Week 1 for a year is the earliest seven day period starting on
* {@code getFirstDayOfWeek()} that contains at least
* {@code 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 are
* numbered sequentially from 2 to 52 or 53 (as needed).
*
*
* For example, January 1, 1998 was a Thursday. If
* {@code getFirstDayOfWeek()} is {@code MONDAY} and
* {@code getMinimalDaysInFirstWeek()} is 4 (these are the values
* reflecting ISO 8601 and many national standards), then week 1 of 1998 starts
* on December 29, 1997, and ends on January 4, 1998. 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.
*
*
* Values calculated for the {@code WEEK_OF_MONTH} field range from 0 or
* 1 to 4 or 5. Week 1 of a month (the days with WEEK_OF_MONTH =
* 1)
* 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.
*
*
* 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.
*
*
* 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 savings 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
*
*
*
*
* @see Calendar
* @see TimeZone
*/
public class GregorianCalendar extends Calendar {
/**
* Value for the BC era.
*/
public static final int BC = 0;
/**
* Value for the AD era.
*/
public static final int AD = 1;
private static final long defaultGregorianCutover = -12219292800000l;
private long gregorianCutover = defaultGregorianCutover;
private transient int changeYear = 1582;
private transient int julianSkew = ((changeYear - 2000) / 400)
+ julianError() - ((changeYear - 2000) / 100);
static byte[] DaysInMonth = new byte[]{31, 28, 31, 30, 31, 30, 31, 31,
30, 31, 30, 31};
private static int[] DaysInYear = new int[]{0, 31, 59, 90, 120, 151, 181,
212, 243, 273, 304, 334};
private static int[] maximums = new int[]{1, 292278994, 11, 53, 6, 31,
366, 7, 6, 1, 11, 23, 59, 59, 999, 14 * 3600 * 1000, 7200000};
private static int[] minimums = new int[]{0, 1, 0, 1, 0, 1, 1, 1, 1, 0,
0, 0, 0, 0, 0, -13 * 3600 * 1000, 0};
private static int[] leastMaximums = new int[]{1, 292269054, 11, 50, 3,
28, 355, 7, 3, 1, 11, 23, 59, 59, 999, 50400000, 1200000};
private int currentYearSkew = 10;
private int lastYearSkew = 0;
/**
* Constructs a new {@code GregorianCalendar} initialized to the current date and
* time with the default {@code Locale} and {@code TimeZone}.
*/
public GregorianCalendar() {
this(TimeZone.getDefault(), Locale.getDefault());
}
/**
* Constructs a new {@code GregorianCalendar} initialized to midnight in the default
* {@code TimeZone} and {@code Locale} on the specified date.
*
* @param year the year.
* @param month the month.
* @param day the day of the month.
*/
public GregorianCalendar(int year, int month, int day) {
super(TimeZone.getDefault(), Locale.getDefault());
set(year, month, day);
}
/**
* Constructs a new {@code GregorianCalendar} initialized to the specified date and
* time in the default {@code TimeZone} and {@code Locale}.
*
* @param year the year.
* @param month the month.
* @param day the day of the month.
* @param hour the hour.
* @param minute the minute.
*/
public GregorianCalendar(int year, int month, int day, int hour, int minute) {
super(TimeZone.getDefault(), Locale.getDefault());
set(year, month, day, hour, minute);
}
/**
* Constructs a new {@code GregorianCalendar} initialized to the specified date and
* time in the default {@code TimeZone} and {@code Locale}.
*
* @param year the year.
* @param month the month.
* @param day the day of the month.
* @param hour the hour.
* @param minute the minute.
* @param second the second.
*/
public GregorianCalendar(int year, int month, int day, int hour,
int minute, int second) {
super(TimeZone.getDefault(), Locale.getDefault());
set(year, month, day, hour, minute, second);
}
GregorianCalendar(long milliseconds) {
this(false);
setTimeInMillis(milliseconds);
}
/**
* Constructs a new {@code GregorianCalendar} initialized to the current date and
* time and using the specified {@code Locale} and the default {@code TimeZone}.
*
* @param locale the {@code Locale}.
*/
public GregorianCalendar(Locale locale) {
this(TimeZone.getDefault(), locale);
}
/**
* Constructs a new {@code GregorianCalendar} initialized to the current date and
* time and using the specified {@code TimeZone} and the default {@code Locale}.
