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// © 2016 and later: Unicode, Inc. and others.
// License & terms of use: http://www.unicode.org/copyright.html#License
/*
*******************************************************************************
* Copyright (C) 1996-2016, International Business Machines Corporation and
* others. All Rights Reserved.
*******************************************************************************
*/
package com.ibm.icu.util;
import java.util.Date;
import java.util.Locale;
import com.ibm.icu.impl.CalendarCache;
import com.ibm.icu.util.ULocale.Category;
/**
* HebrewCalendar is a subclass of Calendar
* that that implements the traditional Hebrew calendar.
* This is the civil calendar in Israel and the liturgical calendar
* of the Jewish faith worldwide.
*
* The Hebrew calendar is lunisolar and thus has a number of interesting
* properties that distinguish it from the Gregorian. Months start
* on the day of (an arithmetic approximation of) each new moon. Since the
* solar year (approximately 365.24 days) is not an even multiple of
* the lunar month (approximately 29.53 days) an extra "leap month" is
* inserted in 7 out of every 19 years. To make matters even more
* interesting, the start of a year can be delayed by up to three days
* in order to prevent certain holidays from falling on the Sabbath and
* to prevent certain illegal year lengths. Finally, the lengths of certain
* months can vary depending on the number of days in the year.
*
* The leap month is known as "Adar 1" and is inserted between the
* months of Shevat and Adar in leap years. Since the leap month does
* not come at the end of the year, calculations involving
* month numbers are particularly complex. Users of this class should
* make sure to use the {@link #roll roll} and {@link #add add} methods
* rather than attempting to perform date arithmetic by manipulating
* the fields directly.
*
* Note: In the traditional Hebrew calendar, days start at sunset.
* However, in order to keep the time fields in this class
* synchronized with those of the other calendars and with local clock time,
* we treat days and months as beginning at midnight,
* roughly 6 hours after the corresponding sunset.
*
* If you are interested in more information on the rules behind the Hebrew
* calendar, see one of the following references:
*
* - "Calendrical Calculations",
* by Nachum Dershowitz & Edward Reingold, Cambridge University Press, 1997, pages 85-91.
*
*
- Hebrew Calendar Science and Myths,
*
* http://web.archive.org/web/20090423084613/http://www.geocities.com/Athens/1584/
*
*
- The Calendar FAQ,
*
* http://www.faqs.org/faqs/calendars/faq/
*
*
*
* This class should not be subclassed.
*
* HebrewCalendar usually should be instantiated using
* {@link com.ibm.icu.util.Calendar#getInstance(ULocale)} passing in a ULocale
* with the tag "@calendar=hebrew".
*
* @see com.ibm.icu.util.GregorianCalendar
* @see com.ibm.icu.util.Calendar
*
* @author Laura Werner
* @author Alan Liu
* @stable ICU 2.8
*/
public class HebrewCalendar extends Calendar {
// jdk1.4.2 serialver
private static final long serialVersionUID = -1952524560588825816L;
//-------------------------------------------------------------------------
// Tons o' Constants...
//-------------------------------------------------------------------------
/**
* Constant for Tishri, the 1st month of the Hebrew year.
* @stable ICU 2.8
*/
public static final int TISHRI = 0;
/**
* Constant for Heshvan, the 2nd month of the Hebrew year.
* @stable ICU 2.8
*/
public static final int HESHVAN = 1;
/**
* Constant for Kislev, the 3rd month of the Hebrew year.
* @stable ICU 2.8
*/
public static final int KISLEV = 2;
/**
* Constant for Tevet, the 4th month of the Hebrew year.
* @stable ICU 2.8
*/
public static final int TEVET = 3;
/**
* Constant for Shevat, the 5th month of the Hebrew year.
* @stable ICU 2.8
*/
public static final int SHEVAT = 4;
/**
* Constant for Adar I, the 6th month of the Hebrew year
* (present in leap years only). In non-leap years, the calendar
* jumps from Shevat (5th month) to Adar (7th month).
* @stable ICU 2.8
*/
public static final int ADAR_1 = 5;
/**
* Constant for the Adar, the 7th month of the Hebrew year.
