1 /*
   2  * Copyright (c) 2012, 2017, Oracle and/or its affiliates. All rights reserved.
   3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   4  *
   5  * This code is free software; you can redistribute it and/or modify it
   6  * under the terms of the GNU General Public License version 2 only, as
   7  * published by the Free Software Foundation.  Oracle designates this
   8  * particular file as subject to the "Classpath" exception as provided
   9  * by Oracle in the LICENSE file that accompanied this code.
  10  *
  11  * This code is distributed in the hope that it will be useful, but WITHOUT
  12  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  13  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  14  * version 2 for more details (a copy is included in the LICENSE file that
  15  * accompanied this code).
  16  *
  17  * You should have received a copy of the GNU General Public License version
  18  * 2 along with this work; if not, write to the Free Software Foundation,
  19  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  20  *
  21  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  22  * or visit www.oracle.com if you need additional information or have any
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  25 
  26 /*
  27  * This file is available under and governed by the GNU General Public
  28  * License version 2 only, as published by the Free Software Foundation.
  29  * However, the following notice accompanied the original version of this
  30  * file:
  31  *
  32  * Copyright (c) 2012, Stephen Colebourne & Michael Nascimento Santos
  33  *
  34  * All rights reserved.
  35  *
  36  * Redistribution and use in source and binary forms, with or without
  37  * modification, are permitted provided that the following conditions are met:
  38  *
  39  *  * Redistributions of source code must retain the above copyright notice,
  40  *    this list of conditions and the following disclaimer.
  41  *
  42  *  * Redistributions in binary form must reproduce the above copyright notice,
  43  *    this list of conditions and the following disclaimer in the documentation
  44  *    and/or other materials provided with the distribution.
  45  *
  46  *  * Neither the name of JSR-310 nor the names of its contributors
  47  *    may be used to endorse or promote products derived from this software
  48  *    without specific prior written permission.
  49  *
  50  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
  51  * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
  52  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
  53  * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR
  54  * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
  55  * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
  56  * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
  57  * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
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  59  * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
  60  * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  61  */
  62 package java.time.chrono;
  63 
  64 import static java.time.temporal.ChronoField.ERA;
  65 
  66 import java.time.DateTimeException;
  67 import java.time.format.DateTimeFormatterBuilder;
  68 import java.time.format.TextStyle;
  69 import java.util.Locale;
  70 
  71 /**
  72  * An era in the Minguo calendar system.
  73  * <p>
  74  * The Minguo calendar system has two eras.
  75  * The current era, for years from 1 onwards, is known as the 'Republic of China' era.
  76  * All previous years, zero or earlier in the proleptic count or one and greater
  77  * in the year-of-era count, are part of the 'Before Republic of China' era.
  78  *
  79  * <table class="striped" style="text-align:left">
  80  * <caption style="display:none">Minguo years and eras</caption>
  81  * <thead>
  82  * <tr>
  83  * <th>year-of-era</th>
  84  * <th>era</th>
  85  * <th>proleptic-year</th>
  86  * <th>ISO proleptic-year</th>
  87  * </tr>
  88  * </thead>
  89  * <tbody>
  90  * <tr>
  91  * <td>2</td><td>ROC</td><th scope="row">2</th><td>1913</td>
  92  * </tr>
  93  * <tr>
  94  * <td>1</td><td>ROC</td><th scope="row">1</th><td>1912</td>
  95  * </tr>
  96  * <tr>
  97  * <td>1</td><td>BEFORE_ROC</td><th scope="row">0</th><td>1911</td>
  98  * </tr>
  99  * <tr>
 100  * <td>2</td><td>BEFORE_ROC</td><th scope="row">-1</th><td>1910</td>
 101  * </tr>
 102  * </tbody>
 103  * </table>
 104  * <p>
 105  * <b>Do not use {@code ordinal()} to obtain the numeric representation of {@code MinguoEra}.
 106  * Use {@code getValue()} instead.</b>
 107  *
 108  * @implSpec
 109  * This is an immutable and thread-safe enum.
 110  *
 111  * @since 1.8
 112  */
 113 public enum MinguoEra implements Era {
 114 
 115     /**
 116      * The singleton instance for the era before the current one, 'Before Republic of China Era',
 117      * which has the numeric value 0.
 118      */
 119     BEFORE_ROC,
 120     /**
 121      * The singleton instance for the current era, 'Republic of China Era',
 122      * which has the numeric value 1.
 123      */
 124     ROC;
 125 
 126     //-----------------------------------------------------------------------
 127     /**
 128      * Obtains an instance of {@code MinguoEra} from an {@code int} value.
 129      * <p>
 130      * {@code MinguoEra} is an enum representing the Minguo eras of BEFORE_ROC/ROC.
 131      * This factory allows the enum to be obtained from the {@code int} value.
 132      *
 133      * @param minguoEra  the BEFORE_ROC/ROC value to represent, from 0 (BEFORE_ROC) to 1 (ROC)
 134      * @return the era singleton, not null
 135      * @throws DateTimeException if the value is invalid
 136      */
 137     public static MinguoEra of(int minguoEra) {
 138         switch (minguoEra) {
 139             case 0:
 140                 return BEFORE_ROC;
 141             case 1:
 142                 return ROC;
 143             default:
 144                 throw new DateTimeException("Invalid era: " + minguoEra);
 145         }
 146     }
 147 
 148     //-----------------------------------------------------------------------
 149     /**
 150      * Gets the numeric era {@code int} value.
 151      * <p>
 152      * The era BEFORE_ROC has the value 0, while the era ROC has the value 1.
 153      *
 154      * @return the era value, from 0 (BEFORE_ROC) to 1 (ROC)
 155      */
 156     @Override
 157     public int getValue() {
 158         return ordinal();
 159     }
 160 
 161     /**
 162      * {@inheritDoc}
 163      *
 164      * @param style {@inheritDoc}
 165      * @param locale {@inheritDoc}
 166      */
 167     @Override
 168     public String getDisplayName(TextStyle style, Locale locale) {
 169         return new DateTimeFormatterBuilder()
 170             .appendText(ERA, style)
 171             .toFormatter(locale)
 172             .withChronology(MinguoChronology.INSTANCE)
 173             .format(this == ROC ? MinguoDate.of(1, 1, 1) : MinguoDate.of(0, 1, 1));
 174     }
 175 
 176 }