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/*
* Copyright (c) 2007-present, Stephen Colebourne & Michael Nascimento Santos
*
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are met:
*
* * Redistributions of source code must retain the above copyright notice,
* this list of conditions and the following disclaimer.
*
* * Redistributions in binary form must reproduce the above copyright notice,
* this list of conditions and the following disclaimer in the documentation
* and/or other materials provided with the distribution.
*
* * Neither the name of JSR-310 nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
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package org.threeten.bp.chrono;
import java.util.Locale;
import org.threeten.bp.format.TextStyle;
import org.threeten.bp.temporal.TemporalAccessor;
import org.threeten.bp.temporal.TemporalAdjuster;
/**
* An era of the time-line.
*
* Most calendar systems have a single epoch dividing the time-line into two eras.
* However, some calendar systems, have multiple eras, such as one for the reign
* of each leader.
* In all cases, the era is conceptually the largest division of the time-line.
* Each chronology defines the Era's that are known Eras and a
* {@link Chronology#eras Chrono.eras} to get the valid eras.
*
* For example, the Thai Buddhist calendar system divides time into two eras,
* before and after a single date. By contrast, the Japanese calendar system
* has one era for the reign of each Emperor.
*
* Instances of {@code Era} may be compared using the {@code ==} operator.
*
*
Specification for implementors
* This interface must be implemented with care to ensure other classes operate correctly.
* All implementations must be singletons - final, immutable and thread-safe.
* It is recommended to use an enum whenever possible.
*/
public interface Era extends TemporalAccessor, TemporalAdjuster {
/**
* Gets the numeric value associated with the era as defined by the chronology.
* Each chronology defines the predefined Eras and methods to list the Eras
* of the chronology.
*
* All fields, including eras, have an associated numeric value.
* The meaning of the numeric value for era is determined by the chronology
* according to these principles:
*
* - The era in use at the epoch 1970-01-01 (ISO) has the value 1.
*
- Later eras have sequentially higher values.
*
- Earlier eras have sequentially lower values, which may be negative.
*
*
* @return the numeric era value
*/
int getValue();
/**
* Gets the textual representation of this era.
*
* This returns the textual name used to identify the era.
* The parameters control the style of the returned text and the locale.
*
* If no textual mapping is found then the {@link #getValue() numeric value} is returned.
*
* @param style the style of the text required, not null
* @param locale the locale to use, not null
* @return the text value of the era, not null
*/
String getDisplayName(TextStyle style, Locale locale);
}