* @stable ICU 2.8
*/
public static final int ADAR = 6;
/**
* Constant for Nisan, the 8th month of the Hebrew year.
* @stable ICU 2.8
*/
public static final int NISAN = 7;
/**
* Constant for Iyar, the 9th month of the Hebrew year.
* @stable ICU 2.8
*/
public static final int IYAR = 8;
/**
* Constant for Sivan, the 10th month of the Hebrew year.
* @stable ICU 2.8
*/
public static final int SIVAN = 9;
/**
* Constant for Tammuz, the 11th month of the Hebrew year.
* @stable ICU 2.8
*/
public static final int TAMUZ = 10;
/**
* Constant for Av, the 12th month of the Hebrew year.
* @stable ICU 2.8
*/
public static final int AV = 11;
/**
* Constant for Elul, the 13th month of the Hebrew year.
* @stable ICU 2.8
*/
public static final int ELUL = 12;
/**
* The absolute date, in milliseconds since 1/1/1970 AD, Gregorian,
* of the start of the Hebrew calendar. In order to keep this calendar's
* time of day in sync with that of the Gregorian calendar, we use
* midnight, rather than sunset the day before.
*/
//private static final long EPOCH_MILLIS = -180799862400000L; // 1/1/1 HY
private static final int LIMITS[][] = {
// Minimum Greatest Least Maximum
// Minimum Maximum
{ 0, 0, 0, 0 }, // ERA
{ -5000000, -5000000, 5000000, 5000000 }, // YEAR
{ 0, 0, 12, 12 }, // MONTH
{ 1, 1, 51, 56 }, // WEEK_OF_YEAR
{/* */}, // WEEK_OF_MONTH
{ 1, 1, 29, 30 }, // DAY_OF_MONTH
{ 1, 1, 353, 385 }, // DAY_OF_YEAR
{/* */}, // DAY_OF_WEEK
{ -1, -1, 5, 5 }, // DAY_OF_WEEK_IN_MONTH
{/* */}, // AM_PM
{/* */}, // HOUR
{/* */}, // HOUR_OF_DAY
{/* */}, // MINUTE
{/* */}, // SECOND
{/* */}, // MILLISECOND
{/* */}, // ZONE_OFFSET
{/* */}, // DST_OFFSET
{ -5000000, -5000000, 5000000, 5000000 }, // YEAR_WOY
{/* */}, // DOW_LOCAL
{ -5000000, -5000000, 5000000, 5000000 }, // EXTENDED_YEAR
{/* */}, // JULIAN_DAY
{/* */}, // MILLISECONDS_IN_DAY
};
/**
* The lengths of the Hebrew months. This is complicated, because there
* are three different types of years, or six if you count leap years.
* Due to the rules for postponing the start of the year to avoid having
* certain holidays fall on the sabbath, the year can end up being three
* different lengths, called "deficient", "normal", and "complete".
*/
private static final int MONTH_LENGTH[][] = {
// Deficient Normal Complete
{ 30, 30, 30 }, //Tishri
{ 29, 29, 30 }, //Heshvan
{ 29, 30, 30 }, //Kislev
{ 29, 29, 29 }, //Tevet
{ 30, 30, 30 }, //Shevat
{ 30, 30, 30 }, //Adar I (leap years only)
{ 29, 29, 29 }, //Adar
{ 30, 30, 30 }, //Nisan
{ 29, 29, 29 }, //Iyar
{ 30, 30, 30 }, //Sivan
{ 29, 29, 29 }, //Tammuz
{ 30, 30, 30 }, //Av
{ 29, 29, 29 }, //Elul
};
/**
* The cumulative # of days to the end of each month in a non-leap year
* Although this can be calculated from the MONTH_LENGTH table,
* keeping it around separately makes some calculations a lot faster
*/
private static final int MONTH_START[][] = {
// Deficient Normal Complete
{ 0, 0, 0 }, // (placeholder)
{ 30, 30, 30 }, // Tishri
{ 59, 59, 60 }, // Heshvan
{ 88, 89, 90 }, // Kislev
{ 117, 118, 119 }, // Tevet
{ 147, 148, 149 }, // Shevat
{ 147, 148, 149 }, // (Adar I placeholder)
{ 176, 177, 178 }, // Adar
{ 206, 207, 208 }, // Nisan
{ 235, 236, 237 }, // Iyar
{ 265, 266, 267 }, // Sivan
{ 294, 295, 296 }, // Tammuz
{ 324, 325, 326 }, // Av
{ 353, 354, 355 }, // Elul
};
/**
* The cumulative # of days to the end of each month in a leap year
*/
private static final int LEAP_MONTH_START[][] = {
// Deficient Normal Complete
{ 0, 0, 0 }, // (placeholder)
{ 30, 30, 30 }, // Tishri
{ 59, 59, 60 }, // Heshvan
{ 88, 89, 90 }, // Kislev
{ 117, 118, 119 }, // Tevet
{ 147, 148, 149 }, // Shevat
{ 177, 178, 179 }, // Adar I
{ 206, 207, 208 }, // Adar II
{ 236, 237, 238 }, // Nisan
{ 265, 266, 267 }, // Iyar
{ 295, 296, 297 }, // Sivan
{ 324, 325, 326 }, // Tammuz
{ 354, 355, 356 }, // Av
{ 383, 384, 385 }, // Elul
};
//-------------------------------------------------------------------------
// Data Members...
