com.ibm.icu.util

Class JapaneseCalendar

Implemented Interfaces:
Cloneable, Comparable, Serializable

public class JapaneseCalendar
extends GregorianCalendar

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 1053 AD is era #0; however this may change in the future as we add more historical data. Use the predefined constants rather than using actual, absolute numbers.

This class should not be subclassed.

JapaneseCalendar usually should be instantiated using Calendar.getInstance(ULocale) passing in a ULocale with the tag "@calendar=japanese".

Authors:
Laura Werner
Alan Liu
See Also:
GregorianCalendar, Calendar

Field Summary

static int
CURRENT_ERA
static int
HEISEI
Constant for the era starting on Jan.
static int
MEIJI
Constant for the era starting on Sept.
static int
SHOWA
Constant for the era starting on Dec.
static int
TAISHO
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, JANUARY, JAN_1_1_JULIAN_DAY, JULIAN_DAY, JULY, JUNE, LEAST_MAXIMUM, MARCH, MAXIMUM, MAX_DATE, MAX_FIELD_COUNT, MAX_JULIAN, MAX_MILLIS, MAY, MILLISECOND, MILLISECONDS_IN_DAY, MINIMUM, MINIMUM_USER_STAMP, MINUTE, MIN_DATE, MIN_JULIAN, MIN_MILLIS, 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, WEDNESDAY, WEEKDAY, WEEKEND, WEEKEND_CEASE, WEEKEND_ONSET, WEEK_OF_MONTH, WEEK_OF_YEAR, YEAR, YEAR_WOY, ZONE_OFFSET

Constructor Summary

JapaneseCalendar()
Constructs a default JapaneseCalendar using the current time in the default time zone with the default locale.
JapaneseCalendar(Date date)
Constructs a JapaneseCalendar with the given date set in the default time zone with the default locale.
JapaneseCalendar(Locale aLocale)
Constructs a JapaneseCalendar based on the current time in the default time zone with the given locale.
JapaneseCalendar(TimeZone zone)
Constructs a JapaneseCalendar based on the current time in the given time zone with the default locale.
JapaneseCalendar(TimeZone zone, Locale aLocale)
Constructs a JapaneseCalendar based on the current time in the given time zone with the given locale.
JapaneseCalendar(TimeZone zone, ULocale locale)
Constructs a JapaneseCalendar based on the current time in the given time zone with the given locale.
JapaneseCalendar(ULocale locale)
Constructs a JapaneseCalendar based on the current time in the default time zone with the given locale.
JapaneseCalendar(int year, int month, int date)
Constructs a JapaneseCalendar with the given date set in the default time zone with the default locale.
JapaneseCalendar(int era, int year, int month, int date)
Constructs a JapaneseCalendar 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 a JapaneseCalendar with the given date and time set for the default time zone with the default locale.

Method Summary

String
getType()
Return the current Calendar type.
protected void
handleComputeFields(int julianDay)
protected int
handleGetExtendedYear()
protected int
handleGetLimit(int field, int limitType)
Override GregorianCalendar.

Methods inherited from class com.ibm.icu.util.GregorianCalendar

getActualMaximum, getActualMinimum, getGregorianChange, getType, handleComputeFields, handleComputeJulianDay, handleComputeMonthStart, handleGetExtendedYear, handleGetLimit, handleGetMonthLength, handleGetYearLength, hashCode, isEquivalentTo, isLeapYear, roll, setGregorianChange

Methods inherited from class com.ibm.icu.util.Calendar

add, after, before, clear, clear, clone, compareTo, compareTo, complete, computeFields, computeGregorianFields, computeGregorianMonthStart, computeJulianDay, computeMillisInDay, computeTime, computeZoneOffset, equals, fieldDifference, fieldName, floorDivide, floorDivide, floorDivide, floorDivide, get, getActualMaximum, getActualMinimum, getAvailableLocales, getAvailableULocales, getDateTimeFormat, getDateTimeFormat, getDayOfWeekType, getDisplayName, getDisplayName, getFieldCount, getFieldResolutionTable, getFirstDayOfWeek, getGreatestMinimum, getGregorianDayOfMonth, getGregorianDayOfYear, getGregorianMonth, getGregorianYear, getInstance, getInstance, getInstance, getInstance, getInstance, getInstance, getLeastMaximum, getLimit, getLocale, getMaximum, getMinimalDaysInFirstWeek, getMinimum, getStamp, getTime, getTimeInMillis, getTimeZone, getType, getWeekendTransition, gregorianMonthLength, gregorianPreviousMonthLength, handleComputeFields, handleComputeJulianDay, handleComputeMonthStart, handleCreateFields, handleGetDateFormat, handleGetDateFormat, handleGetExtendedYear, handleGetLimit, handleGetMonthLength, handleGetYearLength, hashCode, internalGet, internalGet, internalGetTimeInMillis, internalSet, isEquivalentTo, isGregorianLeapYear, isLenient, isSet, isWeekend, isWeekend, julianDayToDayOfWeek, julianDayToMillis, millisToJulianDay, newerField, newestStamp, pinField, prepareGetActual, resolveFields, roll, roll, set, set, set, set, setFirstDayOfWeek, setLenient, setMinimalDaysInFirstWeek, setTime, setTimeInMillis, setTimeZone, toString, validateField, validateField, validateFields, weekNumber, weekNumber