*
* @param timezone the {@code TimeZone}.
*/
public GregorianCalendar(TimeZone timezone) {
this(timezone, Locale.getDefault());
}
/**
* Constructs a new {@code GregorianCalendar} initialized to the current date and
* time and using the specified {@code TimeZone} and {@code Locale}.
*
* @param timezone the {@code TimeZone}.
* @param locale the {@code Locale}.
*/
public GregorianCalendar(TimeZone timezone, Locale locale) {
super(timezone, locale);
setTimeInMillis(System.currentTimeMillis());
}
GregorianCalendar(boolean ignored) {
super(TimeZone.getDefault());
setFirstDayOfWeek(SUNDAY);
setMinimalDaysInFirstWeek(1);
}
/**
* Adds the specified amount to a {@code Calendar} field.
*
* @param field the {@code Calendar} field to modify.
* @param value the amount to add to the field.
* @throws IllegalArgumentException if the specified field is DST_OFFSET or ZONE_OFFSET.
*/
@Override
public void add(int field, int value) {
if (value == 0) {
return;
}
if (field < 0 || field >= ZONE_OFFSET) {
throw new IllegalArgumentException();
}
if (field == ERA) {
complete();
if (fields[ERA] == AD) {
if (value >= 0) {
return;
}
set(ERA, BC);
} else {
if (value <= 0) {
return;
}
set(ERA, AD);
}
complete();
return;
}
if (field == YEAR || field == MONTH) {
complete();
if (field == MONTH) {
int month = fields[MONTH] + value;
if (month < 0) {
value = (month - 11) / 12;
month = 12 + (month % 12);
} else {
value = month / 12;
}
set(MONTH, month % 12);
}
set(YEAR, fields[YEAR] + value);
int days = daysInMonth(isLeapYear(fields[YEAR]), fields[MONTH]);
if (fields[DATE] > days) {
set(DATE, days);
}
complete();
return;
}
long multiplier = 0;
getTimeInMillis(); // Update the time
switch (field) {
case MILLISECOND:
time += value;
break;
case SECOND:
time += value * 1000L;
break;
case MINUTE:
time += value * 60000L;
break;
case HOUR:
case HOUR_OF_DAY:
time += value * 3600000L;
break;
case AM_PM:
multiplier = 43200000L;
break;
case DATE:
case DAY_OF_YEAR:
case DAY_OF_WEEK:
multiplier = 86400000L;
break;
case WEEK_OF_YEAR:
case WEEK_OF_MONTH:
case DAY_OF_WEEK_IN_MONTH:
multiplier = 604800000L;
break;
}
if (multiplier == 0) {
areFieldsSet = false;
complete();
return;
}
long delta = value * multiplier;
/*
* Attempt to keep the hour and minute constant when we've crossed a DST
* boundary and the user's units are AM_PM or larger. The typical
* consequence is that calls to add(DATE, 1) will add 23, 24 or 25 hours
* depending on whether the DST goes forward, constant, or backward.
*
* We know we've crossed a DST boundary if the new time will have a
* different timezone offset. Adjust by adding the difference of the two
* offsets. We don't adjust when doing so prevents the change from
* crossing the boundary.