//-------------------------------------------------------------------------
private static CalendarCache cache = new CalendarCache();
//-------------------------------------------------------------------------
// Constructors...
//-------------------------------------------------------------------------
/**
* Constructs a default HebrewCalendar using the current time
* in the default time zone with the default FORMAT locale.
* @see Category#FORMAT
* @stable ICU 2.8
*/
public HebrewCalendar() {
this(TimeZone.getDefault(), ULocale.getDefault(Category.FORMAT));
}
/**
* Constructs a HebrewCalendar based on the current time
* in the given time zone with the default FORMAT locale.
*
* @param zone The time zone for the new calendar.
* @see Category#FORMAT
* @stable ICU 2.8
*/
public HebrewCalendar(TimeZone zone) {
this(zone, ULocale.getDefault(Category.FORMAT));
}
/**
* Constructs a HebrewCalendar based on the current time
* in the default time zone with the given locale.
*
* @param aLocale The locale for the new calendar.
* @stable ICU 2.8
*/
public HebrewCalendar(Locale aLocale) {
this(TimeZone.getDefault(), aLocale);
}
/**
* Constructs a HebrewCalendar based on the current time
* in the default time zone with the given locale.
*
* @param locale The locale for the new calendar.
* @stable ICU 3.2
*/
public HebrewCalendar(ULocale locale) {
this(TimeZone.getDefault(), locale);
}
/**
* Constructs a HebrewCalendar based on the current time
* in the given time zone with the given locale.
*
* @param zone The time zone for the new calendar.
*
* @param aLocale The locale for the new calendar.
* @stable ICU 2.8
*/
public HebrewCalendar(TimeZone zone, Locale aLocale) {
super(zone, aLocale);
setTimeInMillis(System.currentTimeMillis());
}
/**
* Constructs a HebrewCalendar based on the current time
* in the given time zone with the given locale.
*
* @param zone The time zone for the new calendar.
*
* @param locale The locale for the new calendar.
* @stable ICU 3.2
*/
public HebrewCalendar(TimeZone zone, ULocale locale) {
super(zone, locale);
setTimeInMillis(System.currentTimeMillis());
}
/**
* Constructs a HebrewCalendar with the given date set
* in the default time zone with the default FORMAT locale.
*
* @param year The value used to set the calendar's {@link #YEAR YEAR} time field.
*
* @param month The value used to set the calendar's {@link #MONTH MONTH} time field.
* The value is 0-based. e.g., 0 for Tishri.
*
* @param date The value used to set the calendar's {@link #DATE DATE} time field.
* @see Category#FORMAT
* @stable ICU 2.8
*/
public HebrewCalendar(int year, int month, int date) {
super(TimeZone.getDefault(), ULocale.getDefault(Category.FORMAT));
this.set(YEAR, year);
this.set(MONTH, month);
this.set(DATE, date);
}
/**
* Constructs a HebrewCalendar with the given date set
* in the default time zone with the default FORMAT locale.
