1 /* |
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2 * Copyright (c) 2012, 2013, Oracle and/or its affiliates. All rights reserved. |
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3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. |
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4 * |
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5 * This code is free software; you can redistribute it and/or modify it |
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6 * under the terms of the GNU General Public License version 2 only, as |
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7 * published by the Free Software Foundation. Oracle designates this |
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8 * particular file as subject to the "Classpath" exception as provided |
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9 * by Oracle in the LICENSE file that accompanied this code. |
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10 * |
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11 * This code is distributed in the hope that it will be useful, but WITHOUT |
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12 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or |
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13 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License |
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14 * version 2 for more details (a copy is included in the LICENSE file that |
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15 * accompanied this code). |
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16 * |
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17 * You should have received a copy of the GNU General Public License version |
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18 * 2 along with this work; if not, write to the Free Software Foundation, |
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19 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. |
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20 * |
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21 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA |
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22 * or visit www.oracle.com if you need additional information or have any |
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23 * questions. |
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24 */ |
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25 |
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26 /* |
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27 * This file is available under and governed by the GNU General Public |
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28 * License version 2 only, as published by the Free Software Foundation. |
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29 * However, the following notice accompanied the original version of this |
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30 * file: |
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31 * |
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32 * Copyright (c) 2007-2012, Stephen Colebourne & Michael Nascimento Santos |
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33 * |
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34 * All rights reserved. |
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35 * |
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36 * Redistribution and use in source and binary forms, with or without |
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37 * modification, are permitted provided that the following conditions are met: |
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38 * |
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39 * * Redistributions of source code must retain the above copyright notice, |
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40 * this list of conditions and the following disclaimer. |
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41 * |
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42 * * Redistributions in binary form must reproduce the above copyright notice, |
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43 * this list of conditions and the following disclaimer in the documentation |
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44 * and/or other materials provided with the distribution. |
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45 * |
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46 * * Neither the name of JSR-310 nor the names of its contributors |
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47 * may be used to endorse or promote products derived from this software |
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48 * without specific prior written permission. |
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49 * |
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50 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS |
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51 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT |
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52 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR |
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53 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR |
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54 * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, |
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55 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, |
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56 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR |
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57 * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF |
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58 * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING |
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59 * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS |
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60 * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. |
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61 */ |
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62 package java.time.temporal; |
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63 |
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64 import static java.time.temporal.ChronoField.ERA; |
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65 import static java.time.temporal.ChronoField.YEAR; |
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66 import static java.time.temporal.ChronoField.YEAR_OF_ERA; |
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67 import static java.time.temporal.ChronoUnit.YEARS; |
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68 |
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69 import java.io.DataInput; |
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70 import java.io.DataOutput; |
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71 import java.io.IOException; |
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72 import java.io.InvalidObjectException; |
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73 import java.io.ObjectStreamException; |
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74 import java.io.Serializable; |
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75 import java.time.Clock; |
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76 import java.time.DateTimeException; |
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77 import java.time.LocalDate; |
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78 import java.time.Month; |
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79 import java.time.ZoneId; |
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80 import java.time.format.DateTimeFormatter; |
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81 import java.time.format.DateTimeFormatterBuilder; |
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82 import java.time.format.DateTimeParseException; |
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83 import java.time.format.SignStyle; |
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84 import java.util.Objects; |
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85 |
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86 /** |
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87 * A year in the ISO-8601 calendar system, such as {@code 2007}. |
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88 * <p> |
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89 * {@code Year} is an immutable date-time object that represents a year. |
