* This class defines the valid eras for the Japanese chronology. - * Only Meiji (1868-09-08 - 1912-07-29) and later eras are supported. - * Japan introduced the Gregorian calendar since Meiji 6. The dates - * between Meiji 1 - 5 are not historically correct. - * The older eras are recognized as Seireki (Western calendar) era, - * and the year of era of Seireki is proleptic Gregorian year. - * (The Julian to Gregorian transition is not supported.) + * 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. * * @implSpec * This class is immutable and thread-safe. @@ -100,17 +98,12 @@ implements Era, Serializable { // The offset value to 0-based index from the era value. - // i.e., getValue() + ERA_OFFSET == 0-based index; except that -999 is mapped to zero + // i.e., getValue() + ERA_OFFSET == 0-based index static final int ERA_OFFSET = 2; static final sun.util.calendar.Era[] ERA_CONFIG; /** - * The singleton instance for the before Meiji era ( - 1868-09-07) - * which has the value -999. - */ - public static final JapaneseEra SEIREKI = new JapaneseEra(-999, LocalDate.MIN); - /** * The singleton instance for the 'Meiji' era (1868-09-08 - 1912-07-29) * which has the value -1. */ @@ -144,17 +137,13 @@ private static final JapaneseEra[] KNOWN_ERAS; static { - sun.util.calendar.Era[] sunEras = JapaneseChronology.JCAL.getEras(); - ERA_CONFIG = new sun.util.calendar.Era[sunEras.length + 1]; - for (int i = 1; i < ERA_CONFIG.length; i++) { - ERA_CONFIG[i] = sunEras[i - 1]; - } + ERA_CONFIG = JapaneseChronology.JCAL.getEras(); + KNOWN_ERAS = new JapaneseEra[ERA_CONFIG.length]; - KNOWN_ERAS[0] = SEIREKI; - KNOWN_ERAS[1] = MEIJI; - KNOWN_ERAS[2] = TAISHO; - KNOWN_ERAS[3] = SHOWA; - KNOWN_ERAS[4] = HEISEI; + KNOWN_ERAS[0] = MEIJI; + KNOWN_ERAS[1] = TAISHO; + KNOWN_ERAS[2] = SHOWA; + KNOWN_ERAS[3] = HEISEI; for (int i = N_ERA_CONSTANTS; i < ERA_CONFIG.length; i++) { CalendarDate date = ERA_CONFIG[i].getSinceDate(); LocalDate isoDate = LocalDate.of(date.getYear(), date.getMonth(), date.getDayOfMonth()); @@ -203,10 +192,8 @@ //----------------------------------------------------------------------- /** * Returns the Sun private Era instance corresponding to this {@code JapaneseEra}. - * SEIREKI doesn't have its corresponding one. * - * @return the Sun private Era instance for this {@code JapaneseEra}, - * or null for SEIREKI. + * @return the Sun private Era instance for this {@code JapaneseEra}. */ sun.util.calendar.Era getPrivateEra() { return ERA_CONFIG[ordinal(eraValue)]; @@ -218,16 +205,14 @@ *
* 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. The prior to Meiji, - * {@link #SEIREKI} is used. + * -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 */ public static JapaneseEra of(int japaneseEra) { - if (japaneseEra != SEIREKI.eraValue && - (japaneseEra < MEIJI.eraValue || japaneseEra > HEISEI.eraValue)) { + if (japaneseEra < MEIJI.eraValue || japaneseEra > HEISEI.eraValue) { throw new DateTimeException("Invalid era: " + japaneseEra); } return KNOWN_ERAS[ordinal(japaneseEra)]; @@ -276,22 +261,25 @@ * @return the Era singleton, never null */ static JapaneseEra from(LocalDate date) { + if (date.isBefore(MEIJI_6_ISODATE)) { + throw new DateTimeException("JapaneseDate before Meiji 6 are not supported"); + } for (int i = KNOWN_ERAS.length - 1; i > 0; i--) { JapaneseEra era = KNOWN_ERAS[i]; if (date.compareTo(era.since) >= 0) { return era; } } - return SEIREKI; + return null; } static JapaneseEra toJapaneseEra(sun.util.calendar.Era privateEra) { - for (int i = ERA_CONFIG.length - 1; i > 0; i--) { + for (int i = ERA_CONFIG.length - 1; i >= 0; i--) { if (ERA_CONFIG[i].equals(privateEra)) { return KNOWN_ERAS[i]; } } - return SEIREKI; + return null; } static sun.util.calendar.Era privateEraFrom(LocalDate isoDate) { @@ -306,13 +294,13 @@ /** * Returns the index into the arrays from the Era value. - * the eraValue is a valid Era number, -999, -1..2. + * the eraValue is a valid Era number, -1..2. * * @param eraValue the era value to convert to the index * @return the index of the current Era */ private static int ordinal(int eraValue) { - return (eraValue == SEIREKI.eraValue) ? 0 : eraValue + ERA_OFFSET; + return eraValue + ERA_OFFSET - 1; } //----------------------------------------------------------------------- @@ -321,7 +309,7 @@ *
* 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}), -1 ({@link #MEIJI}), and -999 ({@link #SEIREKI}). + * Earlier eras are numbered 0 ({@link #TAISHO}), -1 ({@link #MEIJI})). * * @return the era value */ @@ -374,11 +362,7 @@ } String getName() { - int index = ordinal(getValue()); - if (index == 0) { - return "Seireki"; - } - return ERA_CONFIG[index].getName(); + return ERA_CONFIG[ordinal(getValue())].getName(); } @Override