- All Implemented Interfaces:
Serializable
,Comparable<ChronoLocalDate>
,ChronoLocalDate
,Temporal
,TemporalAccessor
,TemporalAdjuster
This date operates using the Japanese Imperial calendar. 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. The proleptic-year is defined to be equal to the ISO proleptic-year.
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.
For example, the Japanese year "Heisei 24" corresponds to ISO year "2012".
Calling japaneseDate.get(YEAR_OF_ERA)
will return 24.
Calling japaneseDate.get(YEAR)
will return 2012.
Calling japaneseDate.get(ERA)
will return 2, corresponding to
JapaneseChronology.ERA_HEISEI
.
This is a value-based
class; programmers should treat instances that are
equal as interchangeable and should not
use instances for synchronization, or unpredictable behavior may
occur. For example, in a future release, synchronization may fail.
The equals
method should be used for comparisons.
- Implementation Requirements:
- This class is immutable and thread-safe.
- Since:
- 1.8
- See Also:
-
Method Summary
Modifier and TypeMethodDescriptionfinal ChronoLocalDateTime<JapaneseDate>
Combines this date with a time to create aChronoLocalDateTime
.boolean
Compares this date to another date, including the chronology.static JapaneseDate
from
(TemporalAccessor temporal) Obtains aJapaneseDate
from a temporal object.Gets the chronology of this date, which is the Japanese calendar system.getEra()
Gets the era applicable at this date.long
getLong
(TemporalField field) Gets the value of the specified field as along
.int
hashCode()
A hash code for this date.boolean
isSupported
(TemporalField field) Checks if the specified field is supported.int
Returns the length of the month represented by this date.int
Returns the length of the year represented by this date, as defined by the calendar system.minus
(long amountToAdd, TemporalUnit unit) Returns an object of the same type as this object with the specified period subtracted.minus
(TemporalAmount amount) Returns an object of the same type as this object with an amount subtracted.static JapaneseDate
now()
Obtains the currentJapaneseDate
from the system clock in the default time-zone.static JapaneseDate
Obtains the currentJapaneseDate
from the specified clock.static JapaneseDate
Obtains the currentJapaneseDate
from the system clock in the specified time-zone.static JapaneseDate
of
(int prolepticYear, int month, int dayOfMonth) Obtains aJapaneseDate
representing a date in the Japanese calendar system from the proleptic-year, month-of-year and day-of-month fields.static JapaneseDate
of
(JapaneseEra era, int yearOfEra, int month, int dayOfMonth) Obtains aJapaneseDate
representing a date in the Japanese calendar system from the era, year-of-era, month-of-year and day-of-month fields.plus
(long amountToAdd, TemporalUnit unit) Returns an object of the same type as this object with the specified period added.plus
(TemporalAmount amount) Returns an object of the same type as this object with an amount added.range
(TemporalField field) Gets the range of valid values for the specified field.long
Converts this date to the Epoch Day.toString()
Returns a string representation of the object.until
(ChronoLocalDate endDate) Calculates the period between this date and another date as aChronoPeriod
.long
until
(Temporal endExclusive, TemporalUnit unit) Calculates the amount of time until another date in terms of the specified unit.with
(TemporalAdjuster adjuster) Returns an adjusted object of the same type as this object with the adjustment made.with
(TemporalField field, long newValue) Returns an object of the same type as this object with the specified field altered.Methods inherited from class java.lang.Object
clone, finalize, getClass, notify, notifyAll, wait, wait, wait
Methods inherited from interface java.time.chrono.ChronoLocalDate
adjustInto, compareTo, format, isAfter, isBefore, isEqual, isLeapYear, isSupported, query, toString, until
Methods inherited from interface java.time.temporal.TemporalAccessor
get
-
Method Details
-
now
Obtains the currentJapaneseDate
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.
- Returns:
- the current date using the system clock and default time-zone, not null
-
now
Obtains the currentJapaneseDate
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.
- Parameters:
zone
- the zone ID to use, not null- Returns:
- the current date using the system clock, not null
-
now
Obtains the currentJapaneseDate
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.