*/
int zoneOffset = getTimeZone().getRawOffset();
int offsetBefore = getOffset(time + zoneOffset);
int offsetAfter = getOffset(time + zoneOffset + delta);
int dstDelta = offsetBefore - offsetAfter;
if (getOffset(time + zoneOffset + delta + dstDelta) == offsetAfter) {
delta += dstDelta;
}
time += delta;
areFieldsSet = false;
complete();
}
private void fullFieldsCalc(long timeVal, int zoneOffset) {
int millis = (int) (time % 86400000);
long days = timeVal / 86400000;
if (millis < 0) {
millis += 86400000;
days--;
}
// Cannot add ZONE_OFFSET to time as it might overflow
millis += zoneOffset;
while (millis < 0) {
millis += 86400000;
days--;
}
while (millis >= 86400000) {
millis -= 86400000;
days++;
}
int dayOfYear = computeYearAndDay(days, timeVal + zoneOffset);
fields[DAY_OF_YEAR] = dayOfYear;
if (fields[YEAR] == changeYear && gregorianCutover <= timeVal + zoneOffset) {
dayOfYear += currentYearSkew;
}
int month = dayOfYear / 32;
boolean leapYear = isLeapYear(fields[YEAR]);
int date = dayOfYear - daysInYear(leapYear, month);
if (date > daysInMonth(leapYear, month)) {
date -= daysInMonth(leapYear, month);
month++;
}
fields[DAY_OF_WEEK] = mod7(days - 3) + 1;
int dstOffset = fields[YEAR] <= 0 ? 0 : getTimeZone().getOffset(AD,
fields[YEAR], month, date, fields[DAY_OF_WEEK], millis);
if (fields[YEAR] > 0) {
dstOffset -= zoneOffset;
}
fields[DST_OFFSET] = dstOffset;
if (dstOffset != 0) {
long oldDays = days;
millis += dstOffset;
if (millis < 0) {
millis += 86400000;
days--;
} else if (millis >= 86400000) {
millis -= 86400000;
days++;
}
if (oldDays != days) {
dayOfYear = computeYearAndDay(days, timeVal - zoneOffset
+ dstOffset);
fields[DAY_OF_YEAR] = dayOfYear;
if (fields[YEAR] == changeYear && gregorianCutover <= timeVal - zoneOffset + dstOffset) {
dayOfYear += currentYearSkew;
}
month = dayOfYear / 32;
leapYear = isLeapYear(fields[YEAR]);
date = dayOfYear - daysInYear(leapYear, month);
if (date > daysInMonth(leapYear, month)) {
date -= daysInMonth(leapYear, month);
month++;
}
fields[DAY_OF_WEEK] = mod7(days - 3) + 1;
}
}
fields[MILLISECOND] = (millis % 1000);
millis /= 1000;
fields[SECOND] = (millis % 60);
millis /= 60;
fields[MINUTE] = (millis % 60);
millis /= 60;
fields[HOUR_OF_DAY] = (millis % 24);
fields[AM_PM] = fields[HOUR_OF_DAY] > 11 ? 1 : 0;
fields[HOUR] = fields[HOUR_OF_DAY] % 12;
if (fields[YEAR] <= 0) {
fields[ERA] = BC;
fields[YEAR] = -fields[YEAR] + 1;
} else {
fields[ERA] = AD;
}
fields[MONTH] = month;
fields[DATE] = date;
fields[DAY_OF_WEEK_IN_MONTH] = (date - 1) / 7 + 1;
fields[WEEK_OF_MONTH] = (date - 1 + mod7(days - date - 2
- (getFirstDayOfWeek() - 1))) / 7 + 1;
int daysFromStart = mod7(days - 3 - (fields[DAY_OF_YEAR] - 1)
- (getFirstDayOfWeek() - 1));
int week = (fields[DAY_OF_YEAR] - 1 + daysFromStart) / 7
+ (7 - daysFromStart >= getMinimalDaysInFirstWeek() ? 1 : 0);
if (week == 0) {
fields[WEEK_OF_YEAR] = 7 - mod7(daysFromStart
- (isLeapYear(fields[YEAR] - 1) ? 2 : 1)) >= getMinimalDaysInFirstWeek() ? 53
: 52;
} else if (fields[DAY_OF_YEAR] >= (leapYear ? 367 : 366)