*
* @param date The date to which the new calendar is set.
* @see Category#FORMAT
* @stable ICU 2.8
*/
public HebrewCalendar(Date date) {
super(TimeZone.getDefault(), ULocale.getDefault(Category.FORMAT));
this.setTime(date);
}
/**
* Constructs a HebrewCalendar with the given date
* and time set for the default time zone with the default FORMAT locale.
*
* @param year The value used to set the calendar's {@link #YEAR YEAR} time field.
*
* @param month The value used to set the calendar's {@link #MONTH MONTH} time field.
* The value is 0-based. e.g., 0 for Tishri.
*
* @param date The value used to set the calendar's {@link #DATE DATE} time field.
*
* @param hour The value used to set the calendar's {@link #HOUR_OF_DAY HOUR_OF_DAY} time field.
*
* @param minute The value used to set the calendar's {@link #MINUTE MINUTE} time field.
*
* @param second The value used to set the calendar's {@link #SECOND SECOND} time field.
* @see Category#FORMAT
* @stable ICU 2.8
*/
public HebrewCalendar(int year, int month, int date, int hour,
int minute, int second)
{
super(TimeZone.getDefault(), ULocale.getDefault(Category.FORMAT));
this.set(YEAR, year);
this.set(MONTH, month);
this.set(DATE, date);
this.set(HOUR_OF_DAY, hour);
this.set(MINUTE, minute);
this.set(SECOND, second);
}
//-------------------------------------------------------------------------
// Rolling and adding functions overridden from Calendar
//
// These methods call through to the default implementation in IBMCalendar
// for most of the fields and only handle the unusual ones themselves.
//-------------------------------------------------------------------------
/**
* Add a signed amount to a specified field, using this calendar's rules.
* For example, to add three days to the current date, you can call
* add(Calendar.DATE, 3).
*
* When adding to certain fields, the values of other fields may conflict and
* need to be changed. For example, when adding one to the {@link #MONTH MONTH} field
* for the date "30 Av 5758", the {@link #DAY_OF_MONTH DAY_OF_MONTH} field
* must be adjusted so that the result is "29 Elul 5758" rather than the invalid
* "30 Elul 5758".
*
* This method is able to add to
* all fields except for {@link #ERA ERA}, {@link #DST_OFFSET DST_OFFSET},
* and {@link #ZONE_OFFSET ZONE_OFFSET}.
*
* Note: You should always use {@link #roll roll} and add rather
* than attempting to perform arithmetic operations directly on the fields
* of a HebrewCalendar. Since the {@link #MONTH MONTH} field behaves
* discontinuously in non-leap years, simple arithmetic can give invalid results.
*
* @param field the time field.
* @param amount the amount to add to the field.
*
* @exception IllegalArgumentException if the field is invalid or refers
* to a field that cannot be handled by this method.
* @stable ICU 2.8
*/
public void add(int field, int amount)
{
switch (field) {
case MONTH:
{
// We can't just do a set(MONTH, get(MONTH) + amount). The
// reason is ADAR_1. Suppose amount is +2 and we land in
// ADAR_1 -- then we have to bump to ADAR_2 aka ADAR. But
// if amount is -2 and we land in ADAR_1, then we have to
// bump the other way -- down to SHEVAT. - Alan 11/00
int month = get(MONTH);
int year = get(YEAR);
boolean acrossAdar1;
if (amount > 0) {
acrossAdar1 = (month < ADAR_1); // started before ADAR_1?
month += amount;
for (;;) {
if (acrossAdar1 && month>=ADAR_1 && !isLeapYear(year)) {
++month;
}
if (month <= ELUL) {
break;
}
month -= ELUL+1;
++year;
acrossAdar1 = true;
}
} else {
acrossAdar1 = (month > ADAR_1); // started after ADAR_1?
month += amount;
for (;;) {
if (acrossAdar1 && month<=ADAR_1 && !isLeapYear(year)) {
--month;
}
if (month >= 0) {
break;
}
month += ELUL+1;
--year;
acrossAdar1 = true;
}
}
set(MONTH, month);
set(YEAR, year);
pinField(DAY_OF_MONTH);
break;
}
default:
super.add(field, amount);
break;
}
}
/**
* Rolls (up/down) a specified amount time on the given field. For
* example, to roll the current date up by three days, you can call
* roll(Calendar.DATE, 3). If the
* field is rolled past its maximum allowable value, it will "wrap" back
* to its minimum and continue rolling.