- Parameters:
clock
- the clock to use, not null- Returns:
- the current date, not null
- Throws:
DateTimeException
- if the current date cannot be obtained
-
of
Obtains aJapaneseDate
representing a date in the Japanese calendar system from the era, year-of-era, month-of-year and day-of-month fields.This returns a
JapaneseDate
with the specified fields. The day must be valid for the year and month, otherwise an exception will be thrown.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
- Parameters:
era
- the Japanese era, not nullyearOfEra
- the Japanese year-of-eramonth
- the Japanese month-of-year, from 1 to 12dayOfMonth
- the Japanese day-of-month, from 1 to 31- Returns:
- the date in Japanese calendar system, not null
- Throws:
DateTimeException
- if the value of any field is out of range, or if the day-of-month is invalid for the month-year, or if the date is not a Japanese era
-
of
Obtains aJapaneseDate
representing a date in the Japanese calendar system from the proleptic-year, month-of-year and day-of-month fields.This returns a
JapaneseDate
with the specified fields. The day must be valid for the year and month, otherwise an exception will be thrown.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.
- Parameters:
prolepticYear
- the Japanese proleptic-yearmonth
- the Japanese month-of-year, from 1 to 12dayOfMonth
- the Japanese day-of-month, from 1 to 31- Returns:
- the date in Japanese calendar system, not null
- Throws:
DateTimeException
- if the value of any field is out of range, or if the day-of-month is invalid for the month-year
-
from
Obtains aJapaneseDate
from a temporal object.This obtains a date in the Japanese calendar system based on the specified temporal. A
TemporalAccessor
represents an arbitrary set of date and time information, which this factory converts to an instance ofJapaneseDate
.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,JapaneseDate::from
.- Parameters:
temporal
- the temporal object to convert, not null- Returns:
- the date in Japanese calendar system, not null
- Throws:
DateTimeException
- if unable to convert to aJapaneseDate
- See Also:
-
getChronology
Gets the chronology of this date, which is the Japanese calendar system.The
Chronology
represents the calendar system in use. The era and other fields inChronoField
are defined by the chronology.- Specified by:
getChronology
in interfaceChronoLocalDate
- Returns:
- the Japanese chronology, not null
-
getEra
Gets the era applicable at this date.The Japanese calendar system has multiple eras defined by
JapaneseEra
.- Specified by:
getEra
in interfaceChronoLocalDate
- Returns:
- the era applicable at this date, not null
-
lengthOfMonth
public int lengthOfMonth()Returns the length of the month represented by this date.This returns the length of the month in days. Month lengths match those of the ISO calendar system.
- Specified by:
lengthOfMonth
in interfaceChronoLocalDate
- Returns:
- the length of the month in days
-
lengthOfYear
public int lengthOfYear()Description copied from interface:ChronoLocalDate
Returns the length of the year represented by this date, as defined by the calendar system.This returns the length of the year in days.
The default implementation uses
ChronoLocalDate.isLeapYear()
and returns 365 or 366.- Specified by:
lengthOfYear
in interfaceChronoLocalDate
- Returns:
- the length of the year in days
-
isSupported
Checks if the specified field is supported.This checks if this date can be queried for the specified field. If false, then calling the
range
andget
methods will throw an exception.If the field is a
ChronoField
then the query is implemented here. The supported fields are:DAY_OF_WEEK
DAY_OF_MONTH
DAY_OF_YEAR
EPOCH_DAY
MONTH_OF_YEAR
PROLEPTIC_MONTH
YEAR_OF_ERA
YEAR
ERA
ChronoField
instances will return false.If the field is not a
ChronoField
, then the result of this method is obtained by invokingTemporalField.isSupportedBy(TemporalAccessor)
passingthis
as the argument. Whether the field is supported is determined by the field.- Specified by:
isSupported
in interfaceChronoLocalDate
- Specified by:
isSupported
in interfaceTemporalAccessor
- Parameters:
field
- the field to check, null returns false- Returns:
- true if the field is supported on this date, false if not
-
range
Description copied from interface:TemporalAccessor
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. The value of this temporal object is used to enhance the accuracy of the returned range. If the date-time cannot return the range, because the field is unsupported or for some other reason, an exception will be thrown.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.
- Specified by:
range
in interfaceTemporalAccessor
- Parameters:
field
- the field to query the range for, not null- Returns:
- the range of valid values for the field, not null
-
getLong
Description copied from interface:TemporalAccessor
Gets the value of the specified field as along
.This queries the date-time for the value of the specified field. The returned value may be outside the valid range of values for the field. If the date-time cannot return the value, because the field is unsupported or for some other reason, an exception will be thrown.