- mod7(daysFromStart + (leapYear ? 2 : 1))) {
fields[WEEK_OF_YEAR] = 7 - mod7(daysFromStart + (leapYear ? 2 : 1)) >= getMinimalDaysInFirstWeek() ? 1
: week;
} else {
fields[WEEK_OF_YEAR] = week;
}
}
@Override
protected void computeFields() {
TimeZone timeZone = getTimeZone();
int dstOffset = timeZone.inDaylightTime(new Date(time)) ? timeZone.getDSTSavings() : 0;
int zoneOffset = timeZone.getRawOffset();
fields[DST_OFFSET] = dstOffset;
fields[ZONE_OFFSET] = zoneOffset;
fullFieldsCalc(time, zoneOffset);
for (int i = 0; i < FIELD_COUNT; i++) {
isSet[i] = true;
}
}
@Override
protected void computeTime() {
if (!isLenient()) {
if (isSet[HOUR_OF_DAY]) {
if (fields[HOUR_OF_DAY] < 0 || fields[HOUR_OF_DAY] > 23) {
throw new IllegalArgumentException();
}
} else if (isSet[HOUR] && (fields[HOUR] < 0 || fields[HOUR] > 11)) {
throw new IllegalArgumentException();
}
if (isSet[MINUTE] && (fields[MINUTE] < 0 || fields[MINUTE] > 59)) {
throw new IllegalArgumentException();
}
if (isSet[SECOND] && (fields[SECOND] < 0 || fields[SECOND] > 59)) {
throw new IllegalArgumentException();
}
if (isSet[MILLISECOND]
&& (fields[MILLISECOND] < 0 || fields[MILLISECOND] > 999)) {
throw new IllegalArgumentException();
}
if (isSet[WEEK_OF_YEAR]
&& (fields[WEEK_OF_YEAR] < 1 || fields[WEEK_OF_YEAR] > 53)) {
throw new IllegalArgumentException();
}
if (isSet[DAY_OF_WEEK]
&& (fields[DAY_OF_WEEK] < 1 || fields[DAY_OF_WEEK] > 7)) {
throw new IllegalArgumentException();
}
if (isSet[DAY_OF_WEEK_IN_MONTH]
&& (fields[DAY_OF_WEEK_IN_MONTH] < 1 || fields[DAY_OF_WEEK_IN_MONTH] > 6)) {
throw new IllegalArgumentException();
}
if (isSet[WEEK_OF_MONTH]
&& (fields[WEEK_OF_MONTH] < 1 || fields[WEEK_OF_MONTH] > 6)) {
throw new IllegalArgumentException();
}
if (isSet[AM_PM] && fields[AM_PM] != AM && fields[AM_PM] != PM) {
throw new IllegalArgumentException();
}
if (isSet[HOUR] && (fields[HOUR] < 0 || fields[HOUR] > 11)) {
throw new IllegalArgumentException();
}
if (isSet[YEAR]) {
if (isSet[ERA] && fields[ERA] == BC
&& (fields[YEAR] < 1 || fields[YEAR] > 292269054)) {
throw new IllegalArgumentException();
} else if (fields[YEAR] < 1 || fields[YEAR] > 292278994) {
throw new IllegalArgumentException();
}
}
if (isSet[MONTH] && (fields[MONTH] < 0 || fields[MONTH] > 11)) {
throw new IllegalArgumentException();
}
}
long timeVal;
long hour = 0;
if (isSet[HOUR_OF_DAY] && lastTimeFieldSet != HOUR) {
hour = fields[HOUR_OF_DAY];
} else if (isSet[HOUR]) {
hour = (fields[AM_PM] * 12) + fields[HOUR];
}
timeVal = hour * 3600000;
if (isSet[MINUTE]) {
timeVal += ((long) fields[MINUTE]) * 60000;
}
if (isSet[SECOND]) {
timeVal += ((long) fields[SECOND]) * 1000;
}
if (isSet[MILLISECOND]) {
timeVal += fields[MILLISECOND];
}
long days;
int year = isSet[YEAR] ? fields[YEAR] : 1970;
if (isSet[ERA]) {
// Always test for valid ERA, even if the Calendar is lenient
if (fields[ERA] != BC && fields[ERA] != AD) {
throw new IllegalArgumentException();
}
if (fields[ERA] == BC) {
year = 1 - year;
}
}
boolean weekMonthSet = isSet[WEEK_OF_MONTH]
