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.temporal; 63 64 import java.io.Serializable; 65 import java.time.Clock; 66 import java.time.DateTimeException; 67 import java.time.Instant; 68 import java.time.LocalDate; 69 import java.time.LocalDateTime; 70 import java.time.ZoneId; 71 import java.time.ZonedDateTime; 72 import java.util.Arrays; 73 import java.util.List; 74 import java.util.Locale; 75 import java.util.Objects; 76 77 /** 78 * The ISO calendar system. 79 * <p> 80 * This chronology defines the rules of the ISO calendar system. 81 * This calendar system is based on the ISO-8601 standard, which is the 82 * <i>de facto</i> world calendar. 83 * <p> 84 * The fields are defined as follows: 85 * <p><ul> 86 * <li>era - There are two eras, 'Current Era' (CE) and 'Before Current Era' (BCE). 87 * <li>year-of-era - The year-of-era is the same as the proleptic-year for the current CE era. 88 * For the BCE era before the ISO epoch the year increases from 1 upwards as time goes backwards. 89 * <li>proleptic-year - The proleptic year is the same as the year-of-era for the 90 * current era. For the previous era, years have zero, then negative values. 91 * <li>month-of-year - There are 12 months in an ISO year, numbered from 1 to 12. 92 * <li>day-of-month - There are between 28 and 31 days in each of the ISO month, numbered from 1 to 31. 93 * Months 4, 6, 9 and 11 have 30 days, Months 1, 3, 5, 7, 8, 10 and 12 have 31 days. 94 * Month 2 has 28 days, or 29 in a leap year. 95 * <li>day-of-year - There are 365 days in a standard ISO year and 366 in a leap year. 96 * The days are numbered from 1 to 365 or 1 to 366. 97 * <li>leap-year - Leap years occur every 4 years, except where the year is divisble by 100 and not divisble by 400. 98 * </ul><p> 99 * 100 * <h3>Specification for implementors</h3> 101 * This class is immutable and thread-safe. 102 * 103 * @since 1.8 104 */ 105 public final class ISOChrono extends Chrono<ISOChrono> implements Serializable { 106 107 /** 108 * Singleton instance of the ISO chronology. 109 */ 110 public static final ISOChrono INSTANCE = new ISOChrono(); 111 /** 112 * The singleton instance for the era BCE - 'Before Current Era'. 113 * The 'ISO' part of the name emphasizes that this differs from the BCE 114 * era in the Gregorian calendar system. 115 * This has the numeric value of {@code 0}. 116 */ 117 public static final Era<ISOChrono> ERA_BCE = ISOEra.BCE; 118 /** 119 * The singleton instance for the era CE - 'Current Era'. 120 * The 'ISO' part of the name emphasizes that this differs from the CE 121 * era in the Gregorian calendar system. 122 * This has the numeric value of {@code 1}. 123 */ 124 public static final Era<ISOChrono> ERA_CE = ISOEra.CE; 125 126 /** 127 * Serialization version. 128 */ 129 private static final long serialVersionUID = -1440403870442975015L; 130 131 /** 132 * Restricted constructor. 133 */ 134 private ISOChrono() { 135 } 136 137 /** 138 * Resolve singleton. 139 * 140 * @return the singleton instance, not null 141 */ 142 private Object readResolve() { 143 return INSTANCE; 144 } 145 146 //----------------------------------------------------------------------- 147 /** 148 * Gets the ID of the chronology - 'ISO'. 149 * <p> 150 * The ID uniquely identifies the {@code Chrono}. 151 * It can be used to lookup the {@code Chrono} using {@link #of(String)}. 152 * 153 * @return the chronology ID - 'ISO' 154 * @see #getCalendarType() 155 */ 156 @Override 157 public String getId() { 158 return "ISO"; 159 } 160 161 /** 162 * Gets the calendar type of the underlying calendar system - 'iso8601'. 163 * <p> 164 * The calendar type is an identifier defined by the 165 * <em>Unicode Locale Data Markup Language (LDML)</em> specification. 166 * It can be used to lookup the {@code Chrono} using {@link #of(String)}. 167 * It can also be used as part of a locale, accessible via 168 * {@link Locale#getUnicodeLocaleType(String)} with the key 'ca'. 169 * 170 * @return the calendar system type - 'iso8601' 171 * @see #getId() 172 */ 173 @Override 174 public String getCalendarType() { 175 return "iso8601"; 176 } 177 178 //----------------------------------------------------------------------- 179 /** 180 * Obtains an ISO local date from the era, year-of-era, month-of-year 181 * and day-of-month fields. 