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 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 class="striped" style="text-align:left"> 74 * <caption style="display:none">ISO years and eras</caption> 75 * <thead> 76 * <tr> 77 * <th scope="col">year-of-era</th> 78 * <th scope="col">era</th> 79 * <th scope="col">proleptic-year</th> 80 * </tr> 81 * </thead> 82 * <tbody> 83 * <tr> 84 * <td>2</td><td>CE</td><th scope="row">2</th> 85 * </tr> 86 * <tr> 87 * <td>1</td><td>CE</td><th scope="row">1</th> 88 * </tr> 89 * <tr> 90 * <td>1</td><td>BCE</td><th scope="row">0</th> 91 * </tr> 92 * <tr> 93 * <td>2</td><td>BCE</td><th scope="row">-1</th> 94 * </tr> 95 * </tbody> 96 * </table> 97 * <p> 98 * <b>Do not use {@code ordinal()} to obtain the numeric representation of {@code IsoEra}. 99 * Use {@code getValue()} instead.</b> 100 * 101 * @implSpec 102 * This is an immutable and thread-safe enum. 103 * 104 * @since 1.8 105 */ 106 public enum IsoEra implements Era { 107 108 /** 109 * The singleton instance for the era before the current one, 'Before Current Era', 110 * which has the numeric value 0. 111 */ 112 BCE, 113 /** 114 * The singleton instance for the current era, 'Current Era', 115 * which has the numeric value 1. 116 */ 117 CE; 118 119 //----------------------------------------------------------------------- 120 /** 121 * Obtains an instance of {@code IsoEra} from an {@code int} value. 122 * <p> 123 * {@code IsoEra} is an enum representing the ISO eras of BCE/CE. 124 * This factory allows the enum to be obtained from the {@code int} value. 125 * 126 * @param isoEra the BCE/CE value to represent, from 0 (BCE) to 1 (CE) 127 * @return the era singleton, not null 128 * @throws DateTimeException if the value is invalid 129 */ of(int isoEra)130 public static IsoEra of(int isoEra) { 131 switch (isoEra) { 132 case 0: 133 return BCE; 134 case 1: 135 return CE; 136 default: 137 throw new DateTimeException("Invalid era: " + isoEra); 138 } 139 } 140 141 //----------------------------------------------------------------------- 142 /** 143 * Gets the numeric era {@code int} value. 144 * <p> 145 * The era BCE has the value 0, while the era CE has the value 1. 146 * 147 * @return the era value, from 0 (BCE) to 1 (CE) 148 */ 149 @Override getValue()150 public int getValue() { 151 return ordinal(); 152 } 153 154 } 155