- Specified by:
getLong
in interfaceTemporalAccessor
- Parameters:
field
- the field to get, not null- Returns:
- the value for the field
-
with
Description copied from interface:ChronoLocalDate
Returns an object of the same type as this object with the specified field altered.This returns a new object based on this one with the value for the specified field changed. For example, on a
LocalDate
, this could be used to set the year, month or day-of-month. The returned object will have the same observable type as this object.In some cases, changing a field is not fully defined. For example, if the target object is a date representing the 31st January, then changing the month to February would be unclear. In cases like this, the field is responsible for resolving the result. Typically it will choose the previous valid date, which would be the last valid day of February in this example.
- Specified by:
with
in interfaceChronoLocalDate
- Specified by:
with
in interfaceTemporal
- Parameters:
field
- the field to set in the result, not nullnewValue
- the new value of the field in the result- Returns:
- an object of the same type with the specified field set, not null
-
with
Returns an adjusted object of the same type as this object with the adjustment made.This adjusts this date-time according to the rules of the specified adjuster. A simple adjuster might simply set the one of the fields, such as the year field. A more complex adjuster might set the date to the last day of the month. A selection of common adjustments is provided in
TemporalAdjusters
. These include finding the "last day of the month" and "next Wednesday". The adjuster is responsible for handling special cases, such as the varying lengths of month and leap years.Some example code indicating how and why this method is used:
date = date.with(Month.JULY); // most key classes implement TemporalAdjuster date = date.with(lastDayOfMonth()); // static import from Adjusters date = date.with(next(WEDNESDAY)); // static import from Adjusters and DayOfWeek
- Specified by:
with
in interfaceChronoLocalDate
- Specified by:
with
in interfaceTemporal
- Parameters:
adjuster
- the adjuster to use, not null- Returns:
- an object of the same type with the specified adjustment made, not null
- Throws:
DateTimeException
- if unable to make the adjustmentArithmeticException
- if numeric overflow occurs
-
plus
Returns an object of the same type as this object with an amount added.This adjusts this temporal, adding according to the rules of the specified amount. The amount is typically a
Period
but may be any other type implementing theTemporalAmount
interface, such asDuration
.Some example code indicating how and why this method is used:
date = date.plus(period); // add a Period instance date = date.plus(duration); // add a Duration instance date = date.plus(workingDays(6)); // example user-written workingDays method
Note that calling
plus
followed byminus
is not guaranteed to return the same date-time.- Specified by:
plus
in interfaceChronoLocalDate
- Specified by:
plus
in interfaceTemporal
- Parameters:
amount
- the amount to add, not null- Returns:
- an object of the same type with the specified adjustment made, not null
- Throws:
DateTimeException
- if the addition cannot be madeArithmeticException
- if numeric overflow occurs
-
minus
Returns an object of the same type as this object with an amount subtracted.This adjusts this temporal, subtracting according to the rules of the specified amount. The amount is typically a
Period
but may be any other type implementing theTemporalAmount
interface, such asDuration
.Some example code indicating how and why this method is used:
date = date.minus(period); // subtract a Period instance date = date.minus(duration); // subtract a Duration instance date = date.minus(workingDays(6)); // example user-written workingDays method
Note that calling
plus
followed byminus
is not guaranteed to return the same date-time.- Specified by:
minus
in interfaceChronoLocalDate
- Specified by:
minus
in interfaceTemporal
- Parameters:
amount
- the amount to subtract, not null- Returns:
- an object of the same type with the specified adjustment made, not null
- Throws:
DateTimeException
- if the subtraction cannot be madeArithmeticException
- if numeric overflow occurs
-
plus
Description copied from interface:ChronoLocalDate
Returns an object of the same type as this object with the specified period added.This method returns a new object based on this one with the specified period added. For example, on a
LocalDate
, this could be used to add a number of years, months or days. The returned object will have the same observable type as this object.In some cases, changing a field is not fully defined. For example, if the target object is a date representing the 31st January, then adding one month would be unclear. In cases like this, the field is responsible for resolving the result. Typically it will choose the previous valid date, which would be the last valid day of February in this example.
- Specified by:
plus
in interfaceChronoLocalDate
- Specified by:
plus
in interfaceTemporal
- Parameters:
amountToAdd
- the amount of the specified unit to add, may be negativeunit
- the unit of the amount to add, not null- Returns:
- an object of the same type with the specified period added, not null
-
minus
Description copied from interface:ChronoLocalDate
Returns an object of the same type as this object with the specified period subtracted.This method returns a new object based on this one with the specified period subtracted. For example, on a
LocalDate
, this could be used to subtract a number of years, months or days. The returned object will have the same observable type as this object.In some cases, changing a field is not fully defined. For example, if the target object is a date representing the 31st March, then subtracting one month would be unclear. In cases like this, the field is responsible for resolving the result. Typically it will choose the previous valid date, which would be the last valid day of February in this example.
