Class JapaneseChronology
- java.lang.Object
-
- java.time.chrono.AbstractChronology
-
- java.time.chrono.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
Fields
Modifier and Type | Field and Description |
---|---|
static JapaneseChronology |
INSTANCE Singleton instance for Japanese chronology. |
Methods
Modifier and Type | Method and Description |
---|---|
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 |
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(TemporalAccessor temporal) Obtains a local date in this chronology from another temporal object. |
JapaneseDate |
dateEpochDay(long epochDay) Obtains a local date in the Japanese calendar system from the epoch-day. |
JapaneseDate |
dateNow() Obtains the current local date in this chronology from the system clock in the default time-zone. |
JapaneseDate |
dateNow(Clock clock) Obtains the current local date in this chronology from the specified clock. |
JapaneseDate |
dateNow(ZoneId zone) Obtains the current local date in this chronology from the system clock in the specified time-zone. |
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. |
JapaneseDate |
dateYearDay(int prolepticYear,
int dayOfYear) Obtains a local date in Japanese calendar system from the proleptic-year and day-of-year fields. |
JapaneseEra |
eraOf(int eraValue) Returns the calendar system era object from the given numeric value. |
List<Era> |
eras() Gets the list of eras for the chronology. |
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. |
ChronoLocalDateTime<JapaneseDate> |
localDateTime(TemporalAccessor temporal) Obtains a local date-time in this chronology from another temporal object. |
int |
prolepticYear(Era era,
int yearOfEra) Calculates the proleptic-year given the era and year-of-era. |
ValueRange |
range(ChronoField field) Gets the range of valid values for the specified field. |
JapaneseDate |
resolveDate(Map<TemporalField,Long> fieldValues,
ResolverStyle resolverStyle) Resolves parsed |
ChronoZonedDateTime<JapaneseDate> |
zonedDateTime(Instant instant,
ZoneId zone) Obtains a |
ChronoZonedDateTime<JapaneseDate> |
zonedDateTime(TemporalAccessor temporal) Obtains a |
Methods inherited from class java.time.chrono.AbstractChronology
compareTo, equals, hashCode, toString
Methods inherited from class java.lang.Object
clone, finalize, getClass, notify, notifyAll, wait, wait, wait
Methods inherited from interface java.time.chrono.Chronology
from, getDisplayName, period
Fields
INSTANCE
public static final JapaneseChronology INSTANCE
Singleton instance for Japanese chronology.
Methods
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 interfaceChronology
- 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 interfaceChronology
- 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 interfaceChronology
- 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 theera
is not aJapaneseEra
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 interfaceChronology
- 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 interfaceChronology
- 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 theera
is not aJapaneseEra
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 interfaceChronology
- 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 interfaceChronology
- Parameters:
-
epochDay
- the epoch day - Returns:
- the Japanese local date, not null
- Throws:
-
DateTimeException
- if unable to create the date
dateNow
public JapaneseDate dateNow()
Description copied from interface: 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.
- Specified by:
-
dateNow
in interfaceChronology
- Returns:
- the current local date using the system clock and default time-zone, not null
dateNow
public JapaneseDate dateNow(ZoneId zone)
Description copied from interface: 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.
- Specified by:
-
dateNow
in interfaceChronology
- 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 interface: 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
.
- Specified by:
-
dateNow
in interfaceChronology
- Parameters:
-
clock
- the clock to use, not null - Returns:
- the current local date, not null
date
public JapaneseDate date(TemporalAccessor temporal)
Description copied from interface: Chronology
Obtains a local date in this chronology from another temporal object.
This obtains a date in this chronology based on the specified temporal. A TemporalAccessor
represents an arbitrary set of date and time information, which this factory converts to an instance of ChronoLocalDate
.
The conversion typically uses the EPOCH_DAY
field, which is standardized across calendar systems.
This method matches the signature of the functional interface TemporalQuery
allowing it to be used as a query via method reference, aChronology::date
.