|| isSet[DAY_OF_WEEK_IN_MONTH];
boolean useMonth = (isSet[DATE] || isSet[MONTH] || weekMonthSet)
&& lastDateFieldSet != DAY_OF_YEAR;
if (useMonth
&& (lastDateFieldSet == DAY_OF_WEEK || lastDateFieldSet == WEEK_OF_YEAR)) {
if (isSet[WEEK_OF_YEAR] && isSet[DAY_OF_WEEK]) {
useMonth = lastDateFieldSet != WEEK_OF_YEAR && weekMonthSet
&& isSet[DAY_OF_WEEK];
} else if (isSet[DAY_OF_YEAR]) {
useMonth = isSet[DATE] && isSet[MONTH];
}
}
if (useMonth) {
int month = fields[MONTH];
year += month / 12;
month %= 12;
if (month < 0) {
year--;
month += 12;
}
boolean leapYear = isLeapYear(year);
days = daysFromBaseYear(year) + daysInYear(leapYear, month);
boolean useDate = isSet[DATE];
if (useDate
&& (lastDateFieldSet == DAY_OF_WEEK
|| lastDateFieldSet == WEEK_OF_MONTH || lastDateFieldSet == DAY_OF_WEEK_IN_MONTH)) {
useDate = !(isSet[DAY_OF_WEEK] && weekMonthSet);
}
if (useDate) {
if (!isLenient()
&& (fields[DATE] < 1 || fields[DATE] > daysInMonth(
leapYear, month))) {
throw new IllegalArgumentException();
}
days += fields[DATE] - 1;
} else {
int dayOfWeek;
if (isSet[DAY_OF_WEEK]) {
dayOfWeek = fields[DAY_OF_WEEK] - 1;
} else {
dayOfWeek = getFirstDayOfWeek() - 1;
}
if (isSet[WEEK_OF_MONTH]
&& lastDateFieldSet != DAY_OF_WEEK_IN_MONTH) {
int skew = mod7(days - 3 - (getFirstDayOfWeek() - 1));
days += (fields[WEEK_OF_MONTH] - 1) * 7
+ mod7(skew + dayOfWeek - (days - 3)) - skew;
} else if (isSet[DAY_OF_WEEK_IN_MONTH]) {
if (fields[DAY_OF_WEEK_IN_MONTH] >= 0) {
days += mod7(dayOfWeek - (days - 3))
+ (fields[DAY_OF_WEEK_IN_MONTH] - 1) * 7;
} else {
days += daysInMonth(leapYear, month)
+ mod7(dayOfWeek
- (days + daysInMonth(leapYear, month) - 3))
+ fields[DAY_OF_WEEK_IN_MONTH] * 7;
}
} else if (isSet[DAY_OF_WEEK]) {
int skew = mod7(days - 3 - (getFirstDayOfWeek() - 1));
days += mod7(mod7(skew + dayOfWeek - (days - 3)) - skew);
}
}
} else {
boolean useWeekYear = isSet[WEEK_OF_YEAR]
&& lastDateFieldSet != DAY_OF_YEAR;
if (useWeekYear && isSet[DAY_OF_YEAR]) {
useWeekYear = isSet[DAY_OF_WEEK];
}
days = daysFromBaseYear(year);
if (useWeekYear) {
int dayOfWeek;
if (isSet[DAY_OF_WEEK]) {
dayOfWeek = fields[DAY_OF_WEEK] - 1;
} else {
dayOfWeek = getFirstDayOfWeek() - 1;
}
int skew = mod7(days - 3 - (getFirstDayOfWeek() - 1));
days += (fields[WEEK_OF_YEAR] - 1) * 7
+ mod7(skew + dayOfWeek - (days - 3)) - skew;
if (7 - skew < getMinimalDaysInFirstWeek()) {
days += 7;
}
} else if (isSet[DAY_OF_YEAR]) {
if (!isLenient()
&& (fields[DAY_OF_YEAR] < 1 || fields[DAY_OF_YEAR] > (365 + (isLeapYear(year) ? 1
: 0)))) {
throw new IllegalArgumentException();
}
days += fields[DAY_OF_YEAR] - 1;
} else if (isSet[DAY_OF_WEEK]) {
days += mod7(fields[DAY_OF_WEEK] - 1 - (days - 3));
}
}
lastDateFieldSet = 0;
timeVal += days * 86400000;
// Use local time to compare with the gregorian change
if (year == changeYear
&& timeVal >= gregorianCutover + julianError() * 86400000L) {
timeVal -= julianError() * 86400000L;
}
// It is not possible to simply subtract getOffset(timeVal) from timeVal
// to get UTC.