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90 * Any field that can be derived from a year can be obtained. |
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91 * <p> |
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92 * <b>Note that years in the ISO chronology only align with years in the |
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93 * Gregorian-Julian system for modern years. Parts of Russia did not switch to the |
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94 * modern Gregorian/ISO rules until 1920. |
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95 * As such, historical years must be treated with caution.</b> |
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96 * <p> |
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97 * This class does not store or represent a month, day, time or time-zone. |
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98 * For example, the value "2007" can be stored in a {@code Year}. |
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99 * <p> |
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100 * Years represented by this class follow the ISO-8601 standard and use |
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101 * the proleptic numbering system. Year 1 is preceded by year 0, then by year -1. |
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102 * <p> |
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103 * The ISO-8601 calendar system is the modern civil calendar system used today |
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104 * in most of the world. It is equivalent to the proleptic Gregorian calendar |
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105 * system, in which today's rules for leap years are applied for all time. |
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106 * For most applications written today, the ISO-8601 rules are entirely suitable. |
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107 * However, any application that makes use of historical dates, and requires them |
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108 * to be accurate will find the ISO-8601 approach unsuitable. |
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109 * |
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110 * <h3>Specification for implementors</h3> |
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111 * This class is immutable and thread-safe. |
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112 * |
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113 * @since 1.8 |
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114 */ |
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115 public final class Year |
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116 implements Temporal, TemporalAdjuster, Comparable<Year>, Serializable { |
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117 |
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118 /** |
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119 * The minimum supported year, '-999,999,999'. |
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120 */ |
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121 public static final int MIN_VALUE = -999_999_999; |
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122 /** |
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123 * The maximum supported year, '+999,999,999'. |
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124 */ |
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125 public static final int MAX_VALUE = 999_999_999; |
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126 |
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127 /** |
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128 * Serialization version. |
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129 */ |
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130 private static final long serialVersionUID = -23038383694477807L; |
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131 /** |
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132 * Parser. |
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133 */ |
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134 private static final DateTimeFormatter PARSER = new DateTimeFormatterBuilder() |
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135 .appendValue(YEAR, 4, 10, SignStyle.EXCEEDS_PAD) |
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136 .toFormatter(); |
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137 |
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138 /** |
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139 * The year being represented. |
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140 */ |
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141 private final int year; |
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142 |
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143 //----------------------------------------------------------------------- |
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144 /** |
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145 * Obtains the current year from the system clock in the default time-zone. |
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146 * <p> |
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147 * This will query the {@link java.time.Clock#systemDefaultZone() system clock} in the default |
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148 * time-zone to obtain the current year. |
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149 * <p> |
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150 * Using this method will prevent the ability to use an alternate clock for testing |
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151 * because the clock is hard-coded. |
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152 * |
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153 * @return the current year using the system clock and default time-zone, not null |
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154 */ |
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155 public static Year now() { |
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156 return now(Clock.systemDefaultZone()); |
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157 } |
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158 |
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159 /** |
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160 * Obtains the current year from the system clock in the specified time-zone. |
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161 * <p> |
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162 * This will query the {@link Clock#system(java.time.ZoneId) system clock} to obtain the current year. |
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163 * Specifying the time-zone avoids dependence on the default time-zone. |
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164 * <p> |
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165 * Using this method will prevent the ability to use an alternate clock for testing |
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166 * because the clock is hard-coded. |
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167 * |
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168 * @param zone the zone ID to use, not null |
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169 * @return the current year using the system clock, not null |
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170 */ |
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171 public static Year now(ZoneId zone) { |
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172 return now(Clock.system(zone)); |
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173 } |
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174 |
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175 /** |
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176 * Obtains the current year from the specified clock. |
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177 * <p> |
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178 * This will query the specified clock to obtain the current year. |
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179 * Using this method allows the use of an alternate clock for testing. |
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180 * The alternate clock may be introduced using {@link Clock dependency injection}. |
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181 * |
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182 * @param clock the clock to use, not null |
