Class JapaneseChronology

All Implemented Interfaces:
Serializable, Comparable<Chronology>, Chronology 
public final class JapaneseChronology
extends AbstractChronology
implements Serializable

The Japanese Imperial calendar system.

This chronology defines the rules of the Japanese Imperial calendar system. This calendar system is primarily used in Japan. The Japanese Imperial calendar system is the same as the ISO calendar system apart from the era-based year numbering.

Japan introduced the Gregorian calendar starting with Meiji 6. Only Meiji and later eras are supported; dates before Meiji 6, January 1 are not supported.

The supported ChronoField instances are:

  • DAY_OF_WEEK
  • DAY_OF_MONTH
  • DAY_OF_YEAR
  • EPOCH_DAY
  • MONTH_OF_YEAR
  • PROLEPTIC_MONTH
  • YEAR_OF_ERA
  • YEAR
  • ERA
Implementation Requirements:
This class is immutable and thread-safe.
Since:
1.8
See Also:
Serialized Form

Field Summary

Fields
Modifier and Type Field Description
static JapaneseChronology INSTANCE

Singleton instance for Japanese chronology.

Method Summary

All Methods Instance Methods Concrete Methods
Modifier and Type Method Description
JapaneseDate date​(int prolepticYear, int month, int dayOfMonth)

Obtains a local date in Japanese calendar system from the proleptic-year, month-of-year and day-of-month fields.
JapaneseDate date​(Era era, int yearOfEra, int month, int dayOfMonth)

Obtains a local date in Japanese calendar system from the era, year-of-era, month-of-year and day-of-month fields.
JapaneseDate dateEpochDay​(long epochDay)

Obtains a local date in the Japanese calendar system from the epoch-day.
JapaneseDate dateYearDay​(int prolepticYear, int dayOfYear)

Obtains a local date in Japanese calendar system from the proleptic-year and day-of-year fields.
JapaneseDate dateYearDay​(Era era, int yearOfEra, int dayOfYear)

Obtains a local date in Japanese calendar system from the era, year-of-era and day-of-year fields.
JapaneseEra eraOf​(int eraValue)

Returns the calendar system era object from the given numeric value.
String getCalendarType()

Gets the calendar type of the underlying calendar system - 'japanese'.
String getId()

Gets the ID of the chronology - 'Japanese'.
boolean isLeapYear​(long prolepticYear)

Checks if the specified year is a leap year.

Methods declared in class java.time.chrono.AbstractChronology

compareTo, equals, hashCode, resolveDate, toString

Methods declared in class java.lang.Object

clone, finalize, getClass, notify, notifyAll, wait, wait, wait

Methods declared in interface java.time.chrono.Chronology

date, dateNow, dateNow, dateNow, epochSecond, epochSecond, eras, getDisplayName, localDateTime, period, prolepticYear, range, zonedDateTime, zonedDateTime

Field Detail

INSTANCE

public static final JapaneseChronology INSTANCE

Singleton instance for Japanese chronology.

Method Detail

getId

public String getId()

Gets the ID of the chronology - 'Japanese'.

The ID uniquely identifies the Chronology. It can be used to lookup the Chronology using Chronology.of(String).

Specified by:
getId in interface Chronology
Returns:
the chronology ID - 'Japanese'
See Also:
getCalendarType()

getCalendarType

public String getCalendarType()

Gets the calendar type of the underlying calendar system - 'japanese'.

The calendar type is an identifier defined by the Unicode Locale Data Markup Language (LDML) specification. It can be used to lookup the Chronology using Chronology.of(String). It can also be used as part of a locale, accessible via Locale.getUnicodeLocaleType(String) with the key 'ca'.

Specified by:
getCalendarType in interface Chronology
Returns:
the calendar system type - 'japanese'
See Also:
getId()

date

public JapaneseDate date​(Era era,
                         int yearOfEra,
                         int month,
                         int dayOfMonth)

Obtains a local date in Japanese calendar system from the era, year-of-era, month-of-year and day-of-month fields.

