JapaneseDate

atTime

fun atTime(localTime: LocalTime!): ChronoLocalDateTime<JapaneseDate!>!

Combines this date with a time to create a ChronoLocalDateTime.

This returns a ChronoLocalDateTime formed from this date at the specified time. All possible combinations of date and time are valid.

equals

fun equals(other: Any?): Boolean

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 two TemporalAccessor instances, including dates in two different chronologies, use ChronoField.EPOCH_DAY as a comparator.

from

static fun from(temporal: TemporalAccessor!): JapaneseDate!

Obtains a 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.

getChronology

fun getChronology(): JapaneseChronology!

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 in ChronoField are defined by the chronology.

getEra

fun getEra(): JapaneseEra!

Gets the era applicable at this date.

The Japanese calendar system has multiple eras defined by JapaneseEra.

getLong

fun getLong(field: TemporalField!): Long

Gets the value of the specified field as a long.

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.

hashCode

fun hashCode(): Int

A hash code for this date.

isSupported

fun isSupported(field: TemporalField!): Boolean

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 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

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.

lengthOfMonth

fun lengthOfMonth(): Int

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.

lengthOfYear

fun lengthOfYear(): Int

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 isLeapYear() and returns 365 or 366.

minus

fun minus(amount: TemporalAmount!): JapaneseDate!

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 java.time.Period but may be any other type implementing the TemporalAmount interface, such as java.time.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

fun minus(
    amountToAdd: Long, 
    unit: TemporalUnit!
): JapaneseDate!

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.

now

static fun now(): JapaneseDate!

Obtains the current 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.

now

static fun now(clock: Clock!): JapaneseDate!

Obtains the current 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.

now

static fun now(zone: ZoneId!): JapaneseDate!

Obtains the current 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.

of

static fun of(
    prolepticYear: Int, 
    month: Int, 
    dayOfMonth: Int
): JapaneseDate!

Obtains a 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.

of

static fun of(
    era: JapaneseEra!, 
    yearOfEra: Int, 
    month: Int, 
    dayOfMonth: Int
): JapaneseDate!

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.

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
  

plus

fun plus(amount: TemporalAmount!): JapaneseDate!

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 java.time.Period but may be any other type implementing the TemporalAmount interface, such as java.time.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

fun plus(
    amountToAdd: Long, 
    unit: TemporalUnit!
): JapaneseDate!

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.

range

fun range(field: TemporalField!): ValueRange!

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.

toEpochDay

fun toEpochDay(): Long

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.

toString

fun toString(): String

Returns a string representation of the object.

until

fun until(endDate: ChronoLocalDate!): ChronoPeriod!

Calculates the period between this date and another date as a ChronoPeriod.

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.

until

fun until(
    endExclusive: Temporal!, 
    unit: TemporalUnit!
): Long

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 single TemporalUnit. The start and end points are this and the specified date. The result will be negative if the end is before the start. The Temporal passed to this method is converted to a ChronoLocalDate using Chronology.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 using startDate.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 calculation is implemented in this method for ChronoUnit. The units DAYS, WEEKS, MONTHS, YEARS, DECADES, CENTURIES, MILLENNIA and ERAS should be supported by all implementations. Other ChronoUnit values will throw an exception.

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 converted input temporal as the second argument.

This instance is immutable and unaffected by this method call.

with

fun with(adjuster: TemporalAdjuster!): JapaneseDate!

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
  

with

fun with(
    field: TemporalField!, 
    newValue: Long
): JapaneseDate!

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.