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183 * @return the current year, not null |
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184 */ |
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185 public static Year now(Clock clock) { |
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186 final LocalDate now = LocalDate.now(clock); // called once |
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187 return Year.of(now.getYear()); |
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188 } |
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189 |
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190 //----------------------------------------------------------------------- |
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191 /** |
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192 * Obtains an instance of {@code Year}. |
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193 * <p> |
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194 * This method accepts a year value from the proleptic ISO calendar system. |
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195 * <p> |
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196 * The year 2AD/CE is represented by 2.<br> |
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197 * The year 1AD/CE is represented by 1.<br> |
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198 * The year 1BC/BCE is represented by 0.<br> |
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199 * The year 2BC/BCE is represented by -1.<br> |
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200 * |
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201 * @param isoYear the ISO proleptic year to represent, from {@code MIN_VALUE} to {@code MAX_VALUE} |
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202 * @return the year, not null |
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203 * @throws DateTimeException if the field is invalid |
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204 */ |
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205 public static Year of(int isoYear) { |
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206 YEAR.checkValidValue(isoYear); |
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207 return new Year(isoYear); |
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208 } |
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209 |
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210 //----------------------------------------------------------------------- |
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211 /** |
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212 * Obtains an instance of {@code Year} from a temporal object. |
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213 * <p> |
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214 * A {@code TemporalAccessor} represents some form of date and time information. |
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215 * This factory converts the arbitrary temporal object to an instance of {@code Year}. |
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216 * <p> |
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217 * The conversion extracts the {@link ChronoField#YEAR year} field. |
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218 * The extraction is only permitted if the temporal object has an ISO |
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219 * chronology, or can be converted to a {@code LocalDate}. |
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220 * <p> |
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221 * This method matches the signature of the functional interface {@link TemporalQuery} |
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222 * allowing it to be used in queries via method reference, {@code Year::from}. |
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223 * |
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224 * @param temporal the temporal object to convert, not null |
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225 * @return the year, not null |
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226 * @throws DateTimeException if unable to convert to a {@code Year} |
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227 */ |
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228 public static Year from(TemporalAccessor temporal) { |
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229 if (temporal instanceof Year) { |
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230 return (Year) temporal; |
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231 } |
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232 try { |
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233 if (ISOChrono.INSTANCE.equals(Chrono.from(temporal)) == false) { |
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234 temporal = LocalDate.from(temporal); |
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235 } |
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236 return of(temporal.get(YEAR)); |
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237 } catch (DateTimeException ex) { |
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238 throw new DateTimeException("Unable to obtain Year from TemporalAccessor: " + temporal.getClass(), ex); |
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239 } |
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240 } |
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241 |
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242 //----------------------------------------------------------------------- |
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243 /** |
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244 * Obtains an instance of {@code Year} from a text string such as {@code 2007}. |
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245 * <p> |
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246 * The string must represent a valid year. |
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247 * Years outside the range 0000 to 9999 must be prefixed by the plus or minus symbol. |
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248 * |
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249 * @param text the text to parse such as "2007", not null |
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250 * @return the parsed year, not null |
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251 * @throws DateTimeParseException if the text cannot be parsed |
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252 */ |
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253 public static Year parse(CharSequence text) { |
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254 return parse(text, PARSER); |
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255 } |
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256 |
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257 /** |
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258 * Obtains an instance of {@code Year} from a text string using a specific formatter. |
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259 * <p> |
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260 * The text is parsed using the formatter, returning a year. |
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261 * |
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262 * @param text the text to parse, not null |
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263 * @param formatter the formatter to use, not null |
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264 * @return the parsed year, not null |
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265 * @throws DateTimeParseException if the text cannot be parsed |
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266 */ |
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267 public static Year parse(CharSequence text, DateTimeFormatter formatter) { |
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268 Objects.requireNonNull(formatter, "formatter"); |
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269 return formatter.parse(text, Year::from); |
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270 } |
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271 |
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272 //------------------------------------------------------------------------- |
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273 /** |
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274 * Checks if the year is a leap year, according to the ISO proleptic |
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275 * calendar system rules. |
