public final class JapaneseDate extends ChronoLocalDate implements java.io.Serializable
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.
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
JapaneseChEra.HEISEI.
| Modifier and Type | Method and Description |
|---|---|
ChronoLocalDateTime<JapaneseDate> |
atTime(LocalTime localTime)
Combines this date with a time to create a
ChronoLocalDateTime. |
boolean |
equals(java.lang.Object obj)
Checks if this date is equal to another date, including the chronology.
|
static JapaneseDate |
from(TemporalAccessor temporal)
Obtains a
JapaneseDate from a temporal object. |
JapaneseChronology |
getChronology()
Gets the chronology of this date.
|
JapaneseEra |
getEra()
Gets the era, as defined by the chronology.
|
long |
getLong(TemporalField field)
Gets the value of the specified field as a
long. |
int |
hashCode()
A hash code for this date.
|
boolean |
isSupported(TemporalField field)
Checks if the specified field is supported.
|
int |
lengthOfMonth()
Returns the length of the month represented by this date, as defined by the calendar system.
|
int |
lengthOfYear()
Returns the length of the year represented by this date, as defined by the calendar system.
|
JapaneseDate |
minus(long amountToAdd,
TemporalUnit unit)
Returns an object of the same type as this object with the specified period subtracted.
|
JapaneseDate |
minus(TemporalAmount amount)
Returns an object of the same type as this object with an amount subtracted.
|
static JapaneseDate |
now()
Obtains the current
JapaneseDate from the system clock in the default time-zone. |
static JapaneseDate |
now(Clock clock)
Obtains the current
JapaneseDate from the specified clock. |
static JapaneseDate |
now(ZoneId zone)
Obtains the current
JapaneseDate from the system clock in the specified time-zone. |
static JapaneseDate |
of(int prolepticYear,
int month,
int dayOfMonth)
Obtains a
JapaneseDate 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 a
JapaneseDate representing a date in the Japanese calendar
system from the era, year-of-era, month-of-year and day-of-month fields. |
JapaneseDate |
plus(long amountToAdd,
TemporalUnit unit)
Returns an object of the same type as this object with the specified period added.
|
JapaneseDate |
plus(TemporalAmount amount)
Returns an object of the same type as this object with an amount added.
|
ValueRange |
range(TemporalField field)
Gets the range of valid values for the specified field.
|
long |
toEpochDay()
Converts this date to the Epoch Day.
|
ChronoPeriod |
until(ChronoLocalDate endDate)
Calculates the period between this date and another date as a
ChronoPeriod. |
long |
until(Temporal endExclusive,
TemporalUnit unit)
Calculates the period between this temporal and another temporal in
terms of the specified unit.
|
JapaneseDate |
with(TemporalAdjuster adjuster)
Returns an adjusted object of the same type as this object with the adjustment made.
|
JapaneseDate |
with(TemporalField field,
long newValue)
Returns an object of the same type as this object with the specified field altered.
|
adjustInto, compareTo, format, isAfter, isBefore, isEqual, isLeapYear, isSupported, query, timeLineOrder, toStringgetclone, finalize, getClass, notify, notifyAll, wait, wait, waitisSupportedget, queryadjustIntopublic static JapaneseDate now()
JapaneseDate 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.
public static JapaneseDate now(ZoneId zone)
JapaneseDate 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.
zone - the zone ID to use, not nullpublic static JapaneseDate now(Clock clock)
JapaneseDate 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.
clock - the clock to use, not nullDateTimeException - if the current date cannot be obtainedpublic static JapaneseDate of(JapaneseEra era, int yearOfEra, int month, int dayOfMonth)
JapaneseDate 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
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 31DateTimeException - if the value of any field is out of range,
or if the day-of-month is invalid for the month-yearpublic static JapaneseDate of(int prolepticYear, int month, int dayOfMonth)
JapaneseDate 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.
prolepticYear - the Japanese proleptic-yearmonth - the Japanese month-of-year, from 1 to 12dayOfMonth - the Japanese day-of-month, from 1 to 31DateTimeException - if the value of any field is out of range,
or if the day-of-month is invalid for the month-yearpublic static JapaneseDate from(TemporalAccessor temporal)
JapaneseDate 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 of JapaneseDate.
