Java : JapaneseDate with Examples

final var date = JapaneseDate.of(2000, 4, 15);
System.out.println(date); // Japanese Heisei 12-04-15

final var era = date.getEra();
final var name = era.getDisplayName(TextStyle.FULL, Locale.JAPAN);
System.out.println(name); // 平成

final var isoDate = LocalDate.from(date);
System.out.println(isoDate); // 2000-04-15

final var date = JapaneseDate.of(JapaneseEra.REIWA, 1, 5, 10);
System.out.println(date); // Japanese Reiwa 1-05-10

final var era = date.getEra();
final var name = era.getDisplayName(TextStyle.FULL, Locale.JAPAN);
System.out.println(name); // 令和

final var isoDate = LocalDate.from(date);
System.out.println(isoDate); // 2019-05-10

final ChronoLocalDateTime<JapaneseDate> atTime (LocalTime localTime)

Combines this date with a time to create a ChronoLocalDateTime.

final var date = JapaneseDate.of(2000, 4, 15);
System.out.println(date); // Japanese Heisei 12-04-15

{
    final var time = LocalTime.of(12, 30);
    System.out.println(time); // 12:30
    System.out.println(date.atTime(time)); // Japanese Heisei 12-04-15T12:30
}
{
    final var time = LocalTime.of(12, 30, 45);
    System.out.println(time); // 12:30:45
    System.out.println(date.atTime(time)); // Japanese Heisei 12-04-15T12:30:45
}
{
    final var time = LocalTime.of(12, 30, 45, 123456789);
    System.out.println(time); // 12:30:45.123456789
    System.out.println(date.atTime(time)); // Japanese Heisei 12-04-15T12:30:45.123456789
}

boolean equals (Object obj)

Compares this date to another date, including the chronology.

final var date1 = JapaneseDate.of(2000, 4, 15);
final var date2 = JapaneseDate.of(2000, 4, 15);

System.out.println(date1); // Japanese Heisei 12-04-15
System.out.println(date2); // Japanese Heisei 12-04-15

System.out.println(date1.equals(date2)); // true

final var date1 = JapaneseDate.of(1989, 10, 15);
final var date2 = JapaneseDate.of(2019, 10, 15);
final var date3 = JapaneseDate.of(2020, 3, 1);

System.out.println(date1); // Japanese Heisei 1-10-15
System.out.println(date2); // Japanese Reiwa 1-10-15
System.out.println(date3); // Japanese Reiwa 2-03-01

System.out.println(date1.equals(date2)); // false
System.out.println(date1.equals(date3)); // false
System.out.println(date2.equals(date3)); // false

static JapaneseDate from (TemporalAccessor temporal)

Obtains a JapaneseDate from a temporal object.

final var temporal = LocalDate.of(2000, 4, 15);
System.out.println(temporal); // 2000-04-15
System.out.println(JapaneseDate.from(temporal)); // Japanese Heisei 12-04-15

final var temporal = LocalDateTime.of(2019, 5, 10, 16, 30);
System.out.println(temporal); // 2019-05-10T16:30
System.out.println(JapaneseDate.from(temporal)); // Japanese Reiwa 1-05-10

JapaneseChronology getChronology ()

Gets the chronology of this date, which is the Japanese calendar system.

final var date = JapaneseDate.of(2000, 4, 15);
System.out.println(date); // Japanese Heisei 12-04-15
System.out.println(date.getChronology()); // Japanese
System.out.println(date.getEra()); // Heisei

JapaneseEra getEra ()

Gets the era applicable at this date.

final var date = JapaneseDate.of(2000, 4, 15);
System.out.println(date); // Japanese Heisei 12-04-15
System.out.println(date.getChronology()); // Japanese
System.out.println(date.getEra()); // Heisei

long getLong (TemporalField field)

Gets the value of the specified field as a long.

final var date = JapaneseDate.of(2000, 4, 15);
System.out.println(date); // Japanese Heisei 12-04-15

final var year = date.getLong(ChronoField.YEAR);
System.out.println(year); // 2000

final var yearOfEra = date.getLong(ChronoField.YEAR_OF_ERA);
System.out.println(yearOfEra); // 12

final var month = date.getLong(ChronoField.MONTH_OF_YEAR);
System.out.println(month); // 4

final var day = date.getLong(ChronoField.DAY_OF_MONTH);
System.out.println(day); // 15

int hashCode ()

A hash code for this date.

final var date1 = JapaneseDate.of(1970, 1, 1);
System.out.println(date1.hashCode()); // -691981424

final var date2 = JapaneseDate.of(1970, 1, 2);
System.out.println(date2.hashCode()); // -691981421

final var date3 = JapaneseDate.of(2019, 5, 1);
System.out.println(date3.hashCode()); // -691815792

boolean isSupported (TemporalField field)

