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
methods may be used to obtain a singleton instance of
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
- 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.
- See Also:
- Serialized Form
Field SummaryModifier and TypeFieldDescriptionThe singleton instance for the 'Heisei' era (1989-01-08 - 2019-04-30) which has the value 2.The singleton instance for the 'Meiji' era (1868-01-01 - 1912-07-29) which has the value -1.The singleton instance for the 'Reiwa' era (2019-05-01 - ) which has the value 3.The singleton instance for the 'Showa' era (1926-12-25 - 1989-01-07) which has the value 1.The singleton instance for the 'Taisho' era (1912-07-30 - 1926-12-24) which has the value 0.
Method SummaryModifier and TypeMethodDescriptionGets the textual representation of this era.
getValue()Gets the numeric era
of(int japaneseEra)Obtains an instance of
intvalue.Gets the range of valid values for the specified field.
static JapaneseEraReturns the
JapaneseErawith the name.
values()Returns an array of JapaneseEras.
Methods declared in class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
MEIJIpublic static final JapaneseEra MEIJIThe singleton instance for the 'Meiji' era (1868-01-01 - 1912-07-29) which has the value -1.
TAISHOpublic static final JapaneseEra TAISHOThe singleton instance for the 'Taisho' era (1912-07-30 - 1926-12-24) which has the value 0.
SHOWApublic static final JapaneseEra SHOWAThe singleton instance for the 'Showa' era (1926-12-25 - 1989-01-07) which has the value 1.
HEISEIpublic static final JapaneseEra HEISEIThe singleton instance for the 'Heisei' era (1989-01-08 - 2019-04-30) which has the value 2.
REIWApublic static final JapaneseEra REIWAThe 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.
ofpublic static JapaneseEra of(int japaneseEra)Obtains an instance of
- The value
1is associated with the 'Showa' era, because it contains 1970-01-01 (ISO calendar system).
- The values
0are associated with two earlier eras, Meiji and Taisho, respectively.
- A value greater than
1is associated with a later era, beginning with Heisei (
japaneseEra- the era to represent
JapaneseErasingleton, not null
DateTimeException- if the value is invalid
- The value
JapaneseErawith 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
japaneseEra- the japaneseEra name; non-null
JapaneseErasingleton, never null
IllegalArgumentException- if there is not JapaneseEra with the specified name
valuespublic 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);
- an array of JapaneseEras
getDisplayNameGets 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 valueis returned.
getValuepublic int getValue()Gets the numeric era
rangeGets 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
ChronoFieldthen the query is implemented here. The
ERAfield returns the range. All other
ChronoFieldinstances will throw an
If the field is not a
ChronoField, then the result of this method is obtained by invoking
thisas 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:
- Specified by:
field- the field to query the range for, not null
- the range of valid values for the field, not null
DateTimeException- if the range for the field cannot be obtained
UnsupportedTemporalTypeException- if the unit is not supported