com.ibm.icu.util
Class JapaneseCalendar

java.lang.Object
  extended by com.ibm.icu.util.Calendar
      extended by com.ibm.icu.util.GregorianCalendar
          extended by com.ibm.icu.util.JapaneseCalendar
All Implemented Interfaces:
Serializable, Cloneable, Comparable

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".

Author:
Laura Werner, Alan Liu
See Also:
GregorianCalendar, Calendar, Serialized Form
Status:
Stable ICU 2.8.

Nested Class Summary
 
Nested classes/interfaces inherited from class com.ibm.icu.util.Calendar
Calendar.FormatConfiguration
 
Field Summary
static int CURRENT_ERA
           
static int HEISEI
          Constant for the era starting on Jan. 7, 1989 AD.
static int MEIJI
          Constant for the era starting on Sept. 8, 1868 AD.
static int SHOWA
          Constant for the era starting on Dec. 25, 1926 AD.
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, 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, WEDNESDAY, WEEK_OF_MONTH, WEEK_OF_YEAR, WEEKDAY, WEEKEND, WEEKEND_CEASE, WEEKEND_ONSET, 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(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.
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.
 
Method Summary
 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.
 String getType()
          Return the current Calendar type.
protected  void handleComputeFields(int julianDay)
          Override Calendar to compute several fields specific to the hybrid Gregorian-Julian calendar system.
protected  int handleGetExtendedYear()
          Return the extended year defined by the current fields.
protected  int handleGetLimit(int field, int limitType)
          Override GregorianCalendar.
 
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, compareTo, complete, computeFields, computeGregorianFields, computeGregorianMonthStart, computeJulianDay, computeMillisInDay, computeTime, computeZoneOffset, equals, fieldDifference, fieldName, floorDivide, floorDivide, floorDivide, floorDivide, get, 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, getWeekendTransition, gregorianMonthLength, gregorianPreviousMonthLength, handleCreateFields, 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, setTime, setTimeInMillis, setTimeZone, toString, validateField, validateField, validateFields, weekNumber, weekNumber
 
Methods inherited from class java.lang.Object
finalize, getClass, notify, notifyAll, wait, wait, wait
 

Field Detail

CURRENT_ERA

public static final int CURRENT_ERA
Status:
Stable ICU 2.8.

MEIJI

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

Status:
Stable ICU 2.8.

TAISHO

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

Status:
Stable ICU 2.8.

SHOWA

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

Status:
Stable ICU 2.8.

HEISEI

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

Status:
Stable ICU 2.8.
Constructor Detail

JapaneseCalendar

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

Status:
Stable ICU 2.8.

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.
Status:
Stable ICU 2.8.

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.
Status:
Stable ICU 2.8.

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.
Status:
Stable ICU 3.2.

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.
Status:
Stable ICU 2.8.

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.
Status:
Stable ICU 3.2.

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.
Status:
Stable ICU 2.8.

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.
Status:
Stable ICU 2.8.

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.
Status:
Stable ICU 2.8.

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.
Status:
Stable ICU 2.8.
Method Detail

handleGetExtendedYear

protected int handleGetExtendedYear()
Description copied from class: Calendar
Return 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 class GregorianCalendar
Returns:
the extended year
Status:
Stable ICU 2.8.

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 class Calendar
Parameters:
extendedYear - the extendedYear, as returned by handleGetExtendedYear
Returns:
the default month
See Also:
Calendar.MONTH
Status:
Draft ICU 3.6.

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 class Calendar
Parameters:
extendedYear - the extendedYear, as returned by handleGetExtendedYear
month - the month, as returned by getDefaultMonthInYear
Returns:
the default day of the month
See Also:
Calendar.DAY_OF_MONTH
Status:
Draft ICU 3.6.

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:

Overrides:
handleComputeFields in class GregorianCalendar
Status:
Stable ICU 2.8.

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 class GregorianCalendar
Parameters:
field - one of the above field numbers
limitType - one of MINIMUM, GREATEST_MINIMUM, LEAST_MAXIMUM, or MAXIMUM
Status:
Stable ICU 2.8.

getType

public String getType()
Return the current Calendar type.

Overrides:
getType in class GregorianCalendar
Returns:
type of calendar
Status:
Stable ICU 3.8.

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 class GregorianCalendar
Parameters:
field - the field whose maximum is desired
Returns:
the maximum of the given field for the current date of this calendar
See Also:
Calendar.getMaximum(int), Calendar.getLeastMaximum(int)
Status:
Draft ICU 4.0.


Copyright (c) 2009 IBM Corporation and others.