Checks if the specified field is supported.

final var date = JapaneseDate.of(2000, 4, 15);
System.out.println(date); // Japanese Heisei 12-04-15

System.out.println("-- supported fields --");
for (final var field : ChronoField.values()) {
    if (date.isSupported(field)) {
        System.out.println(field);
    }
}

// Result
// ↓
//-- supported fields --
//DayOfWeek
//DayOfMonth
//DayOfYear
//EpochDay
//MonthOfYear
//ProlepticMonth
//YearOfEra
//Year
//Era

int lengthOfMonth ()

Returns the length of the month represented by this date.

final var date = JapaneseDate.of(2019, 1, 1);
System.out.println(date); // Japanese Heisei 31-01-01

System.out.println(date.lengthOfMonth()); // 31

final var date = JapaneseDate.of(2019, 2, 1);
System.out.println(date); // Japanese Heisei 31-02-01

System.out.println(date.isLeapYear()); // false
System.out.println(date.lengthOfMonth()); // 28

final var date = JapaneseDate.of(2020, 2, 1);
System.out.println(date); // Japanese Reiwa 2-02-01

System.out.println(date.isLeapYear()); // true
System.out.println(date.lengthOfMonth()); // 29

JapaneseDate minus (long amountToSubtract, TemporalUnit unit)

Returns an object of the same type as this object with the specified period subtracted.

final var date = JapaneseDate.of(1998, 5, 20);
System.out.println(date); // Japanese Heisei 10-05-20

System.out.println(date.minus(1, ChronoUnit.DAYS)); // Japanese Heisei 10-05-19
System.out.println(date.minus(2, ChronoUnit.MONTHS)); // Japanese Heisei 10-03-20
System.out.println(date.minus(3, ChronoUnit.YEARS)); // Japanese Heisei 7-05-20

JapaneseDate minus (TemporalAmount amount)

Returns an object of the same type as this object with an amount subtracted.

final var date1 = JapaneseDate.of(1998, 5, 20);
System.out.println(date1); // Japanese Heisei 10-05-20

final var date2 = JapaneseDate.of(1998, 5, 22);
System.out.println(date2); // Japanese Heisei 10-05-22

final var amount = date1.until(date2);
System.out.println(amount); // Japanese P2D

System.out.println(date1.minus(amount)); // Japanese Heisei 10-05-18
System.out.println(date2.minus(amount)); // Japanese Heisei 10-05-20

static JapaneseDate now ()

Obtains the current JapaneseDate from the system clock in the default time-zone.

final var now = JapaneseDate.now();
System.out.println(now); // Japanese Reiwa 6-07-18

static JapaneseDate now (Clock clock)

Obtains the current JapaneseDate from the specified clock.

// A clock advanced 5 days.
final var clock = Clock.offset(Clock.systemDefaultZone(), Duration.ofDays(5));

final var now1 = JapaneseDate.now();
System.out.println(now1); // Japanese Reiwa 6-07-18

final var now2 = JapaneseDate.now(clock);
System.out.println(now2); // Japanese Reiwa 6-07-23

static JapaneseDate now (ZoneId zone)

Obtains the current JapaneseDate from the system clock in the specified time-zone.

final var zone = ZoneId.of("JST", ZoneId.SHORT_IDS);
System.out.println(zone); // Asia/Tokyo

final var now = JapaneseDate.now(zone);
System.out.println(now); // Japanese Reiwa 6-07-18

final var zone = ZoneId.of("PST", ZoneId.SHORT_IDS);
System.out.println(zone); // America/Los_Angeles

final var now = JapaneseDate.now(zone);
System.out.println(now); // Japanese Reiwa 6-07-17

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.

final var date = JapaneseDate.of(2000, 4, 15);
System.out.println(date); // Japanese Heisei 12-04-15

final var isoDate = LocalDate.from(date);
System.out.println(isoDate); // 2000-04-15

final var date = JapaneseDate.of(JapaneseEra.REIWA, 1, 5, 10);
System.out.println(date); // Japanese Reiwa 1-05-10

final var isoDate = LocalDate.from(date);
System.out.println(isoDate); // 2019-05-10

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.

final var date = JapaneseDate.of(2000, 4, 15);
System.out.println(date); // Japanese Heisei 12-04-15

final var isoDate = LocalDate.from(date);
System.out.println(isoDate); // 2000-04-15

final var date = JapaneseDate.of(JapaneseEra.REIWA, 1, 5, 10);
System.out.println(date); // Japanese Reiwa 1-05-10

final var isoDate = LocalDate.from(date);
System.out.println(isoDate); // 2019-05-10