182 * 183 * @param era the ISO era, not null 184 * @param yearOfEra the ISO year-of-era 185 * @param month the ISO month-of-year 186 * @param dayOfMonth the ISO day-of-month 187 * @return the ISO local date, not null 188 * @throws DateTimeException if unable to create the date 189 */ 190 @Override // override with covariant return type 191 public LocalDate date(Era<ISOChrono> era, int yearOfEra, int month, int dayOfMonth) { 192 return date(prolepticYear(era, yearOfEra), month, dayOfMonth); 193 } 194 195 /** 196 * Obtains an ISO local date from the proleptic-year, month-of-year 197 * and day-of-month fields. 198 * <p> 199 * This is equivalent to {@link LocalDate#of(int, int, int)}. 200 * 201 * @param prolepticYear the ISO proleptic-year 202 * @param month the ISO month-of-year 203 * @param dayOfMonth the ISO day-of-month 204 * @return the ISO local date, not null 205 * @throws DateTimeException if unable to create the date 206 */ 207 @Override // override with covariant return type 208 public LocalDate date(int prolepticYear, int month, int dayOfMonth) { 209 return LocalDate.of(prolepticYear, month, dayOfMonth); 210 } 211 212 /** 213 * Obtains an ISO local date from the era, year-of-era and day-of-year fields. 214 * 215 * @param era the ISO era, not null 216 * @param yearOfEra the ISO year-of-era 217 * @param dayOfYear the ISO day-of-year 218 * @return the ISO local date, not null 219 * @throws DateTimeException if unable to create the date 220 */ 221 @Override // override with covariant return type 222 public LocalDate dateYearDay(Era<ISOChrono> era, int yearOfEra, int dayOfYear) { 223 return dateYearDay(prolepticYear(era, yearOfEra), dayOfYear); 224 } 225 226 /** 227 * Obtains an ISO local date from the proleptic-year and day-of-year fields. 228 * <p> 229 * This is equivalent to {@link LocalDate#ofYearDay(int, int)}. 230 * 231 * @param prolepticYear the ISO proleptic-year 232 * @param dayOfYear the ISO day-of-year 233 * @return the ISO local date, not null 234 * @throws DateTimeException if unable to create the date 235 */ 236 @Override // override with covariant return type 237 public LocalDate dateYearDay(int prolepticYear, int dayOfYear) { 238 return LocalDate.ofYearDay(prolepticYear, dayOfYear); 239 } 240 241 //----------------------------------------------------------------------- 242 /** 243 * Obtains an ISO local date from another date-time object. 244 * <p> 245 * This is equivalent to {@link LocalDate#from(TemporalAccessor)}. 246 * 247 * @param temporal the date-time object to convert, not null 248 * @return the ISO local date, not null 249 * @throws DateTimeException if unable to create the date 250 */ 251 @Override // override with covariant return type 252 public LocalDate date(TemporalAccessor temporal) { 253 return LocalDate.from(temporal); 254 } 255 256 /** 257 * Obtains an ISO local date-time from another date-time object. 258 * <p> 259 * This is equivalent to {@link LocalDateTime#from(TemporalAccessor)}. 260 * 261 * @param temporal the date-time object to convert, not null 262 * @return the ISO local date-time, not null 263 * @throws DateTimeException if unable to create the date-time 264 */ 265 @Override // override with covariant return type 266 public LocalDateTime localDateTime(TemporalAccessor temporal) { 267 return LocalDateTime.from(temporal); 268 } 269 270 /** 271 * Obtains an ISO zoned date-time from another date-time object. 272 * <p> 273 * This is equivalent to {@link ZonedDateTime#from(TemporalAccessor)}. 274 * 275 * @param temporal the date-time object to convert, not null 276 * @return the ISO zoned date-time, not null 277 * @throws DateTimeException if unable to create the date-time 278 */ 279 @Override // override with covariant return type 280 public ZonedDateTime zonedDateTime(TemporalAccessor temporal) { 281 return ZonedDateTime.from(temporal); 282 } 283 284 /** 285 * Obtains an ISO zoned date-time in this chronology from an {@code Instant}. 286 * <p> 287 * This is equivalent to {@link ZonedDateTime#ofInstant(Instant, ZoneId)}. 