- Specified by:
-
date
in interfaceChronology
- Parameters:
-
temporal
- the temporal object to convert, not null - Returns:
- the local date in this chronology, not null
- See Also:
ChronoLocalDate.from(TemporalAccessor)
localDateTime
public ChronoLocalDateTime<JapaneseDate> localDateTime(TemporalAccessor temporal)
Description copied from interface: Chronology
Obtains a local date-time in this chronology from another temporal object.
This obtains a date-time in this chronology based on the specified temporal. A TemporalAccessor
represents an arbitrary set of date and time information, which this factory converts to an instance of ChronoLocalDateTime
.
The conversion extracts and combines the ChronoLocalDate
and the LocalTime
from the temporal object. Implementations are permitted to perform optimizations such as accessing those fields that are equivalent to the relevant objects. The result uses this chronology.
This method matches the signature of the functional interface TemporalQuery
allowing it to be used as a query via method reference, aChronology::localDateTime
.
- Specified by:
-
localDateTime
in interfaceChronology
- Parameters:
-
temporal
- the temporal object to convert, not null - Returns:
- the local date-time in this chronology, not null
- See Also:
ChronoLocalDateTime.from(TemporalAccessor)
zonedDateTime
public ChronoZonedDateTime<JapaneseDate> zonedDateTime(TemporalAccessor temporal)
Description copied from interface: Chronology
Obtains a ChronoZonedDateTime
in this chronology from another temporal object.
This obtains a zoned date-time in this chronology based on the specified temporal. A TemporalAccessor
represents an arbitrary set of date and time information, which this factory converts to an instance of ChronoZonedDateTime
.
The conversion will first obtain a ZoneId
from the temporal object, falling back to a ZoneOffset
if necessary. It will then try to obtain an Instant
, falling back to a ChronoLocalDateTime
if necessary. The result will be either the combination of ZoneId
or ZoneOffset
with Instant
or ChronoLocalDateTime
. Implementations are permitted to perform optimizations such as accessing those fields that are equivalent to the relevant objects. The result uses this chronology.
This method matches the signature of the functional interface TemporalQuery
allowing it to be used as a query via method reference, aChronology::zonedDateTime
.
- Specified by:
-
zonedDateTime
in interfaceChronology
- Parameters:
-
temporal
- the temporal object to convert, not null - Returns:
- the zoned date-time in this chronology, not null
- See Also:
ChronoZonedDateTime.from(TemporalAccessor)
zonedDateTime
public ChronoZonedDateTime<JapaneseDate> zonedDateTime(Instant instant, ZoneId zone)
Description copied from interface: Chronology
Obtains a ChronoZonedDateTime
in this chronology from an Instant
.
This obtains a zoned date-time with the same instant as that specified.
- Specified by:
-
zonedDateTime
in interfaceChronology
- 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
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 interfaceChronology
- 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 interface: 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.
If the chronology makes active use of eras, such as JapaneseChronology
then the year-of-era will be validated against the era. For other chronologies, validation is optional.
- Specified by:
-
prolepticYear
in interfaceChronology
- Parameters:
-
era
- the era of the correct type for the chronology, not null -
yearOfEra
- the chronology year-of-era - Returns:
- the proleptic-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 interfaceChronology
- Parameters:
-
eraValue
- the era value - Returns:
- the Japanese
Era
for the given numeric era value - Throws:
-
DateTimeException
- iferaValue
is invalid
eras
public List<Era> eras()
Description copied from interface: 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 interfaceChronology
- Returns:
- the list of eras for the chronology, may be immutable, not null
range
public ValueRange range(ChronoField field)
Description copied from interface: 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 interfaceChronology
- 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: AbstractChronology
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.
ChronoField
instances are resolved by this method, which may be overridden in subclasses.