- Specified by:
minus
in interfaceChronoLocalDate
- Specified by:
minus
in interfaceTemporal
- Parameters:
amountToAdd
- the amount of the specified unit to subtract, may be negativeunit
- the unit of the amount to subtract, not null- Returns:
- an object of the same type with the specified period subtracted, not null
-
atTime
Description copied from interface:ChronoLocalDate
Combines this date with a time to create aChronoLocalDateTime
.This returns a
ChronoLocalDateTime
formed from this date at the specified time. All possible combinations of date and time are valid.- Specified by:
atTime
in interfaceChronoLocalDate
- Parameters:
localTime
- the local time to use, not null- Returns:
- the local date-time formed from this date and the specified time, not null
-
until
Description copied from interface:ChronoLocalDate
Calculates the period between this date and another date as aChronoPeriod
.This calculates the period between two dates. All supplied chronologies calculate the period using years, months and days, however the
ChronoPeriod
API allows the period to be represented using other units.The start and end points are
this
and the specified date. The result will be negative if the end is before the start. The negative sign will be the same in each of year, month and day.The calculation is performed using the chronology of this date. If necessary, the input date will be converted to match.
This instance is immutable and unaffected by this method call.
- Specified by:
until
in interfaceChronoLocalDate
- Parameters:
endDate
- the end date, exclusive, which may be in any chronology, not null- Returns:
- the period between this date and the end date, not null
-
toEpochDay
public long toEpochDay()Description copied from interface:ChronoLocalDate
Converts this date to the Epoch Day.The
Epoch Day count
is a simple incrementing count of days where day 0 is 1970-01-01 (ISO). This definition is the same for all chronologies, enabling conversion.This default implementation queries the
EPOCH_DAY
field.- Specified by:
toEpochDay
in interfaceChronoLocalDate
- Returns:
- the Epoch Day equivalent to this date
-
equals
Compares this date to another date, including the chronology.Compares this
JapaneseDate
with another ensuring that the date is the same.Only objects of type
JapaneseDate
are compared, other types return false. To compare the dates of twoTemporalAccessor
instances, including dates in two different chronologies, useChronoField.EPOCH_DAY
as a comparator.- Specified by:
equals
in interfaceChronoLocalDate
- Parameters:
obj
- the object to check, null returns false- Returns:
- true if this is equal to the other date
- See Also:
-
hashCode
public int hashCode()A hash code for this date.- Specified by:
hashCode
in interfaceChronoLocalDate
- Returns:
- a suitable hash code based only on the Chronology and the date
- See Also:
-
until
Description copied from interface:ChronoLocalDate
Calculates the amount of time until another date in terms of the specified unit.This calculates the amount of time between two
ChronoLocalDate
objects in terms of a singleTemporalUnit
. The start and end points arethis
and the specified date. The result will be negative if the end is before the start. TheTemporal
passed to this method is converted to aChronoLocalDate
usingChronology.date(TemporalAccessor)
. The calculation returns a whole number, representing the number of complete units between the two dates. For example, the amount in days between two dates can be calculated usingstartDate.until(endDate, DAYS)
.There are two equivalent ways of using this method. The first is to invoke this method. The second is to use
TemporalUnit.between(Temporal, Temporal)
:// these two lines are equivalent amount = start.until(end, MONTHS); amount = MONTHS.between(start, end);
The choice should be made based on which makes the code more readable.The calculation is implemented in this method for
ChronoUnit
. The unitsDAYS
,WEEKS
,MONTHS
,YEARS
,DECADES
,CENTURIES
,MILLENNIA
andERAS
should be supported by all implementations. OtherChronoUnit
values will throw an exception.If the unit is not a
ChronoUnit
, then the result of this method is obtained by invokingTemporalUnit.between(Temporal, Temporal)
passingthis
as the first argument and the converted input temporal as the second argument.This instance is immutable and unaffected by this method call.
- Specified by:
until
in interfaceChronoLocalDate
- Specified by:
until
in interfaceTemporal
- Parameters:
endExclusive
- the end date, exclusive, which is converted to aChronoLocalDate
in the same chronology, not nullunit
- the unit to measure the amount in, not null- Returns:
- the amount of time between this date and the end date
-
toString
Description copied from class:Object
Returns a string representation of the object.- Specified by:
toString
in interfaceChronoLocalDate
- Overrides:
toString
in classObject
- Returns:
- a string representation of the object.
-