Class JapaneseCalendar
- All Implemented Interfaces:
Serializable
,Cloneable
,Comparable<Calendar>
JapaneseCalendar
is a subclass of GregorianCalendar
that numbers years and eras based on the reigns of the Japanese emperors.
The Japanese calendar is identical to the Gregorian calendar in all respects
except for the year and era. The ascension of each emperor to the throne
begins a new era, and the years of that era are numbered starting with the
year of ascension as year 1.
Note that in the year of an imperial ascension, there are two possible sets of year and era values: that for the old era and for the new. For example, a new era began on January 7, 1989 AD. Strictly speaking, the first six days of that year were in the Showa era, e.g. "January 6, 64 Showa", while the rest of the year was in the Heisei era, e.g. "January 7, 1 Heisei". This class handles this distinction correctly when computing dates. However, in lenient mode either form of date is acceptable as input.
In modern times, eras have started on January 8, 1868 AD, Gregorian (Meiji),
July 30, 1912 (Taisho), December 25, 1926 (Showa), and January 7, 1989 (Heisei). Constants
for these eras, suitable for use in the ERA
field, are provided
in this class. Note that the number used for each era is more or
less arbitrary. Currently, the era starting in 645 AD is era #0; however this
may change in the future. Use the predefined constants rather than using actual,
absolute numbers.
Since ICU4J 63, start date of each era is imported from CLDR. CLDR era data may contain tentative era in near future with placeholder names. By default, such era data is not enabled. ICU4J users who want to test the behavior of the future era can enable this by one of following settings (in the priority order):
- Java system property
ICU_ENABLE_TENTATIVE_ERA=true
. - Environment variable
ICU_ENABLE_TENTATIVE_ERA=true
. - Java system property
jdk.calendar.japanese.supplemental.era=xxx
. (Note: This configuration is used for specifying a new era's start date and names in OpenJDK. ICU4J implementation enables the CLDR tentative era when this property is defined, but it does not use the start date and names specified by the property value.)
This class should not be subclassed.
JapaneseCalendar usually should be instantiated using
Calendar.getInstance(ULocale)
passing in a ULocale
with the tag "@calendar=japanese"
.
- Author:
- Laura Werner, Alan Liu
- See Also:
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Nested Class Summary
Nested classes/interfaces inherited from class com.ibm.icu.util.Calendar
Calendar.FormatConfiguration, Calendar.WeekData
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Field Summary
FieldsModifier and TypeFieldDescriptionstatic final int
static final int
Constant for the era starting on Jan. 7, 1989 AD.static final int
Constant for the era starting on Sept. 8, 1868 AD.static final int
Constant for the era starting on May 1, 2019 AD.static final int
Constant for the era starting on Dec. 25, 1926 AD.static final int
Constant for the era starting on July 30, 1912 AD.Fields inherited from class com.ibm.icu.util.GregorianCalendar
AD, BC, invertGregorian, isGregorian
Fields inherited from class com.ibm.icu.util.Calendar
AM, AM_PM, APRIL, AUGUST, BASE_FIELD_COUNT, DATE, DAY_OF_MONTH, DAY_OF_WEEK, DAY_OF_WEEK_IN_MONTH, DAY_OF_YEAR, DECEMBER, DOW_LOCAL, DST_OFFSET, EPOCH_JULIAN_DAY, ERA, EXTENDED_YEAR, FEBRUARY, FRIDAY, GREATEST_MINIMUM, HOUR, HOUR_OF_DAY, INTERNALLY_SET, IS_LEAP_MONTH, JAN_1_1_JULIAN_DAY, JANUARY, JULIAN_DAY, JULY, JUNE, LEAST_MAXIMUM, MARCH, MAX_DATE, MAX_FIELD_COUNT, MAX_JULIAN, MAX_MILLIS, MAXIMUM, MAY, MILLISECOND, MILLISECONDS_IN_DAY, MIN_DATE, MIN_JULIAN, MIN_MILLIS, MINIMUM, MINIMUM_USER_STAMP, MINUTE, MONDAY, MONTH, NOVEMBER, OCTOBER, ONE_DAY, ONE_HOUR, ONE_MINUTE, ONE_SECOND, ONE_WEEK, PM, RESOLVE_REMAP, SATURDAY, SECOND, SEPTEMBER, SUNDAY, THURSDAY, TUESDAY, UNDECIMBER, UNSET, WALLTIME_FIRST, WALLTIME_LAST, WALLTIME_NEXT_VALID, WEDNESDAY, WEEK_OF_MONTH, WEEK_OF_YEAR, WEEKDAY, WEEKEND, WEEKEND_CEASE, WEEKEND_ONSET, YEAR, YEAR_WOY, ZONE_OFFSET
