Alan Viverette | 3da604b | 2020-06-10 18:34:39 +0000 | [diff] [blame] | 1 | /* |
| 2 | * Copyright (c) 2012, 2013, 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 |
| 23 | * questions. |
| 24 | */ |
| 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 |
| 58 | * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING |
| 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 java.time.DateTimeException; |
| 65 | |
| 66 | /** |
| 67 | * An era in the ISO calendar system. |
| 68 | * <p> |
| 69 | * The ISO-8601 standard does not define eras. |
| 70 | * A definition has therefore been created with two eras - 'Current era' (CE) for |
| 71 | * years on or after 0001-01-01 (ISO), and 'Before current era' (BCE) for years before that. |
| 72 | * |
| 73 | * <table summary="ISO years and eras" cellpadding="2" cellspacing="3" border="0" > |
| 74 | * <thead> |
| 75 | * <tr class="tableSubHeadingColor"> |
| 76 | * <th class="colFirst" align="left">year-of-era</th> |
| 77 | * <th class="colFirst" align="left">era</th> |
| 78 | * <th class="colLast" align="left">proleptic-year</th> |
| 79 | * </tr> |
| 80 | * </thead> |
| 81 | * <tbody> |
| 82 | * <tr class="rowColor"> |
| 83 | * <td>2</td><td>CE</td><td>2</td> |
| 84 | * </tr> |
| 85 | * <tr class="altColor"> |
| 86 | * <td>1</td><td>CE</td><td>1</td> |
| 87 | * </tr> |
| 88 | * <tr class="rowColor"> |
| 89 | * <td>1</td><td>BCE</td><td>0</td> |
| 90 | * </tr> |
| 91 | * <tr class="altColor"> |
| 92 | * <td>2</td><td>BCE</td><td>-1</td> |
| 93 | * </tr> |
| 94 | * </tbody> |
| 95 | * </table> |
| 96 | * <p> |
| 97 | * <b>Do not use {@code ordinal()} to obtain the numeric representation of {@code IsoEra}. |
| 98 | * Use {@code getValue()} instead.</b> |
| 99 | * |
| 100 | * @implSpec |
| 101 | * This is an immutable and thread-safe enum. |
| 102 | * |
| 103 | * @since 1.8 |
| 104 | */ |
| 105 | public enum IsoEra implements Era { |
| 106 | |
| 107 | /** |
| 108 | * The singleton instance for the era before the current one, 'Before Current Era', |
| 109 | * which has the numeric value 0. |
| 110 | */ |
| 111 | BCE, |
| 112 | /** |
| 113 | * The singleton instance for the current era, 'Current Era', |
| 114 | * which has the numeric value 1. |
| 115 | */ |
| 116 | CE; |
| 117 | |
| 118 | //----------------------------------------------------------------------- |
| 119 | /** |
| 120 | * Obtains an instance of {@code IsoEra} from an {@code int} value. |
| 121 | * <p> |
| 122 | * {@code IsoEra} is an enum representing the ISO eras of BCE/CE. |
| 123 | * This factory allows the enum to be obtained from the {@code int} value. |
| 124 | * |
| 125 | * @param isoEra the BCE/CE value to represent, from 0 (BCE) to 1 (CE) |
| 126 | * @return the era singleton, not null |
| 127 | * @throws DateTimeException if the value is invalid |
| 128 | */ |
| 129 | public static IsoEra of(int isoEra) { |
| 130 | switch (isoEra) { |
| 131 | case 0: |
| 132 | return BCE; |
| 133 | case 1: |
| 134 | return CE; |
| 135 | default: |
| 136 | throw new DateTimeException("Invalid era: " + isoEra); |
| 137 | } |
| 138 | } |
| 139 | |
| 140 | //----------------------------------------------------------------------- |
| 141 | /** |
| 142 | * Gets the numeric era {@code int} value. |
| 143 | * <p> |
| 144 | * The era BCE has the value 0, while the era CE has the value 1. |
| 145 | * |
| 146 | * @return the era value, from 0 (BCE) to 1 (CE) |
| 147 | */ |
| 148 | @Override |
| 149 | public int getValue() { |
| 150 | return ordinal(); |
| 151 | } |
| 152 | |
| 153 | } |