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.
temporal - the temporal object to convert, not nullDateTimeException - if unable to convert to a JapaneseDatepublic JapaneseChronology getChronology()
ChronoLocalDate
The Chronology represents the calendar system in use.
The era and other fields in ChronoField are defined by the chronology.
getChronology in class ChronoLocalDatepublic JapaneseEra getEra()
ChronoLocalDate
The era is, conceptually, the largest division of the time-line.
Most calendar systems have a single epoch dividing the time-line into two eras.
However, some have multiple eras, such as one for the reign of each leader.
The exact meaning is determined by the Chronology.
All correctly implemented Era classes are singletons, thus it
is valid code to write date.getEra() == SomeEra.NAME).
getEra in class ChronoLocalDatepublic int lengthOfMonth()
ChronoLocalDateThis returns the length of the month in days.
lengthOfMonth in class ChronoLocalDatepublic int lengthOfYear()
ChronoLocalDateThis returns the length of the year in days.
The default implementation uses ChronoLocalDate.isLeapYear() and returns 365 or 366.
lengthOfYear in class ChronoLocalDatepublic boolean isSupported(TemporalField field)
This checks if this date can be queried for the specified field.
If false, then calling the range and
get 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 invoking TemporalField.isSupportedBy(TemporalAccessor)
passing this as the argument.
Whether the field is supported is determined by the field.
isSupported in interface TemporalAccessorisSupported in class ChronoLocalDatefield - the field to check, null returns falsepublic ValueRange range(TemporalField field)
TemporalAccessor
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.
ChronoField.
If the field is supported, then the range of the field must be returned.
If unsupported, then a DateTimeException must be thrown.
If the field is not a ChronoField, then the result of this method
is obtained by invoking TemporalField.rangeRefinedBy(TemporalAccessorl)
passing this as the argument.
Implementations must not alter either this object.
range in interface TemporalAccessorrange in class DefaultInterfaceTemporalAccessorfield - the field to query the range for, not nullpublic long getLong(TemporalField field)
TemporalAccessorlong.
This queries the date-time for the value for 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.
ChronoField.
If the field is supported, then the value of the field must be returned.
If unsupported, then a DateTimeException must be thrown.
If the field is not a ChronoField, then the result of this method
is obtained by invoking TemporalField.getFrom(TemporalAccessor)
passing this as the argument.
Implementations must not alter either this object.
getLong in interface TemporalAccessorfield - the field to get, not nullpublic JapaneseDate with(TemporalAdjuster adjuster)
Temporal
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 TemporalAdjusters date = date.with(next(WEDNESDAY)); // static import from TemporalAdjusters and DayOfWeek
with in interface Temporalwith in class ChronoLocalDateadjuster - the adjuster to use, not nullpublic JapaneseDate with(TemporalField field, long newValue)
Temporal
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.
ChronoField.
If the field is supported, then the adjustment must be performed.
If unsupported, then a DateTimeException must be thrown.
If the field is not a ChronoField, then the result of this method
is obtained by invoking TemporalField.adjustInto(Temporal, long)
passing this as the first argument.
Implementations must not alter either this object or the specified temporal object. Instead, an adjusted copy of the original must be returned. This provides equivalent, safe behavior for immutable and mutable implementations.
with in interface Temporalwith in class ChronoLocalDatefield - the field to set in the result, not nullnewValue - the new value of the field in the resultpublic JapaneseDate plus(TemporalAmount amount)
Temporal
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
the TemporalAdder interface, such as Duration.
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 by minus is not guaranteed to
return the same date-time.
plus in interface Temporalplus in class ChronoLocalDateamount - the amount to add, not nullpublic JapaneseDate plus(long amountToAdd, TemporalUnit unit)
Temporal
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.