* For example, calling roll(Calendar.DATE, 10)
* on a Hebrew calendar set to "25 Av 5758" will result in the date "5 Av 5758".
*
* When rolling certain fields, the values of other fields may conflict and
* need to be changed. For example, when rolling the {@link #MONTH MONTH} field
* upward by one for the date "30 Av 5758", the {@link #DAY_OF_MONTH DAY_OF_MONTH} field
* must be adjusted so that the result is "29 Elul 5758" rather than the invalid
* "30 Elul".
*
* This method is able to roll
* all fields except for {@link #ERA ERA}, {@link #DST_OFFSET DST_OFFSET},
* and {@link #ZONE_OFFSET ZONE_OFFSET}. Subclasses may, of course, add support for
* additional fields in their overrides of roll.
*
* Note: You should always use roll and {@link #add add} rather
* than attempting to perform arithmetic operations directly on the fields
* of a HebrewCalendar. Since the {@link #MONTH MONTH} field behaves
* discontinuously in non-leap years, simple arithmetic can give invalid results.
*
* @param field the time field.
* @param amount the amount by which the field should be rolled.
*
* @exception IllegalArgumentException if the field is invalid or refers
* to a field that cannot be handled by this method.
* @stable ICU 2.8
*/
public void roll(int field, int amount)
{
switch (field) {
case MONTH:
{
int month = get(MONTH);
int year = get(YEAR);
boolean leapYear = isLeapYear(year);
int yearLength = monthsInYear(year);
int newMonth = month + (amount % yearLength);
//
// If it's not a leap year and we're rolling past the missing month
// of ADAR_1, we need to roll an extra month to make up for it.
//
if (!leapYear) {
if (amount > 0 && month < ADAR_1 && newMonth >= ADAR_1) {
newMonth++;
} else if (amount < 0 && month > ADAR_1 && newMonth <= ADAR_1) {
newMonth--;
}
}
set(MONTH, (newMonth + 13) % 13);
pinField(DAY_OF_MONTH);
return;
}
default:
super.roll(field, amount);
}
}
//-------------------------------------------------------------------------
// Support methods
//-------------------------------------------------------------------------
// Hebrew date calculations are performed in terms of days, hours, and
// "parts" (or halakim), which are 1/1080 of an hour, or 3 1/3 seconds.
private static final long HOUR_PARTS = 1080;
private static final long DAY_PARTS = 24*HOUR_PARTS;
// An approximate value for the length of a lunar month.
// It is used to calculate the approximate year and month of a given
// absolute date.
static private final int MONTH_DAYS = 29;
static private final long MONTH_FRACT = 12*HOUR_PARTS + 793;
static private final long MONTH_PARTS = MONTH_DAYS*DAY_PARTS + MONTH_FRACT;
// The time of the new moon (in parts) on 1 Tishri, year 1 (the epoch)
// counting from noon on the day before. BAHARAD is an abbreviation of
// Bet (Monday), Hey (5 hours from sunset), Resh-Daled (204).
static private final long BAHARAD = 11*HOUR_PARTS + 204;
/**
* Finds the day # of the first day in the given Hebrew year.
* To do this, we want to calculate the time of the Tishri 1 new moon
* in that year.
*
* The algorithm here is similar to ones described in a number of
* references, including:
*
* - "Calendrical Calculations", by Nachum Dershowitz & Edward Reingold,
* Cambridge University Press, 1997, pages 85-91.