JapaneseDate plus (long amountToAdd, TemporalUnit unit)

Returns an object of the same type as this object with the specified period added.

final var date = JapaneseDate.of(1998, 5, 20);
System.out.println(date); // Japanese Heisei 10-05-20

System.out.println(date.plus(1, ChronoUnit.DAYS)); // Japanese Heisei 10-05-21
System.out.println(date.plus(2, ChronoUnit.MONTHS)); // Japanese Heisei 10-07-20
System.out.println(date.plus(3, ChronoUnit.YEARS)); // Japanese Heisei 13-05-20

JapaneseDate plus (TemporalAmount amount)

Returns an object of the same type as this object with an amount added.

final var date1 = JapaneseDate.of(1998, 5, 20);
System.out.println(date1); // Japanese Heisei 10-05-20

final var date2 = JapaneseDate.of(1998, 5, 22);
System.out.println(date2); // Japanese Heisei 10-05-22

final var amount = date1.until(date2);
System.out.println(amount); // Japanese P2D

System.out.println(date1.plus(amount)); // Japanese Heisei 10-05-22
System.out.println(date2.plus(amount)); // Japanese Heisei 10-05-24

String toString ()

Returns a string representation of the object.

final var date = JapaneseDate.of(2000, 4, 15);
final var str = date.toString();
System.out.println(str); // Japanese Heisei 12-04-15

final var date = JapaneseDate.of(JapaneseEra.REIWA, 1, 5, 10);
final var str = date.toString();
System.out.println(str); // Japanese Reiwa 1-05-10

ChronoPeriod until (ChronoLocalDate endDate)

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

final var date1 = JapaneseDate.of(2000, 1, 15);
final var date2 = JapaneseDate.of(2001, 3, 18);

System.out.println(date1); // Japanese Heisei 12-01-15
System.out.println(date2); // Japanese Heisei 13-03-18

final var period1 = date1.until(date2);
System.out.println(period1.get(ChronoUnit.YEARS)); // 1
System.out.println(period1.get(ChronoUnit.MONTHS)); // 2
System.out.println(period1.get(ChronoUnit.DAYS)); // 3

final var period2 = date2.until(date1);
System.out.println(period2.get(ChronoUnit.YEARS)); // -1
System.out.println(period2.get(ChronoUnit.MONTHS)); // -2
System.out.println(period2.get(ChronoUnit.DAYS)); // -3

long until (Temporal endExclusive, TemporalUnit unit)

Calculates the amount of time until another date in terms of the specified unit.

final var date1 = JapaneseDate.of(2000, 1, 15);
final var date2 = JapaneseDate.of(2001, 3, 18);

System.out.println(date1); // Japanese Heisei 12-01-15
System.out.println(date2); // Japanese Heisei 13-03-18

System.out.println(date1.until(date2, ChronoUnit.YEARS)); // 1
System.out.println(date1.until(date2, ChronoUnit.MONTHS)); // 14
System.out.println(date1.until(date2, ChronoUnit.DAYS)); // 427

JapaneseDate with (TemporalAdjuster adjuster)

Returns an adjusted object of the same type as this object with the adjustment made.

final var date = JapaneseDate.of(2000, 4, 15);
System.out.println(date); // Japanese Heisei 12-04-15

final var ret1 = date.with(TemporalAdjusters.firstDayOfMonth());
System.out.println(ret1); // Japanese Heisei 12-04-01

final var ret2 = date.with(TemporalAdjusters.lastDayOfMonth());
System.out.println(ret2); // Japanese Heisei 12-04-30

JapaneseDate with (TemporalField field, long newValue)

Returns an object of the same type as this object with the specified field altered.

final var date = JapaneseDate.of(1998, 4, 15);
System.out.println(date); // Japanese Heisei 10-04-15

final var ret1 = date.with(ChronoField.YEAR_OF_ERA, 20);
System.out.println(ret1); // Japanese Heisei 20-04-15

final var ret2 = date.with(ChronoField.MONTH_OF_YEAR, 12);
System.out.println(ret2); // Japanese Heisei 10-12-15

final var ret3 = date.with(ChronoField.DAY_OF_MONTH, 30);
System.out.println(ret3); // Japanese Heisei 10-04-30

adjustInto, compareTo, format, isAfter, isBefore, isEqual, isLeapYear, isSupported, lengthOfYear, query, toEpochDay, toString, until

Please see the link below.

• ChronoLocalDate with Examples

get, range

Please see the link below.

• TemporalAccessor with Examples