Class JapaneseEra

java.lang.Object

java.time.chrono.JapaneseEra

All Implemented Interfaces:: Serializable, Era, TemporalAccessor, TemporalAdjuster

public final class JapaneseEra extends Object implements Era, Serializable

An era in the Japanese Imperial calendar system.

The Japanese government defines the official name and start date of each era. Eras are consecutive and their date ranges do not overlap, so the end date of one era is always the day before the start date of the next era.

The Java SE Platform supports all eras defined by the Japanese government, beginning with the Meiji era. Each era is identified in the Platform by an integer value and a name. The of(int) and valueOf(String) methods may be used to obtain a singleton instance of JapaneseEra for each era. The values() method returns the singleton instances of all supported eras.

For convenience, this class declares a number of public static final fields that refer to singleton instances returned by the values() method.

API Note:

The fields declared in this class may evolve over time, in line with the results of the values() method. However, there is not necessarily a 1:1 correspondence between the fields and the singleton instances., The Japanese government may announce a new era and define its start date but not its official name. In this scenario, the singleton instance that represents the new era may return a name that is not stable until the official name is defined. Developers should exercise caution when relying on the name returned by any singleton instance that does not correspond to a public static final field.

Implementation Requirements:

This class is immutable and thread-safe.

Since:

1.8

See Also:

Field Summary

Modifier and Type	Field	Description
`static final JapaneseEra`	`HEISEI`	The singleton instance for the 'Heisei' era (1989-01-08 - 2019-04-30) which has the value 2.
`static final JapaneseEra`	`MEIJI`	The singleton instance for the 'Meiji' era (1868-01-01 - 1912-07-29) which has the value -1.
`static final JapaneseEra`	`REIWA`	The singleton instance for the 'Reiwa' era (2019-05-01 - ) which has the value 3.
`static final JapaneseEra`	`SHOWA`	The singleton instance for the 'Showa' era (1926-12-25 - 1989-01-07) which has the value 1.
`static final JapaneseEra`	`TAISHO`	The singleton instance for the 'Taisho' era (1912-07-30 - 1926-12-24) which has the value 0.

Method Summary

Modifier and Type	Method	Description
`String`	`getDisplayName(TextStyle style, Locale locale)`	Gets the textual representation of this era.
`int`	`getValue()`	Gets the numeric era `int` value.
`static JapaneseEra`	`of(int japaneseEra)`	Obtains an instance of `JapaneseEra` from an `int` value.
`ValueRange`	`range(TemporalField field)`	Gets the range of valid values for the specified field.
`static JapaneseEra`	`valueOf(String japaneseEra)`	Returns the `JapaneseEra` with the name.
`static JapaneseEra[]`	`values()`	Returns an array of JapaneseEras.

Methods declared in class Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Modifier and Type	Method	Description
`protected Object`	`clone()`	Creates and returns a copy of this object.
`boolean`	`equals(Object obj)`	Indicates whether some other object is "equal to" this one.
`protected void`	`finalize()`	Deprecated, for removal: This API element is subject to removal in a future version. Finalization is deprecated and subject to removal in a future release.
`final Class<?>`	`getClass()`	Returns the runtime class of this `Object`.
`int`	`hashCode()`	Returns a hash code value for this object.
`final void`	`notify()`	Wakes up a single thread that is waiting on this object's monitor.
`final void`	`notifyAll()`	Wakes up all threads that are waiting on this object's monitor.
`String`	`toString()`	Returns a string representation of the object.
`final void`	`wait()`	Causes the current thread to wait until it is awakened, typically by being notified or interrupted.
`final void`	`wait(long timeoutMillis)`	Causes the current thread to wait until it is awakened, typically by being notified or interrupted, or until a certain amount of real time has elapsed.
`final void`	`wait(long timeoutMillis, int nanos)`	Causes the current thread to wait until it is awakened, typically by being notified or interrupted, or until a certain amount of real time has elapsed.

Methods declared in interface Era

adjustInto, get, getLong, isSupported, query

Modifier and Type	Method	Description
`default Temporal`	`adjustInto(Temporal temporal)`	Adjusts the specified temporal object to have the same era as this object.
`default int`	`get(TemporalField field)`	Gets the value of the specified field from this era as an `int`.
`default long`	`getLong(TemporalField field)`	Gets the value of the specified field from this era as a `long`.
`default boolean`	`isSupported(TemporalField field)`	Checks if the specified field is supported.
`default <R> R`	`query(TemporalQuery<R> query)`	Queries this era using the specified query.