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276 * <p> |
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277 * This method applies the current rules for leap years across the whole time-line. |
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278 * In general, a year is a leap year if it is divisible by four without |
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279 * remainder. However, years divisible by 100, are not leap years, with |
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280 * the exception of years divisible by 400 which are. |
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281 * <p> |
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282 * For example, 1904 is a leap year it is divisible by 4. |
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283 * 1900 was not a leap year as it is divisible by 100, however 2000 was a |
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284 * leap year as it is divisible by 400. |
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285 * <p> |
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286 * The calculation is proleptic - applying the same rules into the far future and far past. |
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287 * This is historically inaccurate, but is correct for the ISO-8601 standard. |
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288 * |
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289 * @param year the year to check |
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290 * @return true if the year is leap, false otherwise |
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291 */ |
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292 public static boolean isLeap(long year) { |
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293 return ((year & 3) == 0) && ((year % 100) != 0 || (year % 400) == 0); |
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294 } |
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295 |
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296 //----------------------------------------------------------------------- |
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297 /** |
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298 * Constructor. |
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299 * |
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300 * @param year the year to represent |
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301 */ |
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302 private Year(int year) { |
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303 this.year = year; |
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304 } |
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305 |
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306 //----------------------------------------------------------------------- |
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307 /** |
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308 * Gets the year value. |
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309 * <p> |
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310 * The year returned by this method is proleptic as per {@code get(YEAR)}. |
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311 * |
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312 * @return the year, {@code MIN_VALUE} to {@code MAX_VALUE} |
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313 */ |
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314 public int getValue() { |
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315 return year; |
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316 } |
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317 |
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318 //----------------------------------------------------------------------- |
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319 /** |
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320 * Checks if the specified field is supported. |
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321 * <p> |
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322 * This checks if this year can be queried for the specified field. |
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323 * If false, then calling the {@link #range(TemporalField) range} and |
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324 * {@link #get(TemporalField) get} methods will throw an exception. |
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325 * <p> |
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326 * If the field is a {@link ChronoField} then the query is implemented here. |
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327 * The {@link #isSupported(TemporalField) supported fields} will return valid |
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328 * values based on this date-time. |
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329 * The supported fields are: |
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330 * <ul> |
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331 * <li>{@code YEAR_OF_ERA} |
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332 * <li>{@code YEAR} |
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333 * <li>{@code ERA} |
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334 * </ul> |
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335 * All other {@code ChronoField} instances will return false. |
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336 * <p> |
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337 * If the field is not a {@code ChronoField}, then the result of this method |
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338 * is obtained by invoking {@code TemporalField.doIsSupported(TemporalAccessor)} |
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339 * passing {@code this} as the argument. |
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340 * Whether the field is supported is determined by the field. |
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341 * |
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342 * @param field the field to check, null returns false |
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343 * @return true if the field is supported on this year, false if not |
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344 */ |
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345 @Override |
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346 public boolean isSupported(TemporalField field) { |
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347 if (field instanceof ChronoField) { |
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348 return field == YEAR || field == YEAR_OF_ERA || field == ERA; |
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349 } |
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350 return field != null && field.doIsSupported(this); |
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351 } |
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352 |
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353 /** |
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354 * Gets the range of valid values for the specified field. |
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355 * <p> |
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356 * The range object expresses the minimum and maximum valid values for a field. |
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357 * This year is used to enhance the accuracy of the returned range. |
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358 * If it is not possible to return the range, because the field is not supported |
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359 * or for some other reason, an exception is thrown. |
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360 * <p> |
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361 * If the field is a {@link ChronoField} then the query is implemented here. |
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362 * The {@link #isSupported(TemporalField) supported fields} will return |
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363 * appropriate range instances. |
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364 * All other {@code ChronoField} instances will throw a {@code DateTimeException}. |
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365 * <p> |
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366 * If the field is not a {@code ChronoField}, then the result of this method |