288 * 289 * @param instant the instant to create the date-time from, not null 290 * @param zone the time-zone, not null 291 * @return the zoned date-time, not null 292 * @throws DateTimeException if the result exceeds the supported range 293 */ 294 public ZonedDateTime zonedDateTime(Instant instant, ZoneId zone) { 295 return ZonedDateTime.ofInstant(instant, zone); 296 } 297 298 //----------------------------------------------------------------------- 299 /** 300 * Obtains the current ISO local date from the system clock in the default time-zone. 301 * <p> 302 * This will query the {@link Clock#systemDefaultZone() system clock} in the default 303 * time-zone to obtain the current date. 304 * <p> 305 * Using this method will prevent the ability to use an alternate clock for testing 306 * because the clock is hard-coded. 307 * 308 * @return the current ISO local date using the system clock and default time-zone, not null 309 * @throws DateTimeException if unable to create the date 310 */ 311 @Override // override with covariant return type 312 public LocalDate dateNow() { 313 return dateNow(Clock.systemDefaultZone()); 314 } 315 316 /** 317 * Obtains the current ISO local date from the system clock in the specified time-zone. 318 * <p> 319 * This will query the {@link Clock#system(ZoneId) system clock} to obtain the current date. 320 * Specifying the time-zone avoids dependence on the default time-zone. 321 * <p> 322 * Using this method will prevent the ability to use an alternate clock for testing 323 * because the clock is hard-coded. 324 * 325 * @return the current ISO local date using the system clock, not null 326 * @throws DateTimeException if unable to create the date 327 */ 328 @Override // override with covariant return type 329 public LocalDate dateNow(ZoneId zone) { 330 return dateNow(Clock.system(zone)); 331 } 332 333 /** 334 * Obtains the current ISO local date from the specified clock. 335 * <p> 336 * This will query the specified clock to obtain the current date - today. 337 * Using this method allows the use of an alternate clock for testing. 338 * The alternate clock may be introduced using {@link Clock dependency injection}. 339 * 340 * @param clock the clock to use, not null 341 * @return the current ISO local date, not null 342 * @throws DateTimeException if unable to create the date 343 */ 344 @Override // override with covariant return type 345 public LocalDate dateNow(Clock clock) { 346 Objects.requireNonNull(clock, "clock"); 347 return date(LocalDate.now(clock)); 348 } 349 350 //----------------------------------------------------------------------- 351 /** 352 * Checks if the year is a leap year, according to the ISO proleptic 353 * calendar system rules. 354 * <p> 355 * This method applies the current rules for leap years across the whole time-line. 356 * In general, a year is a leap year if it is divisible by four without 357 * remainder. However, years divisible by 100, are not leap years, with 358 * the exception of years divisible by 400 which are. 359 * <p> 360 * For example, 1904 is a leap year it is divisible by 4. 361 * 1900 was not a leap year as it is divisible by 100, however 2000 was a 362 * leap year as it is divisible by 400. 363 * <p> 364 * The calculation is proleptic - applying the same rules into the far future and far past. 365 * This is historically inaccurate, but is correct for the ISO-8601 standard. 366 * 367 * @param prolepticYear the ISO proleptic year to check 368 * @return true if the year is leap, false otherwise 369 */ 370 @Override 371 public boolean isLeapYear(long prolepticYear) { 372 return ((prolepticYear & 3) == 0) && ((prolepticYear % 100) != 0 || (prolepticYear % 400) == 0); 373 } 374 375 @Override 376 public int prolepticYear(Era<ISOChrono> era, int yearOfEra) { 377 if (era instanceof ISOEra == false) { 378 throw new DateTimeException("Era must be ISOEra"); 379 } 380 return (era == ISOEra.CE ? yearOfEra : 1 - yearOfEra); 381 } 382 383 @Override 384 public Era<ISOChrono> eraOf(int eraValue) { 385 return ISOEra.of(eraValue); 386 } 387 388 @Override 389 public List<Era<ISOChrono>> eras() { 390 return Arrays.<Era<ISOChrono>>asList(ISOEra.values()); 391 } 392 393 //----------------------------------------------------------------------- 394 @Override 395 public ValueRange range(ChronoField field) { 396 return field.range(); 397 } 398 399 }