*
*
- Hebrew Calendar Science and Myths,
*
* http://www.geocities.com/Athens/1584/
*
*
- The Calendar FAQ,
*
* http://www.faqs.org/faqs/calendars/faq/
*
*/
private static long startOfYear(int year)
{
long day = cache.get(year);
if (day == CalendarCache.EMPTY) {
int months = (235 * year - 234) / 19; // # of months before year
long frac = months * MONTH_FRACT + BAHARAD; // Fractional part of day #
day = months * 29 + (frac / DAY_PARTS); // Whole # part of calculation
frac = frac % DAY_PARTS; // Time of day
int wd = (int)(day % 7); // Day of week (0 == Monday)
if (wd == 2 || wd == 4 || wd == 6) {
// If the 1st is on Sun, Wed, or Fri, postpone to the next day
day += 1;
wd = (int)(day % 7);
}
if (wd == 1 && frac > 15*HOUR_PARTS+204 && !isLeapYear(year) ) {
// If the new moon falls after 3:11:20am (15h204p from the previous noon)
// on a Tuesday and it is not a leap year, postpone by 2 days.
// This prevents 356-day years.
day += 2;
}
else if (wd == 0 && frac > 21*HOUR_PARTS+589 && isLeapYear(year-1) ) {
// If the new moon falls after 9:32:43 1/3am (21h589p from yesterday noon)
// on a Monday and *last* year was a leap year, postpone by 1 day.
// Prevents 382-day years.
day += 1;
}
cache.put(year, day);
}
return day;
}
/*
* Find the day of the week for a given day
*
* @param day The # of days since the start of the Hebrew calendar,
* 1-based (i.e. 1/1/1 AM is day 1).
*/
/*private static int absoluteDayToDayOfWeek(long day)
{
// We know that 1/1/1 AM is a Monday, which makes the math easy...
return (int)(day % 7) + 1;
}*/
/**
* Returns the the type of a given year.
* 0 "Deficient" year with 353 or 383 days
* 1 "Normal" year with 354 or 384 days
* 2 "Complete" year with 355 or 385 days
*/
private final int yearType(int year)
{
int yearLength = handleGetYearLength(year);
if (yearLength > 380) {
yearLength -= 30; // Subtract length of leap month.
}
int type = 0;
switch (yearLength) {
case 353:
type = 0; break;
case 354:
type = 1; break;
case 355:
type = 2; break;
default:
throw new IllegalArgumentException("Illegal year length " + yearLength + " in year " + year);
}
return type;
}
/**
* Determine whether a given Hebrew year is a leap year
*
* The rule here is that if (year % 19) == 0, 3, 6, 8, 11, 14, or 17.
* The formula below performs the same test, believe it or not.
* @internal
* @deprecated This API is ICU internal only.
*/
@Deprecated
public static boolean isLeapYear(int year) {
//return (year * 12 + 17) % 19 >= 12;
int x = (year*12 + 17) % 19;
return x >= ((x < 0) ? -7 : 12);
}
private static int monthsInYear(int year) {
return isLeapYear(year) ? 13 : 12;
}
//-------------------------------------------------------------------------
// Calendar framework
//-------------------------------------------------------------------------
/**
* @stable ICU 2.8
*/
protected int handleGetLimit(int field, int limitType) {
return LIMITS[field][limitType];
}
/**
* Returns the length of the given month in the given year
* @stable ICU 2.8
*/
protected int handleGetMonthLength(int extendedYear, int month) {
// Resolve out-of-range months. This is necessary in order to
// obtain the correct year. We correct to
// a 12- or 13-month year (add/subtract 12 or 13, depending
// on the year) but since we _always_ number from 0..12, and
// the leap year determines whether or not month 5 (Adar 1)
// is present, we allow 0..12 in any given year.
while (month < 0) {
month += monthsInYear(--extendedYear);
}
// Careful: allow 0..12 in all years
while (month > 12) {
month -= monthsInYear(extendedYear++);
}
switch (month) {
case HESHVAN:
case KISLEV:
// These two month lengths can vary
return MONTH_LENGTH[month][yearType(extendedYear)];
default:
// The rest are a fixed length
return MONTH_LENGTH[month][0];
}
}
/**
* Returns the number of days in the given Hebrew year
* @stable ICU 2.8
*/
protected int handleGetYearLength(int eyear) {
return (int)(startOfYear(eyear+1) - startOfYear(eyear));
}
/**
* {@inheritDoc}
*
* Overrides {@link Calendar#validateField(int)} to provide
* special handling for month validation for Hebrew calendar.