If the implementation represents a date-time that has boundaries, such as LocalTime,
then the permitted units must include the boundary unit, but no multiples of the boundary unit.
For example, LocalTime must accept DAYS but not WEEKS or MONTHS.
ChronoUnit.
If the unit is supported, then the addition must be performed.
If unsupported, then a DateTimeException must be thrown.
If the unit is not a ChronoUnit, then the result of this method
is obtained by invoking TemporalUnit.addTo(Temporal, long)
passing this as the first argument.
Implementations must not alter either this object or the specified temporal object. Instead, an adjusted copy of the original must be returned. This provides equivalent, safe behavior for immutable and mutable implementations.
public JapaneseDate minus(TemporalAmount amount)
Temporal
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
the TemporalAmount interface, such as Duration.
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 by minus is not guaranteed to
return the same date-time.
minus in interface Temporalminus in class ChronoLocalDateamount - the amount to subtract, not nullpublic JapaneseDate minus(long amountToAdd, TemporalUnit unit)
Temporal
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.
If the implementation represents a date-time that has boundaries, such as LocalTime,
then the permitted units must include the boundary unit, but no multiples of the boundary unit.
For example, LocalTime must accept DAYS but not WEEKS or MONTHS.
Implementations must not alter either this object or the specified temporal object. Instead, an adjusted copy of the original must be returned. This provides equivalent, safe behavior for immutable and mutable implementations.
minus in interface Temporalminus in class ChronoLocalDateamountToAdd - the amount of the specified unit to subtract, may be negativeunit - the unit of the period to subtract, not nullpublic final ChronoLocalDateTime<JapaneseDate> atTime(LocalTime localTime)
ChronoLocalDateChronoLocalDateTime.
This returns a ChronoLocalDateTime formed from this date at the specified time.
All possible combinations of date and time are valid.
localTime - the local time to use, not nullpublic ChronoPeriod until(ChronoLocalDate endDate)
ChronoLocalDateChronoPeriod.
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.
endDate - the end date, exclusive, which may be in any chronology, not nullpublic long toEpochDay()
ChronoLocalDate
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.
toEpochDay in class ChronoLocalDatepublic boolean equals(java.lang.Object obj)
ChronoLocalDateCompares this date with another ensuring that the date and chronology are the same.
To compare the dates of two TemporalAccessor instances, including dates
in two different chronologies, use ChronoField.EPOCH_DAY as a comparator.
equals in class ChronoLocalDateobj - the object to check, null returns falsepublic int hashCode()
ChronoLocalDatehashCode in class ChronoLocalDatepublic long until(Temporal endExclusive, TemporalUnit unit)
Temporal
This calculates the period between two temporals in terms of a single unit.
The start and end points are this and the specified temporal.
The result will be negative if the end is before the start.
For example, the period in hours between two temporal objects can be
calculated using startTime.until(endTime, HOURS).
The calculation returns a whole number, representing the number of complete units between the two temporals. For example, the period in hours between the times 11:30 and 13:29 will only be one hour as it is one minute short of two hours.
There are two equivalent ways of using this method.
The first is to invoke this method directly.
The second is to use TemporalUnit.between(Temporal, Temporal):
// these two lines are equivalent between = thisUnit.between(start, end); between = start.until(end, thisUnit);The choice should be made based on which makes the code more readable.
For example, this method allows the number of days between two dates to be calculated:
long daysBetween = DAYS.between(start, end); // or alternatively long daysBetween = start.until(end, DAYS);
ChronoUnit.
A DateTimeException must be thrown for ChronoUnit
instances that are unsupported.
If the unit is not a ChronoUnit, then the result of this method
is obtained by invoking TemporalUnit.between(Temporal, Temporal)
passing this as the first argument and the input temporal as
the second argument.
In summary, implementations must behave in a manner equivalent to this code:
// check input temporal is the same type as this class
if (unit instanceof ChronoUnit) {
// if unit is supported, then calculate and return result
// else throw DateTimeException for unsupported units
}
return unit.between(this, endTemporal);
The target object must not be altered by this method.
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