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Constructor Summary
ConstructorsConstructorDescriptionConstructs a defaultJapaneseCalendar
using the current time in the default time zone with the default locale.JapaneseCalendar
(int year, int month, int date) Constructs aJapaneseCalendar
with the given date set in the default time zone with the default locale.JapaneseCalendar
(int era, int year, int month, int date) Constructs aJapaneseCalendar
with the given date set in the default time zone with the default locale.JapaneseCalendar
(int year, int month, int date, int hour, int minute, int second) Constructs aJapaneseCalendar
with the given date and time set for the default time zone with the default locale.JapaneseCalendar
(TimeZone zone) Constructs aJapaneseCalendar
based on the current time in the given time zone with the default locale.JapaneseCalendar
(TimeZone zone, ULocale locale) Constructs aJapaneseCalendar
based on the current time in the given time zone with the given locale.JapaneseCalendar
(TimeZone zone, Locale aLocale) Constructs aJapaneseCalendar
based on the current time in the given time zone with the given locale.JapaneseCalendar
(ULocale locale) Constructs aJapaneseCalendar
based on the current time in the default time zone with the given locale.JapaneseCalendar
(Date date) Constructs aJapaneseCalendar
with the given date set in the default time zone with the default locale.JapaneseCalendar
(Locale aLocale) Constructs aJapaneseCalendar
based on the current time in the default time zone with the given locale. -
Method Summary
Modifier and TypeMethodDescriptionstatic boolean
Deprecated.This API is ICU internal only.int
getActualMaximum
(int field) Return the maximum value that this field could have, given the current date.protected int
getDefaultDayInMonth
(int extendedYear, int month) Called by handleComputeJulianDay.protected int
getDefaultMonthInYear
(int extendedYear) Called by handleComputeJulianDay.getType()
Returns the calendar type name string for this Calendar object.protected void
handleComputeFields
(int julianDay) Override Calendar to compute several fields specific to the hybrid Gregorian-Julian calendar system.protected int
Returns the extended year defined by the current fields.protected int
handleGetLimit
(int field, int limitType) Override GregorianCalendar.boolean
Deprecated.This API is ICU internal only.Methods inherited from class com.ibm.icu.util.GregorianCalendar
getActualMinimum, getGregorianChange, handleComputeJulianDay, handleComputeMonthStart, handleGetMonthLength, handleGetYearLength, hashCode, isEquivalentTo, isLeapYear, roll, setGregorianChange
Methods inherited from class com.ibm.icu.util.Calendar
add, after, before, clear, clear, clone, compareTo, complete, computeFields, computeGregorianFields, computeGregorianMonthStart, computeJulianDay, computeMillisInDay, computeMillisInDayLong, computeTime, computeZoneOffset, computeZoneOffset, equals, fieldDifference, fieldName, floorDivide, floorDivide, floorDivide, floorDivide, get, getAvailableLocales, getAvailableULocales, getDateAtTimePattern, getDateTimeFormat, getDateTimeFormat, getDateTimePattern, getDayOfWeekType, getDisplayName, getDisplayName, getFieldCount, getFieldResolutionTable, getFirstDayOfWeek, getGreatestMinimum, getGregorianDayOfMonth, getGregorianDayOfYear, getGregorianMonth, getGregorianYear, getInstance, getInstance, getInstance, getInstance, getInstance, getInstance, getKeywordValuesForLocale, getLeastMaximum, getLimit, getLocale, getMaximum, getMinimalDaysInFirstWeek, getMinimum, getRelatedYear, getRepeatedWallTimeOption, getSkippedWallTimeOption, getStamp, getTime, getTimeInMillis, getTimeZone, getWeekData, getWeekDataForRegion, getWeekendTransition, gregorianMonthLength, gregorianPreviousMonthLength, handleCreateFields, handleGetDateFormat, handleGetDateFormat, handleGetDateFormat, handleGetDateFormat, internalGet, internalGet, internalGetTimeInMillis, internalSet, isGregorianLeapYear, isLenient, isSet, isWeekend, isWeekend, julianDayToDayOfWeek, julianDayToMillis, millisToJulianDay, newerField, newestStamp, pinField, prepareGetActual, resolveFields, roll, set, set, set, set, setFirstDayOfWeek, setLenient, setMinimalDaysInFirstWeek, setRelatedYear, setRepeatedWallTimeOption, setSkippedWallTimeOption, setTime, setTimeInMillis, setTimeZone, setWeekData, toString, validateField, validateField, validateFields, weekNumber, weekNumber