Field Details

CURRENT_ERA

public static final int CURRENT_ERA

HEISEI

public static final int HEISEI
Constant for the era starting on Jan. 7, 1989 AD.

MEIJI

public static final int MEIJI
Constant for the era starting on Sept. 8, 1868 AD.

SHOWA

public static final int SHOWA
Constant for the era starting on Dec. 25, 1926 AD.

TAISHO

public static final int TAISHO
Constant for the era starting on July 30, 1912 AD.

Constructor Details

JapaneseCalendar

public JapaneseCalendar()
Constructs a default JapaneseCalendar using the current time in the default time zone with the default locale.

JapaneseCalendar

public JapaneseCalendar(Date date)
Constructs a JapaneseCalendar 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.

JapaneseCalendar

public JapaneseCalendar(Locale aLocale)
Constructs a JapaneseCalendar based on the current time in the default time zone with the given locale.
Parameters:
aLocale - the given locale.

JapaneseCalendar

public JapaneseCalendar(TimeZone zone)
Constructs a JapaneseCalendar based on the current time in the given time zone with the default locale.
Parameters:
zone - the given time zone.

JapaneseCalendar

public JapaneseCalendar(TimeZone zone,
                        Locale aLocale)
Constructs a JapaneseCalendar based on the current time in the given time zone with the given locale.
Parameters:
zone - the given time zone.
aLocale - the given locale.

JapaneseCalendar

public JapaneseCalendar(TimeZone zone,
                        ULocale locale)
Constructs a JapaneseCalendar based on the current time in the given time zone with the given locale.
Parameters:
zone - the given time zone.
locale - the given ulocale.

JapaneseCalendar

public JapaneseCalendar(ULocale locale)
Constructs a JapaneseCalendar based on the current time in the default time zone with the given locale.
Parameters:
locale - the given ulocale.

JapaneseCalendar

public JapaneseCalendar(int year,
                        int month,
                        int date)
Constructs a JapaneseCalendar with the given date set in the default time zone with the default locale.
Parameters:
year - The value used to set the calendar's YEAR field, in the era Heisei, the most current at the time this class was last updated.
month - The value used to set the calendar's MONTH field. The value is 0-based. e.g., 0 for January.
date - The value used to set the calendar's DATE field.

JapaneseCalendar

public JapaneseCalendar(int era,
                        int year,
                        int month,
                        int date)
Constructs a JapaneseCalendar with the given date set in the default time zone with the default locale.
Parameters:
era - The imperial era used to set the calendar's ERA 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 constants MEIJI (which started in 1868 AD), TAISHO (1912 AD), SHOWA (1926 AD), and HEISEI (1989 AD).
year - The value used to set the calendar's YEAR field, in terms of the era.
month - The value used to set the calendar's MONTH field. The value is 0-based. e.g., 0 for January.
date - The value used to set the calendar's DATE field.

JapaneseCalendar

public JapaneseCalendar(int year,
                        int month,
                        int date,
                        int hour,
                        int minute,
                        int second)
Constructs a JapaneseCalendar 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's YEAR time field, in the era Heisei, the most current at the time of this writing.
month - The value used to set the calendar's MONTH time field. The value is 0-based. e.g., 0 for January.
date - The value used to set the calendar's DATE time field.
hour - The value used to set the calendar's HOUR_OF_DAY time field.
minute - The value used to set the calendar's MINUTE time field.
second - The value used to set the calendar's SECOND time field.

Method Details

getType

public String getType()
Return the current Calendar type.
Overrides:
getType in interface GregorianCalendar
Returns:
type of calendar (gregorian, etc.)

handleComputeFields

protected void handleComputeFields(int julianDay)
Overrides:
handleComputeFields in interface GregorianCalendar

handleGetExtendedYear

protected int handleGetExtendedYear()
Overrides:
handleGetExtendedYear in interface GregorianCalendar

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 interface GregorianCalendar

Copyright (c) 2006 IBM Corporation and others.