-
EPOCH_DAY
- If present, this is converted to a date and all other date fields are then cross-checked against the date. -
PROLEPTIC_MONTH
- If present, then it is split into theYEAR
andMONTH_OF_YEAR
. If the mode is strict or smart then the field is validated. -
YEAR_OF_ERA
andERA
- If both are present, then they are combined to form aYEAR
. In lenient mode, theYEAR_OF_ERA
range is not validated, in smart and strict mode it is. TheERA
is validated for range in all three modes. If only theYEAR_OF_ERA
is present, and the mode is smart or lenient, then the last available era is assumed. In strict mode, no era is assumed and theYEAR_OF_ERA
is left untouched. If only theERA
is present, then it is left untouched. -
YEAR
,MONTH_OF_YEAR
andDAY_OF_MONTH
- If all three are present, then they are combined to form a date. In all three modes, theYEAR
is validated. If the mode is smart or strict, then the month and day are validated. If the mode is lenient, then the date is combined in a manner equivalent to creating a date on the first day of the first month in the requested year, then adding the difference in months, then the difference in days. If the mode is smart, and the day-of-month is greater than the maximum for the year-month, then the day-of-month is adjusted to the last day-of-month. If the mode is strict, then the three fields must form a valid date. -
YEAR
andDAY_OF_YEAR
- If both are present, then they are combined to form a date. In all three modes, theYEAR
is validated. If the mode is lenient, then the date is combined in a manner equivalent to creating a date on the first day of the requested year, then adding the difference in days. If the mode is smart or strict, then the two fields must form a valid date. -
YEAR
,MONTH_OF_YEAR
,ALIGNED_WEEK_OF_MONTH
andALIGNED_DAY_OF_WEEK_IN_MONTH
- If all four are present, then they are combined to form a date. In all three modes, theYEAR
is validated. If the mode is lenient, then the date is combined in a manner equivalent to creating a date on the first day of the first month in the requested year, then adding the difference in months, then the difference in weeks, then in days. If the mode is smart or strict, then the all four fields are validated to their outer ranges. The date is then combined in a manner equivalent to creating a date on the first day of the requested year and month, then adding the amount in weeks and days to reach their values. If the mode is strict, the date is additionally validated to check that the day and week adjustment did not change the month. -
YEAR
,MONTH_OF_YEAR
,ALIGNED_WEEK_OF_MONTH
andDAY_OF_WEEK
- If all four are present, then they are combined to form a date. The approach is the same as described above for years, months and weeks inALIGNED_DAY_OF_WEEK_IN_MONTH
. The day-of-week is adjusted as the next or same matching day-of-week once the years, months and weeks have been handled. -
YEAR
,ALIGNED_WEEK_OF_YEAR
andALIGNED_DAY_OF_WEEK_IN_YEAR
- If all three are present, then they are combined to form a date. In all three modes, theYEAR
is validated. If the mode is lenient, then the date is combined in a manner equivalent to creating a date on the first day of the requested year, then adding the difference in weeks, then in days. If the mode is smart or strict, then the all three fields are validated to their outer ranges. The date is then combined in a manner equivalent to creating a date on the first day of the requested year, then adding the amount in weeks and days to reach their values. If the mode is strict, the date is additionally validated to check that the day and week adjustment did not change the year. -
YEAR
,ALIGNED_WEEK_OF_YEAR
andDAY_OF_WEEK
- If all three are present, then they are combined to form a date. The approach is the same as described above for years and weeks inALIGNED_DAY_OF_WEEK_IN_YEAR
. The day-of-week is adjusted as the next or same matching day-of-week once the years and weeks have been handled.
The default implementation is suitable for most calendar systems. If ChronoField.YEAR_OF_ERA
is found without an ChronoField.ERA
then the last era in Chronology.eras()
is used. The implementation assumes a 7 day week, that the first day-of-month has the value 1, that first day-of-year has the value 1, and that the first of the month and year always exists.
- Specified by:
-
resolveDate
in interfaceChronology
- Overrides:
-
resolveDate
in classAbstractChronology
- 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
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https://docs.oracle.com/javase/8/docs/api/java/time/chrono/JapaneseChronology.html