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367 * is obtained by invoking {@code TemporalField.doRange(TemporalAccessor)} |
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368 * passing {@code this} as the argument. |
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369 * Whether the range can be obtained is determined by the field. |
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370 * |
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371 * @param field the field to query the range for, not null |
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372 * @return the range of valid values for the field, not null |
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373 * @throws DateTimeException if the range for the field cannot be obtained |
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374 */ |
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375 @Override |
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376 public ValueRange range(TemporalField field) { |
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377 if (field == YEAR_OF_ERA) { |
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378 return (year <= 0 ? ValueRange.of(1, MAX_VALUE + 1) : ValueRange.of(1, MAX_VALUE)); |
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379 } |
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380 return Temporal.super.range(field); |
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381 } |
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382 |
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383 /** |
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384 * Gets the value of the specified field from this year as an {@code int}. |
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385 * <p> |
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386 * This queries this year for the value for the specified field. |
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387 * The returned value will always be within the valid range of values for the field. |
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388 * If it is not possible to return the value, because the field is not supported |
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389 * or for some other reason, an exception is thrown. |
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390 * <p> |
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391 * If the field is a {@link ChronoField} then the query is implemented here. |
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392 * The {@link #isSupported(TemporalField) supported fields} will return valid |
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393 * values based on this year. |
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394 * All other {@code ChronoField} instances will throw a {@code DateTimeException}. |
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395 * <p> |
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396 * If the field is not a {@code ChronoField}, then the result of this method |
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397 * is obtained by invoking {@code TemporalField.doGet(TemporalAccessor)} |
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398 * passing {@code this} as the argument. Whether the value can be obtained, |
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399 * and what the value represents, is determined by the field. |
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400 * |
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401 * @param field the field to get, not null |
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402 * @return the value for the field |
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403 * @throws DateTimeException if a value for the field cannot be obtained |
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404 * @throws ArithmeticException if numeric overflow occurs |
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405 */ |
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406 @Override // override for Javadoc |
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407 public int get(TemporalField field) { |
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408 return range(field).checkValidIntValue(getLong(field), field); |
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409 } |
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410 |
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411 /** |
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412 * Gets the value of the specified field from this year as a {@code long}. |
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413 * <p> |
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414 * This queries this year for the value for the specified field. |
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415 * If it is not possible to return the value, because the field is not supported |
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416 * or for some other reason, an exception is thrown. |
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417 * <p> |
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418 * If the field is a {@link ChronoField} then the query is implemented here. |
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419 * The {@link #isSupported(TemporalField) supported fields} will return valid |
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420 * values based on this year. |
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421 * All other {@code ChronoField} instances will throw a {@code DateTimeException}. |
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422 * <p> |
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423 * If the field is not a {@code ChronoField}, then the result of this method |
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424 * is obtained by invoking {@code TemporalField.doGet(TemporalAccessor)} |
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425 * passing {@code this} as the argument. Whether the value can be obtained, |
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426 * and what the value represents, is determined by the field. |
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427 * |
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428 * @param field the field to get, not null |
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429 * @return the value for the field |
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430 * @throws DateTimeException if a value for the field cannot be obtained |
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431 * @throws ArithmeticException if numeric overflow occurs |
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432 */ |
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433 @Override |
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434 public long getLong(TemporalField field) { |
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435 if (field instanceof ChronoField) { |
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436 switch ((ChronoField) field) { |
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437 case YEAR_OF_ERA: return (year < 1 ? 1 - year : year); |
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438 case YEAR: return year; |
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439 case ERA: return (year < 1 ? 0 : 1); |
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440 } |
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441 throw new DateTimeException("Unsupported field: " + field.getName()); |
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442 } |
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443 return field.doGet(this); |
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444 } |
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445 |
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446 //----------------------------------------------------------------------- |
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447 /** |
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448 * Checks if the year is a leap year, according to the ISO proleptic |
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449 * calendar system rules. |
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450 * <p> |
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451 * This method applies the current rules for leap years across the whole time-line. |
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452 * In general, a year is a leap year if it is divisible by four without |
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453 * remainder. However, years divisible by 100, are not leap years, with |