// The trick is needed for the moment when DST transition occurs,
// say 1:00 is a transition time when DST offset becomes +1 hour,
// then wall time in the interval 1:00 - 2:00 is invalid and is
// treated as UTC time.
long timeValWithoutDST = timeVal - getOffset(timeVal)
+ getTimeZone().getRawOffset();
timeVal -= getOffset(timeValWithoutDST);
// Need to update wall time in fields, since it was invalid due to DST
// transition
this.time = timeVal;
if (timeValWithoutDST != timeVal) {
computeFields();
areFieldsSet = true;
}
}
private int computeYearAndDay(long dayCount, long localTime) {
int year = 1970;
long days = dayCount;
if (localTime < gregorianCutover) {
days -= julianSkew;
}
int approxYears;
while ((approxYears = (int) (days / 365)) != 0) {
year = year + approxYears;
days = dayCount - daysFromBaseYear(year);
}
if (days < 0) {
year = year - 1;
days = days + daysInYear(year);
}
fields[YEAR] = year;
return (int) days + 1;
}
private long daysFromBaseYear(long year) {
if (year >= 1970) {
long days = (year - 1970) * 365 + ((year - 1969) / 4);
if (year > changeYear) {
days -= ((year - 1901) / 100) - ((year - 1601) / 400);
} else {
if (year == changeYear) {
days += currentYearSkew;
} else if (year == changeYear - 1) {
days += lastYearSkew;
} else {
days += julianSkew;
}
}
return days;
} else if (year <= changeYear) {
return (year - 1970) * 365 + ((year - 1972) / 4) + julianSkew;
}
return (year - 1970) * 365 + ((year - 1972) / 4) - ((year - 2000) / 100) + ((year - 2000) / 400);
}
private int daysInMonth() {
return daysInMonth(isLeapYear(fields[YEAR]), fields[MONTH]);
}
private int daysInMonth(boolean leapYear, int month) {
if (leapYear && month == FEBRUARY) {
return DaysInMonth[month] + 1;
}
return DaysInMonth[month];
}
private int daysInYear(int year) {
int daysInYear = isLeapYear(year) ? 366 : 365;
if (year == changeYear) {
daysInYear -= currentYearSkew;
}
if (year == changeYear - 1) {
daysInYear -= lastYearSkew;
}
return daysInYear;
}
private int daysInYear(boolean leapYear, int month) {
if (leapYear && month > FEBRUARY) {
return DaysInYear[month] + 1;
}
return DaysInYear[month];
}
/**
* Returns true if {@code object} is a GregorianCalendar with the same
* properties.
*/
@Override
public boolean equals(Object object) {
if (!(object instanceof GregorianCalendar)) {
return false;
}
if (object == this) {
return true;
}
return super.equals(object)
&& gregorianCutover == ((GregorianCalendar) object).gregorianCutover;
}
@Override
public int getActualMaximum(int field) {
int value;
if ((value = maximums[field]) == leastMaximums[field]) {
return value;
}
complete();
long orgTime = time;
int result = 0;
switch (field) {
case WEEK_OF_YEAR:
set(DATE, 31);
set(MONTH, DECEMBER);
result = get(WEEK_OF_YEAR);
if (result == 1) {
set(DATE, 31 - 7);
result = get(WEEK_OF_YEAR);
}
areFieldsSet = false;
break;
case WEEK_OF_MONTH:
set(DATE, daysInMonth());
result = get(WEEK_OF_MONTH);
areFieldsSet = false;
break;
case DATE:
return daysInMonth();
case DAY_OF_YEAR:
return daysInYear(fields[YEAR]);
case DAY_OF_WEEK_IN_MONTH:
result = get(DAY_OF_WEEK_IN_MONTH)
+ ((daysInMonth() - get(DATE)) / 7);
break;
case YEAR:
GregorianCalendar clone = (GregorianCalendar) clone();
if (get(ERA) == AD) {
clone.setTimeInMillis(Long.MAX_VALUE);
} else {
clone.setTimeInMillis(Long.MIN_VALUE);
}
result = clone.get(YEAR);
clone.set(YEAR, get(YEAR));
if (clone.before(this)) {
result--;
}
break;
case DST_OFFSET:
result = getMaximum(DST_OFFSET);
break;
}
time = orgTime;
return result;
}
/**
* Gets the minimum value of the specified field for the current date. For
* the gregorian calendar, this value is the same as
* {@code getMinimum()}.
*
* @param field the field.
* @return the minimum value of the specified field.
*/
@Override
public int getActualMinimum(int field) {
return getMinimum(field);
}
/**
* Gets the greatest minimum value of the specified field. For the gregorian
* calendar, this value is the same as {@code getMinimum()}.
