org.threeten.bp.chrono.JapaneseEra.scala Maven / Gradle / Ivy

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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
 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR
 * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
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 * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */
package org.threeten.bp.chrono

import java.io.Serializable
import java.util.{ Arrays, Objects }
import java.util.concurrent.atomic.AtomicReference

import org.threeten.bp.DateTimeException
import org.threeten.bp.LocalDate
import org.threeten.bp.temporal.ChronoField
import org.threeten.bp.temporal.TemporalField
import org.threeten.bp.temporal.ValueRange

import scala.annotation.meta.field

object JapaneseEra {
  private[chrono] val ERA_OFFSET: Int                  = 2
  private[chrono] val ERA_NAMES: Array[String]         = Array("Meiji", "Taisho", "Showa", "Heisei")
  private[chrono] val ERA_ABBREVIATIONS: Array[String] = Array("M", "T", "S", "H")

  /**
   * The singleton instance for the 'Meiji' era (1868-09-08 - 1912-07-29) which has the value -1.
   */
  lazy val MEIJI: JapaneseEra = new JapaneseEra(-1, LocalDate.of(1868, 9, 8), "Meiji")

  /**
   * The singleton instance for the 'Taisho' era (1912-07-30 - 1926-12-24) which has the value 0.
   */
  lazy val TAISHO: JapaneseEra = new JapaneseEra(0, LocalDate.of(1912, 7, 30), "Taisho")

  /**
   * The singleton instance for the 'Showa' era (1926-12-25 - 1989-01-07) which has the value 1.
   */
  lazy val SHOWA: JapaneseEra = new JapaneseEra(1, LocalDate.of(1926, 12, 25), "Showa")

  /**
   * The singleton instance for the 'Heisei' era (1989-01-08 - current) which has the value 2.
   */
  lazy val HEISEI: JapaneseEra = new JapaneseEra(2, LocalDate.of(1989, 1, 8), "Heisei")

  /**
   * The singleton instance for the 'Reiwa' era (2019-05-01 - current) which has the value 3.
   */
  lazy val REIWA = new JapaneseEra(3, LocalDate.of(2019, 5, 1), "Reiwa")

  /**
   * The value of the additional era.
   */
  private[chrono] val ADDITIONAL_VALUE: Int = 4

  private[chrono] lazy val KNOWN_ERAS: AtomicReference[Array[JapaneseEra]] = new AtomicReference(
    Array(MEIJI, TAISHO, SHOWA, HEISEI, REIWA)
  )

  /**
   * Obtains an instance of {@code JapaneseEra} from an {@code int} value.
   *
   * The {@link #SHOWA} era that contains 1970-01-01 (ISO calendar system) has the value 1 Later era
   * is numbered 2 ({@link #HEISEI}). Earlier eras are numbered 0 ({@link #TAISHO}),
   * -1 ({@link #MEIJI}), only Meiji and later eras are supported.
   *
   * @param japaneseEra
   *   the era to represent
   * @return
   *   the { @code JapaneseEra} singleton, not null
   * @throws DateTimeException
   *   if the value is invalid
   */
  def of(japaneseEra: Int): JapaneseEra = {
    val known = KNOWN_ERAS.get
    if (japaneseEra < MEIJI.eraValue || japaneseEra > known(known.length - 1).eraValue)
      throw new DateTimeException("japaneseEra is invalid")
    known(ordinal(japaneseEra))
  }

  /**
   * Returns the {@code JapaneseEra} with the name.
   *
   * The string must match exactly the name of the era. (Extraneous whitespace characters are not
   * permitted.)
   *
   * @param japaneseEra
   *   the japaneseEra name; non-null
   * @return
   *   the { @code JapaneseEra} singleton, never null
   * @throws IllegalArgumentException
   *   if there is not JapaneseEra with the specified name
   */
  def valueOf(japaneseEra: String): JapaneseEra = {
    Objects.requireNonNull(japaneseEra, "japaneseEra")
    for (era <- KNOWN_ERAS.get)
      if (japaneseEra == era.name)
        return era
    throw new IllegalArgumentException(s"Era not found: $japaneseEra")
  }

  /**
   * Returns an array of JapaneseEras.
   *
   * This method may be used to iterate over the JapaneseEras as follows:  for (JapaneseEra c :
   * JapaneseEra.values()) System.out.println(c); 
   *
   * @return
   *   an array of JapaneseEras
   */
  def values: Array[JapaneseEra] = Arrays.copyOf(KNOWN_ERAS.get, KNOWN_ERAS.get.length)

  /**
   * Obtains an instance of {@code JapaneseEra} from a date.
   *
   * @param date
   *   the date, not null
   * @return
   *   the Era singleton, never null
   */
  private[chrono] def from(date: LocalDate): JapaneseEra = {
    if (date.isBefore(MEIJI.since))
      throw new DateTimeException(s"Date too early: $date")
    var i: Int = KNOWN_ERAS.get.length - 1
    while (i >= 0) {
      val era: JapaneseEra = KNOWN_ERAS.get.apply(i)
      if (date.compareTo(era.since) >= 0)
        return era
      i -= 1
    }
    null
  }

  /**
   * Returns the index into the arrays from the Era value. the eraValue is a valid Era number, -999,
   * -1..2.
   * @param eraValue
   *   the era value to convert to the index
   * @return
   *   the index of the current Era
   */
  private def ordinal(eraValue: Int): Int = eraValue + 1

}

/**
 * An era in the Japanese Imperial calendar system.
 *
 * This class defines the valid eras for the Japanese chronology. Japan introduced the Gregorian
 * calendar starting with Meiji 6. Only Meiji and later eras are supported; dates before Meiji 6,
 * January 1 are not supported.  The four supported eras are hard-coded. A single additional era
 * may be registered using {@link #registerEra(LocalDate, String)}.
 *
 * 
Specification for implementors This class is immutable and thread-safe.
 *
 * @constructor
 *   Creates an instance.
 *
 * @param eraValue
 *   the era value, validated
 * @param since
 *   the date representing the first date of the era, validated not null
 */
final class JapaneseEra private[chrono] (
  private val eraValue:                          Int,
  @(transient @field) private[chrono] val since: LocalDate,
  @(transient @field) private val name:          String
) extends Era
    with Serializable {

  /**
   * Returns the start date of the era.
   * @return
   *   the start date
   */
  private[chrono] def startDate: LocalDate = since

  /**
   * Returns the end date of the era.
   * @return
   *   the end date
   */
  private[chrono] def endDate: LocalDate = {
    val ordinal: Int             = JapaneseEra.ordinal(eraValue)
    val eras: Array[JapaneseEra] = JapaneseEra.values
    if (ordinal >= eras.length - 1) LocalDate.MAX
    else eras(ordinal + 1).startDate.minusDays(1)
  }

  /**
   * Returns the numeric value of this {@code JapaneseEra}.
   *
   * The {@link #SHOWA} era that contains 1970-01-01 (ISO calendar system) has the value 1. Later
   * eras are numbered from 2 ({@link #HEISEI}). Earlier eras are numbered 0 ({@link #TAISHO}) and
   * -1 ({@link #MEIJI}).
   *
   * @return
   *   the era value
   */
  def getValue: Int = eraValue

  override def range(field: TemporalField): ValueRange =
    if (field eq ChronoField.ERA) JapaneseChronology.INSTANCE.range(ChronoField.ERA)
    else super.range(field)

  override def toString: String = name

}