Package org.threeten.bp.chrono

Class JapaneseChronology

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

    Specification for implementors

    This class is immutable and thread-safe.
    See Also:
    Serialized Form

    • 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 class 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 class Chronology
        Returns:
        the calendar system type - 'japanese'
        See Also:
        getId()

      • date

        public JapaneseDate date​(Era era,
                         int yearOfEra,
                         int month,
                         int dayOfMonth)
        Description copied from class: Chronology
        Obtains a local date in this chronology from the era, year-of-era, month-of-year and day-of-month fields.
        Overrides:
        date in class Chronology
        Parameters:
        era - the era of the correct type for the chronology, not null
        yearOfEra - the chronology year-of-era
        month - the chronology month-of-year
        dayOfMonth - the chronology day-of-month
        Returns:
        the local date in this chronology, not null

      • date

        public JapaneseDate date​(int prolepticYear,
                         int month,
                         int dayOfMonth)
        Description copied from class: Chronology
        Obtains a local date in this chronology from the proleptic-year, month-of-year and day-of-month fields.
        Specified by:
        date in class Chronology
        Parameters:
        prolepticYear - the chronology proleptic-year
        month - the chronology month-of-year
        dayOfMonth - the chronology day-of-month
        Returns:
        the local date in this chronology, not null

      • 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
        Overrides:
        dateYearDay in class 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 class 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)
        Description copied from class: Chronology
        Obtains a local date in this chronology from the epoch-day.

        The definition of EPOCH_DAY is the same for all calendar systems, thus it can be used for conversion.

        Specified by:
        dateEpochDay in class Chronology
        Parameters:
        epochDay - the epoch day
        Returns:
        the local date in this chronology, not null

      • date

        public JapaneseDate date​(TemporalAccessor temporal)
        Description copied from class: Chronology
        Obtains a local date in this chronology from another temporal object.

        This creates a date in this chronology based on the specified TemporalAccessor.

        The standard mechanism for conversion between date types is the local epoch-day field.

        Specified by:
        date in class Chronology
        Parameters:
        temporal - the temporal object to convert, not null
        Returns:
        the local date in this chronology, not null

      • localDateTime

        public ChronoLocalDateTime<JapaneseDate> localDateTime​(TemporalAccessor temporal)
        Description copied from class: Chronology
        Obtains a local date-time in this chronology from another temporal object.

        This creates a date-time in this chronology based on the specified TemporalAccessor.

        The date of the date-time should be equivalent to that obtained by calling Chronology.date(TemporalAccessor). The standard mechanism for conversion between time types is the nano-of-day field.

        Overrides:
        localDateTime in class Chronology
        Parameters:
        temporal - the temporal object to convert, not null
        Returns:
        the local date-time in this chronology, not null

      • zonedDateTime

        public ChronoZonedDateTime<JapaneseDate> zonedDateTime​(TemporalAccessor temporal)
        Description copied from class: Chronology
        Obtains a zoned date-time in this chronology from another temporal object.

        This creates a date-time in this chronology based on the specified TemporalAccessor.

        This should obtain a ZoneId using ZoneId.from(TemporalAccessor). The date-time should be obtained by obtaining an Instant. If that fails, the local date-time should be used.

        Overrides:
        zonedDateTime in class Chronology
        Parameters:
        temporal - the temporal object to convert, not null
        Returns:
        the zoned date-time in this chronology, not null

      • zonedDateTime

        public ChronoZonedDateTime<JapaneseDate> zonedDateTime​(Instant instant,
                                                       ZoneId zone)
        Description copied from class: Chronology
        Obtains a zoned date-time in this chronology from an Instant.

        This creates a zoned date-time with the same instant as that specified.

        Overrides:
        zonedDateTime in class Chronology
        Parameters:
        instant - the instant to create the date-time from, not null
        zone - the time-zone, not null
        Returns:
        the zoned date-time, not null

      • dateNow

        public JapaneseDate dateNow()
        Description copied from class: Chronology
        Obtains the current local date in this chronology from the system clock in the default time-zone.

        This will query the system clock in the default time-zone to obtain the current date.

        Using this method will prevent the ability to use an alternate clock for testing because the clock is hard-coded.

        This implementation uses Chronology.dateNow(Clock).

        Overrides:
        dateNow in class Chronology
        Returns:
        the current local date using the system clock and default time-zone, not null

      • dateNow

        public JapaneseDate dateNow​(ZoneId zone)
        Description copied from class: Chronology
        Obtains the current local date in this chronology from the system clock in the specified time-zone.

        This will query the system clock to obtain the current date. Specifying the time-zone avoids dependence on the default time-zone.

        Using this method will prevent the ability to use an alternate clock for testing because the clock is hard-coded.

        Overrides:
        dateNow in class Chronology
        Parameters:
        zone - the zone ID to use, not null
        Returns:
        the current local date using the system clock, not null

      • dateNow

        public JapaneseDate dateNow​(Clock clock)
        Description copied from class: Chronology
        Obtains the current local date in this chronology from the specified clock.

        This will query the specified clock to obtain the current date - today. Using this method allows the use of an alternate clock for testing. The alternate clock may be introduced using dependency injection.

        Overrides:
        dateNow in class Chronology
        Parameters:
        clock - the clock to use, not null
        Returns:
        the current local date, not null

      • 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 class Chronology
        Parameters:
        prolepticYear - the proleptic-year to check, not validated for range
        Returns:
        true if the year is a leap year

      • prolepticYear

        public int prolepticYear​(Era era,
                         int yearOfEra)
        Description copied from class: Chronology
        Calculates the proleptic-year given the era and year-of-era.

        This combines the era and year-of-era into the single proleptic-year field.

        Specified by:
        prolepticYear in class Chronology
        Parameters:
        era - the era of the correct type for the chronology, not null
        yearOfEra - the chronology year-of-era
        Returns:
        the proleptic-year

      • eras

        public List<Era> eras()
        Description copied from class: Chronology
        Gets the list of eras for the chronology.

        Most calendar systems have an era, within which the year has meaning. If the calendar system does not support the concept of eras, an empty list must be returned.

        Specified by:
        eras in class Chronology
        Returns:
        the list of eras for the chronology, may be immutable, not null

      • range

        public ValueRange range​(ChronoField field)
        Description copied from class: Chronology
        Gets the range of valid values for the specified field.

        All fields can be expressed as a long integer. This method returns an object that describes the valid range for that value.

        Note that the result only describes the minimum and maximum valid values and it is important not to read too much into them. For example, there could be values within the range that are invalid for the field.

        This method will return a result whether or not the chronology supports the field.

        Specified by:
        range in class Chronology
        Parameters:
        field - the field to get the range for, not null
        Returns:
        the range of valid values for the field, not null

      • resolveDate

        public JapaneseDate resolveDate​(Map<TemporalField,​Long> fieldValues,
                                ResolverStyle resolverStyle)
        Description copied from class: Chronology
        Resolves parsed ChronoField values into a date during parsing.

        Most TemporalField implementations are resolved using the resolve method on the field. By contrast, the ChronoField class defines fields that only have meaning relative to the chronology. As such, ChronoField date fields are resolved here in the context of a specific chronology.

        The default implementation, which explains typical resolve behaviour, is provided in AbstractChronology.

        Specified by:
        resolveDate in class Chronology
        Parameters:
        fieldValues - the map of fields to values, which can be updated, not null
        resolverStyle - the requested type of resolve, not null
        Returns:
        the resolved date, null if insufficient information to create a date