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454 * the exception of years divisible by 400 which are. |
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455 * <p> |
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456 * For example, 1904 is a leap year it is divisible by 4. |
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457 * 1900 was not a leap year as it is divisible by 100, however 2000 was a |
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458 * leap year as it is divisible by 400. |
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459 * <p> |
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460 * The calculation is proleptic - applying the same rules into the far future and far past. |
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461 * This is historically inaccurate, but is correct for the ISO-8601 standard. |
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462 * |
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463 * @return true if the year is leap, false otherwise |
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464 */ |
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465 public boolean isLeap() { |
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466 return Year.isLeap(year); |
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467 } |
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468 |
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469 /** |
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470 * Checks if the month-day is valid for this year. |
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471 * <p> |
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472 * This method checks whether this year and the input month and day form |
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473 * a valid date. |
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474 * |
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475 * @param monthDay the month-day to validate, null returns false |
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476 * @return true if the month and day are valid for this year |
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477 */ |
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478 public boolean isValidMonthDay(MonthDay monthDay) { |
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479 return monthDay != null && monthDay.isValidYear(year); |
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480 } |
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481 |
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482 /** |
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483 * Gets the length of this year in days. |
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484 * |
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485 * @return the length of this year in days, 365 or 366 |
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486 */ |
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487 public int length() { |
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488 return isLeap() ? 366 : 365; |
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489 } |
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490 |
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491 //----------------------------------------------------------------------- |
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492 /** |
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493 * Returns an adjusted copy of this year. |
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494 * <p> |
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495 * This returns a new {@code Year}, based on this one, with the year adjusted. |
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496 * The adjustment takes place using the specified adjuster strategy object. |
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497 * Read the documentation of the adjuster to understand what adjustment will be made. |
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498 * <p> |
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499 * The result of this method is obtained by invoking the |
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500 * {@link TemporalAdjuster#adjustInto(Temporal)} method on the |
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501 * specified adjuster passing {@code this} as the argument. |
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502 * <p> |
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503 * This instance is immutable and unaffected by this method call. |
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504 * |
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505 * @param adjuster the adjuster to use, not null |
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506 * @return a {@code Year} based on {@code this} with the adjustment made, not null |
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507 * @throws DateTimeException if the adjustment cannot be made |
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508 * @throws ArithmeticException if numeric overflow occurs |
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509 */ |
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510 @Override |
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511 public Year with(TemporalAdjuster adjuster) { |
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512 return (Year) adjuster.adjustInto(this); |
|
513 } |
|
514 |
|
515 /** |
|
516 * Returns a copy of this year with the specified field set to a new value. |
|
517 * <p> |
|
518 * This returns a new {@code Year}, based on this one, with the value |
|
519 * for the specified field changed. |
|
520 * If it is not possible to set the value, because the field is not supported or for |
|
521 * some other reason, an exception is thrown. |
|
522 * <p> |
|
523 * If the field is a {@link ChronoField} then the adjustment is implemented here. |
|
524 * The supported fields behave as follows: |
|
525 * <ul> |
|
526 * <li>{@code YEAR_OF_ERA} - |
|
527 * Returns a {@code Year} with the specified year-of-era |
|
528 * The era will be unchanged. |
|
529 * <li>{@code YEAR} - |
|
530 * Returns a {@code Year} with the specified year. |
|
531 * This completely replaces the date and is equivalent to {@link #of(int)}. |
|
532 * <li>{@code ERA} - |
|
533 * Returns a {@code Year} with the specified era. |
|
534 * The year-of-era will be unchanged. |
|
535 * </ul> |
|
536 * <p> |
|
537 * In all cases, if the new value is outside the valid range of values for the field |
|
538 * then a {@code DateTimeException} will be thrown. |
|
539 * <p> |
|
540 * All other {@code ChronoField} instances will throw a {@code DateTimeException}. |
|
541 * <p> |
|
542 * If the field is not a {@code ChronoField}, then the result of this method |
|
543 * is obtained by invoking {@code TemporalField.doWith(Temporal, long)} |
|
544 * passing {@code this} as the argument. In this case, the field determines |
|
545 * whether and how to adjust the instant. |
|
546 * <p> |
|
547 * This instance is immutable and unaffected by this method call. |
|
548 * |
|
549 * @param field the field to set in the result, not null |
|
550 * @param newValue the new value of the field in the result |
|
551 * @return a {@code Year} based on {@code this} with the specified field set, not null |
|
552 * @throws DateTimeException if the field cannot be set |
|
553 * @throws ArithmeticException if numeric overflow occurs |
|
554 */ |
|
555 @Override |
|
556 public Year with(TemporalField field, long newValue) { |
|
557 if (field instanceof ChronoField) { |
|
558 ChronoField f = (ChronoField) field; |
|
559 f.checkValidValue(newValue); |
|
560 switch (f) { |
|
561 case YEAR_OF_ERA: return Year.of((int) (year < 1 ? 1 - newValue : newValue)); |
|
562 case YEAR: return Year.of((int) newValue); |
|
563 case ERA: return (getLong(ERA) == newValue ? this : Year.of(1 - year)); |
|
564 } |
|
565 throw new DateTimeException("Unsupported field: " + field.getName()); |
|
566 } |
|
567 return field.doWith(this, newValue); |
|
568 } |
|
569 |
|
570 //----------------------------------------------------------------------- |
|
571 /** |
|
572 * Returns a copy of this year with the specified period added. |
|
573 * <p> |
|
574 * This method returns a new year based on this year with the specified period added. |
|
575 * The adder is typically {@link java.time.Period} but may be any other type implementing |
|
576 * the {@link TemporalAdder} interface. |
|
577 * The calculation is delegated to the specified adjuster, which typically calls |
|
578 * back to {@link #plus(long, TemporalUnit)}. |
|
579 * <p> |
|
580 * This instance is immutable and unaffected by this method call. |