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Field Details
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CURRENT_ERA
public static final int CURRENT_ERA -
MEIJI
public static final int MEIJIConstant for the era starting on Sept. 8, 1868 AD. -
TAISHO
public static final int TAISHOConstant for the era starting on July 30, 1912 AD. -
SHOWA
public static final int SHOWAConstant for the era starting on Dec. 25, 1926 AD. -
HEISEI
public static final int HEISEIConstant for the era starting on Jan. 7, 1989 AD. -
REIWA
public static final int REIWAConstant for the era starting on May 1, 2019 AD.
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Constructor Details
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JapaneseCalendar
public JapaneseCalendar()Constructs a defaultJapaneseCalendar
using the current time in the default time zone with the default locale. -
JapaneseCalendar
Constructs aJapaneseCalendar
based on the current time in the given time zone with the default locale.- Parameters:
zone
- the given time zone.
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JapaneseCalendar
Constructs aJapaneseCalendar
based on the current time in the default time zone with the given locale.- Parameters:
aLocale
- the given locale.
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JapaneseCalendar
Constructs aJapaneseCalendar
based on the current time in the default time zone with the given locale.- Parameters:
locale
- the given ulocale.
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JapaneseCalendar
Constructs aJapaneseCalendar
based on the current time in the given time zone with the given locale.- Parameters:
zone
- the given time zone.aLocale
- the given locale.
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JapaneseCalendar
Constructs aJapaneseCalendar
based on the current time in the given time zone with the given locale.- Parameters:
zone
- the given time zone.locale
- the given ulocale.
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JapaneseCalendar
Constructs aJapaneseCalendar
with the given date set in the default time zone with the default locale.- Parameters:
date
- The date to which the new calendar is set.
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JapaneseCalendar
public JapaneseCalendar(int era, int year, int month, int date) Constructs aJapaneseCalendar
with the given date set in the default time zone with the default locale.- Parameters:
era
- The imperial era used to set the calendar'sERA
field. Eras are numbered starting with the Tenki era, which began in 1053 AD Gregorian, as era zero. Recent eras can be specified using the constantsMEIJI
(which started in 1868 AD),TAISHO
(1912 AD),SHOWA
(1926 AD), andHEISEI
(1989 AD).year
- The value used to set the calendar'sYEAR
field, in terms of the era.month
- The value used to set the calendar'sMONTH
field. The value is 0-based. e.g., 0 for January.date
- The value used to set the calendar's DATE field.
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JapaneseCalendar
public JapaneseCalendar(int year, int month, int date) Constructs aJapaneseCalendar
with the given date set in the default time zone with the default locale.- Parameters:
year
- The value used to set the calendar'sYEAR
field, in the era Heisei, the most current at the time this class was last updated.month
- The value used to set the calendar'sMONTH
field. The value is 0-based. e.g., 0 for January.date
- The value used to set the calendar'sDATE
field.