*
* @param field the field.
* @return the greatest minimum value of the specified field.
*/
@Override
public int getGreatestMinimum(int field) {
return minimums[field];
}
/**
* Returns the gregorian change date of this calendar. This is the date on
* which the gregorian calendar came into effect.
*
* @return a {@code Date} which represents the gregorian change date.
*/
public final Date getGregorianChange() {
return new Date(gregorianCutover);
}
/**
* Gets the smallest maximum value of the specified field. For example, 28
* for the day of month field.
*
* @param field the field.
* @return the smallest maximum value of the specified field.
*/
@Override
public int getLeastMaximum(int field) {
// return value for WEEK_OF_YEAR should make corresponding changes when
// the gregorian change date have been reset.
if (gregorianCutover != defaultGregorianCutover
&& field == WEEK_OF_YEAR) {
long currentTimeInMillis = time;
setTimeInMillis(gregorianCutover);
int actual = getActualMaximum(field);
setTimeInMillis(currentTimeInMillis);
return actual;
}
return leastMaximums[field];
}
/**
* Gets the greatest maximum value of the specified field. For example, 31
* for the day of month field.
*
* @param field the field.
* @return the greatest maximum value of the specified field.
*/
@Override
public int getMaximum(int field) {
return maximums[field];
}
/**
* Gets the smallest minimum value of the specified field.
*
* @param field the field.
* @return the smallest minimum value of the specified field.
*/
@Override
public int getMinimum(int field) {
return minimums[field];
}
private int getOffset(long localTime) {
TimeZone timeZone = getTimeZone();
long dayCount = localTime / 86400000;
int millis = (int) (localTime % 86400000);
if (millis < 0) {
millis += 86400000;
dayCount--;
}
int year = 1970;
long days = dayCount;
if (localTime < gregorianCutover) {
days -= julianSkew;
}
int approxYears;
while ((approxYears = (int) (days / 365)) != 0) {
year = year + approxYears;
days = dayCount - daysFromBaseYear(year);
}
if (days < 0) {
year = year - 1;
days = days + 365 + (isLeapYear(year) ? 1 : 0);
if (year == changeYear && localTime < gregorianCutover) {
days -= julianError();
}
}
if (year <= 0) {
return timeZone.getRawOffset();
}
int dayOfYear = (int) days + 1;
int month = dayOfYear / 32;
boolean leapYear = isLeapYear(year);
int date = dayOfYear - daysInYear(leapYear, month);
if (date > daysInMonth(leapYear, month)) {
date -= daysInMonth(leapYear, month);
month++;
}
int dayOfWeek = mod7(dayCount - 3) + 1;
return timeZone.getOffset(AD, year, month, date, dayOfWeek, millis);
}
@Override
public int hashCode() {
return super.hashCode()
+ ((int) (gregorianCutover >>> 32) ^ (int) gregorianCutover);
}
/**
* Returns true if {@code year} is a leap year.
*/
public boolean isLeapYear(int year) {
if (year > changeYear) {
return year % 4 == 0 && (year % 100 != 0 || year % 400 == 0);
}
return year % 4 == 0;
}
private int julianError() {
return changeYear / 100 - changeYear / 400 - 2;
}
private int mod(int value, int mod) {
int rem = value % mod;
if (value < 0 && rem < 0) {
return rem + mod;
}
return rem;
}
private int mod7(long num1) {
int rem = (int) (num1 % 7);
if (num1 < 0 && rem < 0) {
return rem + 7;
}
return rem;
}
/**
* Adds the specified amount the specified field and wraps the value of the
* field when it goes beyond the maximum or minimum value for the current
* date. Other fields will be adjusted as required to maintain a consistent
* date.
*
* @param field the field to roll.
* @param value the amount to add.
* @throws IllegalArgumentException if an invalid field is specified.