|
581 * |
|
582 * @param adder the adder to use, not null |
|
583 * @return a {@code Year} based on this year with the addition made, not null |
|
584 * @throws DateTimeException if the addition cannot be made |
|
585 * @throws ArithmeticException if numeric overflow occurs |
|
586 */ |
|
587 @Override |
|
588 public Year plus(TemporalAdder adder) { |
|
589 return (Year) adder.addTo(this); |
|
590 } |
|
591 |
|
592 /** |
|
593 * {@inheritDoc} |
|
594 * @throws DateTimeException {@inheritDoc} |
|
595 * @throws ArithmeticException {@inheritDoc} |
|
596 */ |
|
597 @Override |
|
598 public Year plus(long amountToAdd, TemporalUnit unit) { |
|
599 if (unit instanceof ChronoUnit) { |
|
600 switch ((ChronoUnit) unit) { |
|
601 case YEARS: return plusYears(amountToAdd); |
|
602 case DECADES: return plusYears(Math.multiplyExact(amountToAdd, 10)); |
|
603 case CENTURIES: return plusYears(Math.multiplyExact(amountToAdd, 100)); |
|
604 case MILLENNIA: return plusYears(Math.multiplyExact(amountToAdd, 1000)); |
|
605 case ERAS: return with(ERA, Math.addExact(getLong(ERA), amountToAdd)); |
|
606 } |
|
607 throw new DateTimeException("Unsupported unit: " + unit.getName()); |
|
608 } |
|
609 return unit.doPlus(this, amountToAdd); |
|
610 } |
|
611 |
|
612 /** |
|
613 * Returns a copy of this year with the specified number of years added. |
|
614 * <p> |
|
615 * This instance is immutable and unaffected by this method call. |
|
616 * |
|
617 * @param yearsToAdd the years to add, may be negative |
|
618 * @return a {@code Year} based on this year with the period added, not null |
|
619 * @throws DateTimeException if the result exceeds the supported year range |
|
620 */ |
|
621 public Year plusYears(long yearsToAdd) { |
|
622 if (yearsToAdd == 0) { |
|
623 return this; |
|
624 } |
|
625 return of(YEAR.checkValidIntValue(year + yearsToAdd)); // overflow safe |
|
626 } |
|
627 |
|
628 //----------------------------------------------------------------------- |
|
629 /** |
|
630 * Returns a copy of this year with the specified period subtracted. |
|
631 * <p> |
|
632 * This method returns a new year based on this year with the specified period subtracted. |
|
633 * The subtractor is typically {@link java.time.Period} but may be any other type implementing |
|
634 * the {@link TemporalSubtractor} interface. |
|
635 * The calculation is delegated to the specified adjuster, which typically calls |
|
636 * back to {@link #minus(long, TemporalUnit)}. |
|
637 * <p> |
|
638 * This instance is immutable and unaffected by this method call. |
|
639 * |
|
640 * @param subtractor the subtractor to use, not null |
|
641 * @return a {@code Year} based on this year with the subtraction made, not null |
|
642 * @throws DateTimeException if the subtraction cannot be made |
|
643 * @throws ArithmeticException if numeric overflow occurs |
|
644 */ |
|
645 @Override |
|
646 public Year minus(TemporalSubtractor subtractor) { |
|
647 return (Year) subtractor.subtractFrom(this); |
|
648 } |
|
649 |
|
650 /** |
|
651 * {@inheritDoc} |
|
652 * @throws DateTimeException {@inheritDoc} |
|
653 * @throws ArithmeticException {@inheritDoc} |
|
654 */ |
|
655 @Override |
|
656 public Year minus(long amountToSubtract, TemporalUnit unit) { |
|
657 return (amountToSubtract == Long.MIN_VALUE ? plus(Long.MAX_VALUE, unit).plus(1, unit) : plus(-amountToSubtract, unit)); |
|
658 } |
|
659 |
|
660 /** |
|
661 * Returns a copy of this year with the specified number of years subtracted. |
|
662 * <p> |
|
663 * This instance is immutable and unaffected by this method call. |
|
664 * |
|
665 * @param yearsToSubtract the years to subtract, may be negative |
|
666 * @return a {@code Year} based on this year with the period subtracted, not null |
|
667 * @throws DateTimeException if the result exceeds the supported year range |
|
668 */ |
|
669 public Year minusYears(long yearsToSubtract) { |
|
670 return (yearsToSubtract == Long.MIN_VALUE ? plusYears(Long.MAX_VALUE).plusYears(1) : plusYears(-yearsToSubtract)); |
|
671 } |
|
672 |
|
673 //----------------------------------------------------------------------- |
|
674 /** |
|
675 * Queries this year using the specified query. |
|
676 * <p> |
|
677 * This queries this year using the specified query strategy object. |
|
678 * The {@code TemporalQuery} object defines the logic to be used to |
|
679 * obtain the result. Read the documentation of the query to understand |
|
680 * what the result of this method will be. |
|
681 * <p> |
|
682 * The result of this method is obtained by invoking the |
|
683 * {@link TemporalQuery#queryFrom(TemporalAccessor)} method on the |
|
684 * specified query passing {@code this} as the argument. |
|
685 * |
|
686 * @param <R> the type of the result |
|
687 * @param query the query to invoke, not null |
|
688 * @return the query result, null may be returned (defined by the query) |
|
689 * @throws DateTimeException if unable to query (defined by the query) |
|
690 * @throws ArithmeticException if numeric overflow occurs (defined by the query) |
|
691 */ |
|
692 @SuppressWarnings("unchecked") |
|
693 @Override |
|
694 public <R> R query(TemporalQuery<R> query) { |
|
695 if (query == Queries.chrono()) { |
|
696 return (R) ISOChrono.INSTANCE; |
|
697 } else if (query == Queries.precision()) { |
|
698 return (R) YEARS; |
|
699 } |
|
700 return Temporal.super.query(query); |
|
701 } |
|
702 |
|
703 /** |
|
704 * Adjusts the specified temporal object to have this year. |
|
705 * <p> |
|
706 * This returns a temporal object of the same observable type as the input |
|
707 * with the year changed to be the same as this. |
|
708 * <p> |
|
709 * The adjustment is equivalent to using {@link Temporal#with(TemporalField, long)} |
|
710 * passing {@link ChronoField#YEAR} as the field. |
|
711 * If the specified temporal object does not use the ISO calendar system then |
|
712 * a {@code DateTimeException} is thrown. |
|
713 * <p> |
|
714 * In most cases, it is clearer to reverse the calling pattern by using |
|
715 * {@link Temporal#with(TemporalAdjuster)}: |
|
716 * <pre> |
|
717 * // these two lines are equivalent, but the second approach is recommended |
|
718 * temporal = thisYear.adjustInto(temporal); |
|
719 * temporal = temporal.with(thisYear); |
|
720 * </pre> |
|
721 * <p> |
|
722 * This instance is immutable and unaffected by this method call. |
|
723 * |
|
724 * @param temporal the target object to be adjusted, not null |
|
725 * @return the adjusted object, not null |
|
726 * @throws DateTimeException if unable to make the adjustment |
|
727 * @throws ArithmeticException if numeric overflow occurs |
|
728 */ |
|
729 @Override |
|
730 public Temporal adjustInto(Temporal temporal) { |
|
731 if (Chrono.from(temporal).equals(ISOChrono.INSTANCE) == false) { |
|
732 throw new DateTimeException("Adjustment only supported on ISO date-time"); |
|
733 } |
|
734 return temporal.with(YEAR, year); |
|
735 } |
|
736 |
|
737 /** |
|
738 * Calculates the period between this year and another year in |
|
739 * terms of the specified unit. |
|
740 * <p> |
|
741 * This calculates the period between two years in terms of a single unit. |
|
742 * The start and end points are {@code this} and the specified year. |
|
743 * The result will be negative if the end is before the start. |
|
744 * The {@code Temporal} passed to this method must be a {@code Year}. |
|
745 * For example, the period in decades between two year can be calculated |
|
746 * using {@code startYear.periodUntil(endYear, DECADES)}. |
|
747 * <p> |
|
748 * The calculation returns a whole number, representing the number of |
|
749 * complete units between the two years. |
|
750 * For example, the period in decades between 2012 and 2031 |
|
751 * will only be one decade as it is one year short of two decades. |
|
752 * <p> |
|
753 * This method operates in association with {@link TemporalUnit#between}. |
|
754 * The result of this method is a {@code long} representing the amount of |
|
755 * the specified unit. By contrast, the result of {@code between} is an |
|
756 * object that can be used directly in addition/subtraction: |
|
757 * <pre> |
|
758 * long period = start.periodUntil(end, YEARS); // this method |
|
759 * dateTime.plus(YEARS.between(start, end)); // use in plus/minus |
|
760 * </pre> |
|
761 * <p> |
|
762 * The calculation is implemented in this method for {@link ChronoUnit}. |
|
763 * The units {@code YEARS}, {@code DECADES}, {@code CENTURIES}, |
|
764 * {@code MILLENNIA} and {@code ERAS} are supported. |
|
765 * Other {@code ChronoUnit} values will throw an exception. |
|
766 * <p> |
|
767 * If the unit is not a {@code ChronoUnit}, then the result of this method |
|
