Java Module java.base Package java.time.chrono Class JapaneseDate（JDK11）

Method Detail

• now

  public static JapaneseDate now()

  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.

  Returns:

  the current date using the system clock and default time-zone, not null

• now

  public static JapaneseDate now​(ZoneId zone)

  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.

  Parameters:

  zone - the zone ID to use, not null

  Returns:

  the current date using the system clock, not null

• now

  public static JapaneseDate now​(Clock clock)

  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.

  Parameters:

  clock - the clock to use, not null

  Returns:

  the current date, not null

  Throws:

  DateTimeException - if the current date cannot be obtained

• of

  public 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.

  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 null

  yearOfEra - the Japanese year-of-era

  month - the Japanese month-of-year, from 1 to 12

  dayOfMonth - 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

  public 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.

  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-year

  month - the Japanese month-of-year, from 1 to 12

  dayOfMonth - 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

  public static JapaneseDate from​(TemporalAccessor temporal)

  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.

  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 a JapaneseDate

  See Also:

  Chronology.date(TemporalAccessor)

• getChronology

  public JapaneseChronology 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 in ChronoField are defined by the chronology.

  Specified by:

  getChronology in interface ChronoLocalDate

  Returns:

  the Japanese chronology, not null

• getEra

  public JapaneseEra getEra()

  Gets the era applicable at this date.

  The Japanese calendar system has multiple eras defined by JapaneseEra.

  Specified by:

  getEra in interface ChronoLocalDate

  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 interface ChronoLocalDate

  Returns:

  the length of the month in days

• isSupported

  public boolean isSupported​(TemporalField field)

  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

  All other 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.

  Specified by:

  isSupported in interface ChronoLocalDate

  Specified by:

  isSupported in interface TemporalAccessor

  Parameters:

  field - the field to check, null returns false

  Returns:

  true if the field is supported on this date, false if not

• with

  public JapaneseDate with​(TemporalAdjuster adjuster)

  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 interface ChronoLocalDate

  Specified by:

  with in interface Temporal

  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 adjustment

  ArithmeticException - if numeric overflow occurs

• plus

  public JapaneseDate plus​(TemporalAmount amount)

  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 the TemporalAmount 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.

  Specified by:

  plus in interface ChronoLocalDate

  Specified by:

  plus in interface Temporal

  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 made

  ArithmeticException - if numeric overflow occurs

• minus

  public JapaneseDate minus​(TemporalAmount amount)

  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 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.

  Specified by:

  minus in interface ChronoLocalDate

  Specified by:

  minus in interface Temporal

  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 made

  ArithmeticException - if numeric overflow occurs

• equals

  public boolean equals​(Object obj)

  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.

  Specified by:

  equals in interface ChronoLocalDate

  Parameters:

  obj - the object to check, null returns false

  Returns:

  true if this is equal to the other date

  See Also:

  Object.hashCode(), HashMap

• hashCode

  public int hashCode()

  A hash code for this date.

  Specified by:

  hashCode in interface ChronoLocalDate

  Returns:

  a suitable hash code based only on the Chronology and the date

  See Also:

  Object.equals(java.lang.Object), System.identityHashCode(java.lang.Object)

• until

  public long until​(Temporal endExclusive,
                    TemporalUnit unit)

  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 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 choice should be made based on which makes the code more readable.

  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.

  Specified by:

  until in interface ChronoLocalDate

  Specified by:

  until in interface Temporal

  Parameters:

  endExclusive - the end date, exclusive, which is converted to a ChronoLocalDate in the same chronology, not null

  unit - the unit to measure the amount in, not null

  Returns:

  the amount of time between this date and the end date

• toString

  public String toString()

  Description copied from class: Object
  Returns a string representation of the object. In general, the toString method returns a string that "textually represents" this object. The result should be a concise but informative representation that is easy for a person to read. It is recommended that all subclasses override this method.

  The toString method for class Object returns a string consisting of the name of the class of which the object is an instance, the at-sign character `@', and the unsigned hexadecimal representation of the hash code of the object. In other words, this method returns a string equal to the value of:

   getClass().getName() + '@' + Integer.toHexString(hashCode())
   

  Specified by:

  toString in interface ChronoLocalDate

  Overrides:

  toString in class Object

  Returns:

  a string representation of the object.