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JapaneseCalendar
public JapaneseCalendar(int year, int month, int date, int hour, int minute, int second) Constructs aJapaneseCalendar
with the given date and time set for the default time zone with the default locale.- Parameters:
year
- The value used to set the calendar'sYEAR
time field, in the era Heisei, the most current at the time of this writing.month
- The value used to set the calendar'sMONTH
time field. The value is 0-based. e.g., 0 for January.date
- The value used to set the calendar'sDATE
time field.hour
- The value used to set the calendar'sHOUR_OF_DAY
time field.minute
- The value used to set the calendar'sMINUTE
time field.second
- The value used to set the calendar'sSECOND
time field.
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Method Details
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enableTentativeEra
Deprecated.This API is ICU internal only.Check environment variable that enables use of future eras. -
handleGetExtendedYear
protected int handleGetExtendedYear()Description copied from class:Calendar
Returns the extended year defined by the current fields. This will use the EXTENDED_YEAR field or the YEAR and supra-year fields (such as ERA) specific to the calendar system, depending on which set of fields is newer.- Overrides:
handleGetExtendedYear
in classGregorianCalendar
- Returns:
- the extended year
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getDefaultMonthInYear
protected int getDefaultMonthInYear(int extendedYear) Called by handleComputeJulianDay. Returns the default month (0-based) for the year, taking year and era into account. Defaults to 0 (JANUARY) for Gregorian.- Overrides:
getDefaultMonthInYear
in classCalendar
- Parameters:
extendedYear
- the extendedYear, as returned by handleGetExtendedYear- Returns:
- the default month
- See Also:
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getDefaultDayInMonth
protected int getDefaultDayInMonth(int extendedYear, int month) Called by handleComputeJulianDay. Returns the default day (1-based) for the month, taking currently-set year and era into account. Defaults to 1 for Gregorian.- Overrides:
getDefaultDayInMonth
in classCalendar
- Parameters:
extendedYear
- the extendedYear, as returned by handleGetExtendedYearmonth
- the month, as returned by getDefaultMonthInYear- Returns:
- the default day of the month
- See Also:
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handleComputeFields
protected void handleComputeFields(int julianDay) Description copied from class:GregorianCalendar
Override Calendar to compute several fields specific to the hybrid Gregorian-Julian calendar system. These are:- ERA
- YEAR
- MONTH
- DAY_OF_MONTH
- DAY_OF_YEAR
- EXTENDED_YEAR
- Overrides:
handleComputeFields
in classGregorianCalendar
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handleGetLimit
protected int handleGetLimit(int field, int limitType) Override GregorianCalendar. We should really handle YEAR_WOY and EXTENDED_YEAR here too to implement the 1..5000000 range, but it's not critical.- Overrides:
handleGetLimit
in classGregorianCalendar
- Parameters:
field
- one of the above field numberslimitType
- one ofMINIMUM
,GREATEST_MINIMUM
,LEAST_MAXIMUM
, orMAXIMUM
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getType
Returns the calendar type name string for this Calendar object. The returned string is the legacy ICU calendar attribute value, for example, "gregorian" or "japanese".See type="old type name" for the calendar attribute of locale IDs at http://www.unicode.org/reports/tr35/#Key_Type_Definitions
- Overrides:
getType
in classGregorianCalendar
- Returns:
- legacy calendar type name string
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haveDefaultCentury
Deprecated.This API is ICU internal only.Returns if two digit representation of year in this calendar type customarily implies a default century (i.e. 03 -> 2003). The default implementation returnstrue
. A subclass may returnfalse
if such practice is not applicable (for example, Chinese calendar and Japanese calendar).- Overrides:
haveDefaultCentury
in classCalendar
- Returns:
true
if this calendar has a default century.
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getActualMaximum
public int getActualMaximum(int field) Return the maximum value that this field could have, given the current date. For example, with the date "Feb 3, 1997" and the DAY_OF_MONTH field, the actual maximum would be 28; for "Feb 3, 1996" it s 29. Similarly for a Hebrew calendar, for some years the actual maximum for MONTH is 12, and for others 13.- Overrides:
getActualMaximum
in classGregorianCalendar
- Parameters:
field
- the field whose maximum is desired- Returns:
- the maximum of the given field for the current date of this calendar
- See Also:
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