ThaiBuddhistEra.java

/*
 * Copyright (c) 2012, 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 java.time.chrono.global;

import static java.time.calendrical.ChronoField.ERA;

import java.io.DataInput;
import java.io.DataOutput;
import java.io.IOException;
import java.time.DateTimeException;
import java.time.calendrical.ChronoField;
import java.time.calendrical.DateTime;
import java.time.calendrical.DateTimeField;
import java.time.calendrical.DateTimeValueRange;
import java.time.chrono.ChronoLocalDate;
import java.time.chrono.Era;
import java.time.format.DateTimeFormatterBuilder;
import java.time.format.TextStyle;
import java.util.Locale;

/**
 * An era in the Thai Buddhist calendar system.
 * <p>
 * The Thai Buddhist calendar system has two eras.
 * <p>
 * <b>Do not use ordinal() to obtain the numeric representation of a ThaiBuddhistEra instance. Use getValue()
 * instead.</b>
 * 
 * <h4>Implementation notes</h4> This is an immutable and thread-safe enum.
 */
enum ThaiBuddhistEra implements Era<ThaiBuddhistChrono> {

  /**
   * The singleton instance for the era before the current one, 'Before Buddhist Era', which has the value 0.
   */
  BEFORE_BE,
  /**
   * The singleton instance for the current era, 'Buddhist Era', which has the value 1.
   */
  BE;

  // -----------------------------------------------------------------------
  /**
   * Obtains an instance of {@code ThaiBuddhistEra} from a value.
   * <p>
   * The current era (from ISO year -543 onwards) has the value 1 The previous era has the value 0.
   * 
   * @param thaiBuddhistEra the era to represent, from 0 to 1
   * @return the BuddhistEra singleton, never null
   * @throws IllegalCalendarFieldValueException if the era is invalid
   */
  public static ThaiBuddhistEra of(int thaiBuddhistEra) {

    switch (thaiBuddhistEra) {
      case 0:
        return BEFORE_BE;
      case 1:
        return BE;
      default :
        throw new DateTimeException("Era is not valid for ThaiBuddhistEra");
    }
  }

  // -----------------------------------------------------------------------
  /**
   * Gets the era numeric value.
   * <p>
   * The current era (from ISO year -543 onwards) has the value 1 The previous era has the value 0.
   * 
   * @return the era value, from 0 (BEFORE_BE) to 1 (BE)
   */
  @Override
  public int getValue() {

    return ordinal();
  }

  @Override
  public ThaiBuddhistChrono getChrono() {

    return ThaiBuddhistChrono.INSTANCE;
  }

  // JDK8 default methods:
  // -----------------------------------------------------------------------
  @Override
  public ChronoLocalDate<ThaiBuddhistChrono> date(int year, int month, int day) {

    return getChrono().date(this, year, month, day);
  }

  @Override
  public ChronoLocalDate<ThaiBuddhistChrono> dateYearDay(int year, int dayOfYear) {

    return getChrono().dateYearDay(this, year, dayOfYear);
  }

  // -----------------------------------------------------------------------
  @Override
  public boolean isSupported(DateTimeField field) {

    if (field instanceof ChronoField) {
      return field == ERA;
    }
    return field != null && field.doIsSupported(this);
  }

  @Override
  public DateTimeValueRange range(DateTimeField field) {

    if (field == ERA) {
      return field.range();
    } else if (field instanceof ChronoField) {
      throw new DateTimeException("Unsupported field: " + field.getName());
    }
    return field.doRange(this);
  }

  @Override
  public int get(DateTimeField field) {

    if (field == ERA) {
      return getValue();
    }
    return range(field).checkValidIntValue(getLong(field), field);
  }

  @Override
  public long getLong(DateTimeField field) {

    if (field == ERA) {
      return getValue();
    } else if (field instanceof ChronoField) {
      throw new DateTimeException("Unsupported field: " + field.getName());
    }
    return field.doGet(this);
  }

  // -------------------------------------------------------------------------
  @Override
  public DateTime doWithAdjustment(DateTime dateTime) {

    return dateTime.with(ERA, getValue());
  }

  @SuppressWarnings("unchecked")
  @Override
  public <R> R query(Query<R> query) {

    if (query == Query.CHRONO) {
      return (R) getChrono();
    }
    return query.doQuery(this);
  }

  // -----------------------------------------------------------------------
  @Override
  public String getText(TextStyle style, Locale locale) {

    return new DateTimeFormatterBuilder().appendText(ERA, style).toFormatter(locale).print(this);
  }

  // -----------------------------------------------------------------------
  private Object writeReplace() {

    return new Ser(Ser.THAIBUDDHIST_ERA_TYPE, this);
  }

  void writeExternal(DataOutput out) throws IOException {

    out.writeByte(getValue());
  }

  static ThaiBuddhistEra readExternal(DataInput in) throws IOException {

    byte eraValue = in.readByte();
    return ThaiBuddhistEra.of(eraValue);
  }

}