Field Details

MEIJI

public static final JapaneseEra MEIJI

The singleton instance for the 'Meiji' era (1868-01-01 - 1912-07-29) which has the value -1.

TAISHO

public static final JapaneseEra TAISHO

The singleton instance for the 'Taisho' era (1912-07-30 - 1926-12-24) which has the value 0.

SHOWA

public static final JapaneseEra SHOWA

The singleton instance for the 'Showa' era (1926-12-25 - 1989-01-07) which has the value 1.

HEISEI

public static final JapaneseEra HEISEI

The singleton instance for the 'Heisei' era (1989-01-08 - 2019-04-30) which has the value 2.

REIWA

public static final JapaneseEra REIWA

The singleton instance for the 'Reiwa' era (2019-05-01 - ) which has the value 3. The end date of this era is not specified, unless the Japanese Government defines it.

Since:: 13

Method Details

of

public static JapaneseEra of(int japaneseEra)

Obtains an instance of JapaneseEra from an int value.

The value 1 is associated with the 'Showa' era, because it contains 1970-01-01 (ISO calendar system).
The values -1 and 0 are associated with two earlier eras, Meiji and Taisho, respectively.
A value greater than 1 is associated with a later era, beginning with Heisei (2).

Every instance of JapaneseEra that is returned from the values() method has an int value (available via Era.getValue() which is accepted by this method.

Parameters:: japaneseEra - the era to represent
Returns:: the JapaneseEra singleton, not null
Throws:: DateTimeException - if the value is invalid

valueOf

public static JapaneseEra valueOf(String japaneseEra)

Returns the JapaneseEra with the name.

The string must match exactly the name of the era. (Extraneous whitespace characters are not permitted.)

Valid era names are the names of eras returned from values().

Parameters:: japaneseEra - the japaneseEra name; non-null
Returns:: the JapaneseEra singleton, never null
Throws:: IllegalArgumentException - if there is not JapaneseEra with the specified name

values

public static JapaneseEra[] values()

Returns an array of JapaneseEras. The array may contain eras defined by the Japanese government beyond the known era singletons.

This method may be used to iterate over the JapaneseEras as follows:

for (JapaneseEra c : JapaneseEra.values())
    System.out.println(c);

Returns:: an array of JapaneseEras

getDisplayName

public String getDisplayName(TextStyle style, Locale locale)

Gets the textual representation of this era.

This returns the textual name used to identify the era, suitable for presentation to the user. The parameters control the style of the returned text and the locale.

If no textual mapping is found then the numeric value is returned.

Specified by:: getDisplayName in interface Era
Parameters:: style - the style of the text required, not null; locale - the locale to use, not null
Returns:: the text value of the era, not null

getValue

public int getValue()

Gets the numeric era int value.

The SHOWA era that contains 1970-01-01 (ISO calendar system) has the value 1. Later eras are numbered from 2 (HEISEI). Earlier eras are numbered 0 (TAISHO), -1 (MEIJI)).

Specified by:: getValue in interface Era
Returns:: the era value

range

public ValueRange range(TemporalField field)

Gets the range of valid values for the specified field.

The range object expresses the minimum and maximum valid values for a field. This era is used to enhance the accuracy of the returned range. If it is not possible to return the range, because the field is not supported or for some other reason, an exception is thrown.

If the field is a ChronoField then the query is implemented here. The ERA field returns the range. All other ChronoField instances will throw an UnsupportedTemporalTypeException.

If the field is not a ChronoField, then the result of this method is obtained by invoking TemporalField.rangeRefinedBy(TemporalAccessor) passing this as the argument. Whether the range can be obtained is determined by the field.

The range of valid Japanese eras can change over time due to the nature of the Japanese calendar system.

Specified by:: range in interface Era
Specified by:: range in interface TemporalAccessor
Parameters:: field - the field to query the range for, not null
Returns:: the range of valid values for the field, not null
Throws:: DateTimeException - if the range for the field cannot be obtained; UnsupportedTemporalTypeException - if the unit is not supported

© 1993, 2025, Oracle and/or its affiliates. All rights reserved.
Documentation extracted from Debian's OpenJDK Development Kit package.
Licensed under the GNU General Public License, version 2, with the Classpath Exception.
Various third party code in OpenJDK is licensed under different licenses (see Debian package).
Java and OpenJDK are trademarks or registered trademarks of Oracle and/or its affiliates.