* @internal
* @deprecated This API is ICU internal only.
*/
@Deprecated
protected void validateField(int field) {
if (field == MONTH && !isLeapYear(handleGetExtendedYear()) && internalGet(MONTH) == ADAR_1) {
throw new IllegalArgumentException("MONTH cannot be ADAR_1(5) except leap years");
}
super.validateField(field);
}
//-------------------------------------------------------------------------
// Functions for converting from milliseconds to field values
//-------------------------------------------------------------------------
/**
* Subclasses may override this method to compute several fields
* specific to each calendar system. These are:
*
*
- ERA
*
- YEAR
*
- MONTH
*
- DAY_OF_MONTH
*
- DAY_OF_YEAR
*
- EXTENDED_YEAR
*
* Subclasses can refer to the DAY_OF_WEEK and DOW_LOCAL fields,
* which will be set when this method is called. Subclasses can
* also call the getGregorianXxx() methods to obtain Gregorian
* calendar equivalents for the given Julian day.
*
* In addition, subclasses should compute any subclass-specific
* fields, that is, fields from BASE_FIELD_COUNT to
* getFieldCount() - 1.
* @stable ICU 2.8
*/
protected void handleComputeFields(int julianDay) {
long d = julianDay - 347997;
long m = (d * DAY_PARTS) / MONTH_PARTS; // Months (approx)
int year = (int)((19 * m + 234) / 235) + 1; // Years (approx)
long ys = startOfYear(year); // 1st day of year
int dayOfYear = (int)(d - ys);
// Because of the postponement rules, it's possible to guess wrong. Fix it.
while (dayOfYear < 1) {
year--;
ys = startOfYear(year);
dayOfYear = (int)(d - ys);
}
// Now figure out which month we're in, and the date within that month
int yearType = yearType(year);
int monthStart[][] = isLeapYear(year) ? LEAP_MONTH_START : MONTH_START;
int month = 0;
while (dayOfYear > monthStart[month][yearType]) {
month++;
}
month--;
int dayOfMonth = dayOfYear - monthStart[month][yearType];
internalSet(ERA, 0);
internalSet(YEAR, year);
internalSet(EXTENDED_YEAR, year);
internalSet(MONTH, month);
internalSet(DAY_OF_MONTH, dayOfMonth);
internalSet(DAY_OF_YEAR, dayOfYear);
}
//-------------------------------------------------------------------------
// Functions for converting from field values to milliseconds
//-------------------------------------------------------------------------
/**
* @stable ICU 2.8
*/
protected int handleGetExtendedYear() {
int year;
if (newerField(EXTENDED_YEAR, YEAR) == EXTENDED_YEAR) {
year = internalGet(EXTENDED_YEAR, 1); // Default to year 1
} else {
year = internalGet(YEAR, 1); // Default to year 1
}
return year;
}
/**
* Return JD of start of given month/year.
* @stable ICU 2.8
*/
protected int handleComputeMonthStart(int eyear, int month, boolean useMonth) {
// Resolve out-of-range months. This is necessary in order to
// obtain the correct year. We correct to
// a 12- or 13-month year (add/subtract 12 or 13, depending
// on the year) but since we _always_ number from 0..12, and
// the leap year determines whether or not month 5 (Adar 1)
// is present, we allow 0..12 in any given year.
while (month < 0) {
month += monthsInYear(--eyear);
}
// Careful: allow 0..12 in all years
while (month > 12) {
month -= monthsInYear(eyear++);
}
long day = startOfYear(eyear);
if (month != 0) {
if (isLeapYear(eyear)) {
day += LEAP_MONTH_START[month][yearType(eyear)];
} else {
day += MONTH_START[month][yearType(eyear)];
}
}
return (int) (day + 347997);
}
/**
* {@inheritDoc}
* @stable ICU 3.8
*/
public String getType() {
return "hebrew";
}
/*
private static CalendarFactory factory;
public static CalendarFactory factory() {
if (factory == null) {
factory = new CalendarFactory() {
public Calendar create(TimeZone tz, ULocale loc) {
return new HebrewCalendar(tz, loc);
}
public String factoryName() {
return "Hebrew";
}
};
}
return factory;
}
*/
}