The Japanese month and day-of-month are the same as those in the ISO calendar system. They are not reset when the era changes. For example: 

6th Jan Showa 64 = ISO 1989-01-06
  7th Jan Showa 64 = ISO 1989-01-07
  8th Jan Heisei 1 = ISO 1989-01-08
  9th Jan Heisei 1 = ISO 1989-01-09
Specified by:
date in interface Chronology
Parameters:
era - the Japanese era, not null
yearOfEra - the year-of-era
month - the month-of-year
dayOfMonth - the day-of-month
Returns:
the Japanese local date, not null
Throws:
DateTimeException - if unable to create the date
ClassCastException - if the era is not a JapaneseEra

date

public JapaneseDate date​(int prolepticYear,
                         int month,
                         int dayOfMonth)

Obtains a local date in Japanese calendar system from the proleptic-year, month-of-year and day-of-month fields.

The Japanese proleptic year, month and day-of-month are the same as those in the ISO calendar system. They are not reset when the era changes.

Specified by:
date in interface Chronology
Parameters:
prolepticYear - the proleptic-year
month - the month-of-year
dayOfMonth - the day-of-month
Returns:
the Japanese local date, not null
Throws:
DateTimeException - if unable to create the date

dateYearDay

public JapaneseDate dateYearDay​(Era era,
                                int yearOfEra,
                                int dayOfYear)

Obtains a local date in Japanese calendar system from the era, year-of-era and day-of-year fields.

The day-of-year in this factory is expressed relative to the start of the year-of-era. This definition changes the normal meaning of day-of-year only in those years where the year-of-era is reset to one due to a change in the era. For example: 

6th Jan Showa 64 = day-of-year 6
  7th Jan Showa 64 = day-of-year 7
  8th Jan Heisei 1 = day-of-year 1
  9th Jan Heisei 1 = day-of-year 2
Specified by:
dateYearDay in interface Chronology
Parameters:
era - the Japanese era, not null
yearOfEra - the year-of-era
dayOfYear - the day-of-year
Returns:
the Japanese local date, not null
Throws:
DateTimeException - if unable to create the date
ClassCastException - if the era is not a JapaneseEra

dateYearDay

public JapaneseDate dateYearDay​(int prolepticYear,
                                int dayOfYear)

Obtains a local date in Japanese calendar system from the proleptic-year and day-of-year fields.

The day-of-year in this factory is expressed relative to the start of the proleptic year. The Japanese proleptic year and day-of-year are the same as those in the ISO calendar system. They are not reset when the era changes.

Specified by:
dateYearDay in interface Chronology
Parameters:
prolepticYear - the proleptic-year
dayOfYear - the day-of-year
Returns:
the Japanese local date, not null
Throws:
DateTimeException - if unable to create the date

dateEpochDay

public JapaneseDate dateEpochDay​(long epochDay)

Obtains a local date in the Japanese calendar system from the epoch-day.

Specified by:
dateEpochDay in interface Chronology
Parameters:
epochDay - the epoch day
Returns:
the Japanese local date, not null
Throws:
DateTimeException - if unable to create the date

isLeapYear

public boolean isLeapYear​(long prolepticYear)

Checks if the specified year is a leap year.

Japanese calendar leap years occur exactly in line with ISO leap years. This method does not validate the year passed in, and only has a well-defined result for years in the supported range.

Specified by:
isLeapYear in interface Chronology
Parameters:
prolepticYear - the proleptic-year to check, not validated for range
Returns:
true if the year is a leap year

eraOf

public JapaneseEra eraOf​(int eraValue)

Returns the calendar system era object from the given numeric value. See the description of each Era for the numeric values of: JapaneseEra.HEISEI, JapaneseEra.SHOWA,JapaneseEra.TAISHO, JapaneseEra.MEIJI), only Meiji and later eras are supported.

Specified by:
eraOf in interface Chronology
Parameters:
eraValue - the era value
Returns:
the Japanese Era for the given numeric era value
Throws:
DateTimeException - if eraValue is invalid