768 * is obtained by invoking {@code TemporalUnit.between(Temporal, Temporal)} |
|
769 * passing {@code this} as the first argument and the input temporal as |
|
770 * the second argument. |
|
771 * <p> |
|
772 * This instance is immutable and unaffected by this method call. |
|
773 * |
|
774 * @param endYear the end year, which must be a {@code Year}, not null |
|
775 * @param unit the unit to measure the period in, not null |
|
776 * @return the amount of the period between this year and the end year |
|
777 * @throws DateTimeException if the period cannot be calculated |
|
778 * @throws ArithmeticException if numeric overflow occurs |
|
779 */ |
|
780 @Override |
|
781 public long periodUntil(Temporal endYear, TemporalUnit unit) { |
|
782 if (endYear instanceof Year == false) { |
|
783 Objects.requireNonNull(endYear, "endYear"); |
|
784 throw new DateTimeException("Unable to calculate period between objects of two different types"); |
|
785 } |
|
786 Year end = (Year) endYear; |
|
787 if (unit instanceof ChronoUnit) { |
|
788 long yearsUntil = ((long) end.year) - year; // no overflow |
|
789 switch ((ChronoUnit) unit) { |
|
790 case YEARS: return yearsUntil; |
|
791 case DECADES: return yearsUntil / 10; |
|
792 case CENTURIES: return yearsUntil / 100; |
|
793 case MILLENNIA: return yearsUntil / 1000; |
|
794 case ERAS: return end.getLong(ERA) - getLong(ERA); |
|
795 } |
|
796 throw new DateTimeException("Unsupported unit: " + unit.getName()); |
|
797 } |
|
798 return unit.between(this, endYear).getAmount(); |
|
799 } |
|
800 |
|
801 //----------------------------------------------------------------------- |
|
802 /** |
|
803 * Returns a date formed from this year at the specified day-of-year. |
|
804 * <p> |
|
805 * This combines this year and the specified day-of-year to form a {@code LocalDate}. |
|
806 * The day-of-year value 366 is only valid in a leap year. |
|
807 * <p> |
|
808 * This instance is immutable and unaffected by this method call. |
|
809 * |
|
810 * @param dayOfYear the day-of-year to use, not null |
|
811 * @return the local date formed from this year and the specified date of year, not null |
|
812 * @throws DateTimeException if the day of year is 366 and this is not a leap year |
|
813 */ |
|
814 public LocalDate atDay(int dayOfYear) { |
|
815 return LocalDate.ofYearDay(year, dayOfYear); |
|
816 } |
|
817 |
|
818 /** |
|
819 * Returns a year-month formed from this year at the specified month. |
|
820 * <p> |
|
821 * This combines this year and the specified month to form a {@code YearMonth}. |
|
822 * All possible combinations of year and month are valid. |
|
823 * <p> |
|
824 * This method can be used as part of a chain to produce a date: |
|
825 * <pre> |
|
826 * LocalDate date = year.atMonth(month).atDay(day); |
|
827 * </pre> |
|
828 * <p> |
|
829 * This instance is immutable and unaffected by this method call. |
|
830 * |
|
831 * @param month the month-of-year to use, not null |
|
832 * @return the year-month formed from this year and the specified month, not null |
|
833 */ |
|
834 public YearMonth atMonth(Month month) { |
|
835 return YearMonth.of(year, month); |
|
836 } |
|
837 |
|
838 /** |
|
839 * Returns a year-month formed from this year at the specified month. |
|
840 * <p> |
|
841 * This combines this year and the specified month to form a {@code YearMonth}. |
|
842 * All possible combinations of year and month are valid. |
|
843 * <p> |
|
844 * This method can be used as part of a chain to produce a date: |
|
845 * <pre> |
|
846 * LocalDate date = year.atMonth(month).atDay(day); |
|
847 * </pre> |
|
848 * <p> |
|
849 * This instance is immutable and unaffected by this method call. |
|
850 * |
|
851 * @param month the month-of-year to use, from 1 (January) to 12 (December) |
|
852 * @return the year-month formed from this year and the specified month, not null |
|
853 */ |
|
854 public YearMonth atMonth(int month) { |
|
855 return YearMonth.of(year, month); |
|
856 } |
|
857 |
|
858 /** |
|
859 * Returns a date formed from this year at the specified month-day. |
|
860 * <p> |
|
861 * This combines this year and the specified month-day to form a {@code LocalDate}. |
|
862 * The month-day value of February 29th is only valid in a leap year. |
|
863 * <p> |
|
864 * This instance is immutable and unaffected by this method call. |
|
865 * |
|
866 * @param monthDay the month-day to use, not null |
|
867 * @return the local date formed from this year and the specified month-day, not null |
|
868 * @throws DateTimeException if the month-day is February 29th and this is not a leap year |
|
869 */ |
|
870 public LocalDate atMonthDay(MonthDay monthDay) { |
|
871 return LocalDate.of(year, monthDay.getMonth(), monthDay.getDayOfMonth()); |
|
872 } |
|
873 |
|
874 //----------------------------------------------------------------------- |
|
875 /** |
|
876 * Compares this year to another year. |
|
877 * <p> |
|
878 * The comparison is based on the value of the year. |
|
879 * It is "consistent with equals", as defined by {@link Comparable}. |
|
880 * |
|
881 * @param other the other year to compare to, not null |
|
882 * @return the comparator value, negative if less, positive if greater |
|
883 */ |
|
884 public int compareTo(Year other) { |
|
885 return year - other.year; |
|
886 } |
|
887 |
|
888 /** |
|
889 * Is this year after the specified year. |
|
890 * |
|
891 * @param other the other year to compare to, not null |
|
892 * @return true if this is after the specified year |
|
893 */ |
|
894 public boolean isAfter(Year other) { |
|
895 return year > other.year; |
|
896 } |
|
897 |
|
898 /** |
|
899 * Is this year before the specified year. |
|
900 * |
|
901 * @param other the other year to compare to, not null |
|
902 * @return true if this point is before the specified year |
|
903 */ |
|
904 public boolean isBefore(Year other) { |
|
905 return year < other.year; |
|
906 } |
|
907 |
|
908 //----------------------------------------------------------------------- |
|
909 /** |
|
910 * Checks if this year is equal to another year. |
|
911 * <p> |
|
912 * The comparison is based on the time-line position of the years. |
|
913 * |
|
914 * @param obj the object to check, null returns false |
|
915 * @return true if this is equal to the other year |
|
916 */ |
|
917 @Override |
|
918 public boolean equals(Object obj) { |
|
919 if (this == obj) { |
|
920 return true; |
|
921 } |
|
922 if (obj instanceof Year) { |
|
923 return year == ((Year) obj).year; |
|
924 } |
|
925 return false; |
|
926 } |
|
927 |
|
928 /** |
|
929 * A hash code for this year. |
|
930 * |
|
931 * @return a suitable hash code |
|
932 */ |
|
933 @Override |
|
934 public int hashCode() { |
|
935 return year; |
|
936 } |
|
937 |
|
938 //----------------------------------------------------------------------- |
|
939 /** |
|
940 * Outputs this year as a {@code String}. |
|
941 * |
|
942 * @return a string representation of this year, not null |
|
943 */ |
|
944 @Override |
|
945 public String toString() { |
|
946 return Integer.toString(year); |
|
947 } |
|
948 |
|
949 /** |
|
950 * Outputs this year as a {@code String} using the formatter. |
|
951 * <p> |
|
952 * This year will be passed to the formatter |
|
953 * {@link DateTimeFormatter#print(TemporalAccessor) print method}. |
|
954 * |
|
955 * @param formatter the formatter to use, not null |
|
956 * @return the formatted year string, not null |
|
957 * @throws DateTimeException if an error occurs during printing |
|
958 */ |
|
959 public String toString(DateTimeFormatter formatter) { |
|
960 Objects.requireNonNull(formatter, "formatter"); |
|
961 return formatter.print(this); |
|
962 } |
|
963 |
|
964 //----------------------------------------------------------------------- |
|
965 /** |
|
966 * Writes the object using a |
|
967 * <a href="../../../serialized-form.html#java.time.temporal.Ser">dedicated serialized form</a>. |
|
968 * <pre> |
|
969 * out.writeByte(4); // identifies this as a Year |
|
970 * out.writeInt(year); |
|
971 * </pre> |
|
972 * |
|
973 * @return the instance of {@code Ser}, not null |
|
974 */ |
|
975 private Object writeReplace() { |
|
976 return new Ser(Ser.YEAR_TYPE, this); |
|
977 } |
|
978 |
|
979 /** |
|
980 * Defend against malicious streams. |
|
981 * @return never |
|
982 * @throws InvalidObjectException always |
|
983 */ |
|
984 private Object readResolve() throws ObjectStreamException { |
|
985 throw new InvalidObjectException("Deserialization via serialization delegate"); |
|
986 } |
|
987 |
|
988 void writeExternal(DataOutput out) throws IOException { |
|
989 out.writeInt(year); |
|
990 } |
|
991 |
|
992 static Year readExternal(DataInput in) throws IOException { |
|
993 return Year.of(in.readInt()); |
|
994 } |
|
995 |
|
996 } |
|