*/
@Override
public void roll(int field, int value) {
if (value == 0) {
return;
}
if (field < 0 || field >= ZONE_OFFSET) {
throw new IllegalArgumentException();
}
complete();
int days, day, mod, maxWeeks, newWeek;
int max = -1;
switch (field) {
case YEAR:
max = maximums[field];
break;
case WEEK_OF_YEAR:
days = daysInYear(fields[YEAR]);
day = DAY_OF_YEAR;
mod = mod7(fields[DAY_OF_WEEK] - fields[day]
- (getFirstDayOfWeek() - 1));
maxWeeks = (days - 1 + mod) / 7 + 1;
newWeek = mod(fields[field] - 1 + value, maxWeeks) + 1;
if (newWeek == maxWeeks) {
int addDays = (newWeek - fields[field]) * 7;
if (fields[day] > addDays && fields[day] + addDays > days) {
set(field, 1);
} else {
set(field, newWeek - 1);
}
} else if (newWeek == 1) {
int week = (fields[day] - ((fields[day] - 1) / 7 * 7) - 1 + mod) / 7 + 1;
if (week > 1) {
set(field, 1);
} else {
set(field, newWeek);
}
} else {
set(field, newWeek);
}
break;
case WEEK_OF_MONTH:
days = daysInMonth();
day = DATE;
mod = mod7(fields[DAY_OF_WEEK] - fields[day]
- (getFirstDayOfWeek() - 1));
maxWeeks = (days - 1 + mod) / 7 + 1;
newWeek = mod(fields[field] - 1 + value, maxWeeks) + 1;
if (newWeek == maxWeeks) {
if (fields[day] + (newWeek - fields[field]) * 7 > days) {
set(day, days);
} else {
set(field, newWeek);
}
} else if (newWeek == 1) {
int week = (fields[day] - ((fields[day] - 1) / 7 * 7) - 1 + mod) / 7 + 1;
if (week > 1) {
set(day, 1);
} else {
set(field, newWeek);
}
} else {
set(field, newWeek);
}
break;
case DATE:
max = daysInMonth();
break;
case DAY_OF_YEAR:
max = daysInYear(fields[YEAR]);
break;
case DAY_OF_WEEK:
max = maximums[field];
lastDateFieldSet = WEEK_OF_MONTH;
break;
case DAY_OF_WEEK_IN_MONTH:
max = (fields[DATE] + ((daysInMonth() - fields[DATE]) / 7 * 7) - 1) / 7 + 1;
break;
case ERA:
case MONTH:
case AM_PM:
case HOUR:
case HOUR_OF_DAY:
case MINUTE:
case SECOND:
case MILLISECOND:
set(field, mod(fields[field] + value, maximums[field] + 1));
if (field == MONTH && fields[DATE] > daysInMonth()) {
set(DATE, daysInMonth());
} else if (field == AM_PM) {
lastTimeFieldSet = HOUR;
}
break;
}
if (max != -1) {
set(field, mod(fields[field] - 1 + value, max) + 1);
}
complete();
}
/**
* Increments or decrements the specified field and wraps the value of the
* field when it goes beyond the maximum or minimum value for the current
* date. Other fields will be adjusted as required to maintain a consistent
* date. For example, March 31 will roll to April 30 when rolling the month
* field.
*
* @param field the field to roll.
* @param increment {@code true} to increment the field, {@code false} to
* decrement.
* @throws IllegalArgumentException if an invalid field is specified.
*/
@Override
public void roll(int field, boolean increment) {
roll(field, increment ? 1 : -1);
}
/**
* Sets the gregorian change date of this calendar.
*/
public void setGregorianChange(Date date) {
gregorianCutover = date.getTime();
GregorianCalendar cal = new GregorianCalendar(TimeZone.getTimeZone("GMT"));
cal.setTime(date);
changeYear = cal.get(YEAR);
if (cal.get(ERA) == BC) {
changeYear = 1 - changeYear;
}
julianSkew = ((changeYear - 2000) / 400) + julianError()
- ((changeYear - 2000) / 100);
int dayOfYear = cal.get(DAY_OF_YEAR);
if (dayOfYear < julianSkew) {
currentYearSkew = dayOfYear - 1;
lastYearSkew = julianSkew - dayOfYear + 1;
} else {
lastYearSkew = 0;
currentYearSkew = julianSkew;
}
}
private void writeObject(ObjectOutputStream stream) throws IOException {
stream.defaultWriteObject();
}
private void readObject(ObjectInputStream stream) throws IOException, ClassNotFoundException {
stream.defaultReadObject();
setGregorianChange(new Date(gregorianCutover));
}
}