1 /* 2 * Copyright (c) 2012, 2019, 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) 2007-2012, 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; 63 64 import java.io.DataOutput; 65 import java.io.IOException; 66 import java.io.InvalidObjectException; 67 import java.io.ObjectInputStream; 68 import java.io.Serializable; 69 import java.time.format.DateTimeFormatterBuilder; 70 import java.time.format.TextStyle; 71 import java.time.temporal.TemporalAccessor; 72 import java.time.temporal.TemporalField; 73 import java.time.temporal.TemporalQueries; 74 import java.time.temporal.TemporalQuery; 75 import java.time.temporal.UnsupportedTemporalTypeException; 76 import java.time.zone.ZoneRules; 77 import java.time.zone.ZoneRulesException; 78 import java.time.zone.ZoneRulesProvider; 79 import java.util.HashSet; 80 import java.util.Locale; 81 import java.util.Map; 82 import java.util.Objects; 83 import java.util.Set; 84 import java.util.TimeZone; 85 86 import static java.util.Map.entry; 87 88 // Android-changed: removed ValueBased paragraph. 89 // Android-changed: removed {@link ZoneRulesProvider}. 90 /** 91 * A time-zone ID, such as {@code Europe/Paris}. 92 * <p> 93 * A {@code ZoneId} is used to identify the rules used to convert between 94 * an {@link Instant} and a {@link LocalDateTime}. 95 * There are two distinct types of ID: 96 * <ul> 97 * <li>Fixed offsets - a fully resolved offset from UTC/Greenwich, that uses 98 * the same offset for all local date-times 99 * <li>Geographical regions - an area where a specific set of rules for finding 100 * the offset from UTC/Greenwich apply 101 * </ul> 102 * Most fixed offsets are represented by {@link ZoneOffset}. 103 * Calling {@link #normalized()} on any {@code ZoneId} will ensure that a 104 * fixed offset ID will be represented as a {@code ZoneOffset}. 105 * <p> 106 * The actual rules, describing when and how the offset changes, are defined by {@link ZoneRules}. 107 * This class is simply an ID used to obtain the underlying rules. 108 * This approach is taken because rules are defined by governments and change 109 * frequently, whereas the ID is stable. 110 * <p> 111 * The distinction has other effects. Serializing the {@code ZoneId} will only send 112 * the ID, whereas serializing the rules sends the entire data set. 113 * Similarly, a comparison of two IDs only examines the ID, whereas 114 * a comparison of two rules examines the entire data set. 115 * 116 * <h2>Time-zone IDs</h2> 117 * The ID is unique within the system. 118 * There are three types of ID. 119 * <p> 120 * The simplest type of ID is that from {@code ZoneOffset}. 121 * This consists of 'Z' and IDs starting with '+' or '-'. 122 * <p> 123 * The next type of ID are offset-style IDs with some form of prefix, 124 * such as 'GMT+2' or 'UTC+01:00'. 125 * The recognised prefixes are 'UTC', 'GMT' and 'UT'. 126 * The offset is the suffix and will be normalized during creation. 127 * These IDs can be normalized to a {@code ZoneOffset} using {@code normalized()}. 128 * <p> 129 * The third type of ID are region-based IDs. A region-based ID must be of 130 * two or more characters, and not start with 'UTC', 'GMT', 'UT' '+' or '-'. 131 * Region-based IDs are defined by configuration. 132 * The configuration focuses on providing the lookup from the ID to the 133 * underlying {@code ZoneRules}. 134 * <p> 135 * Time-zone rules are defined by governments and change frequently. 136 * There are a number of organizations, known here as groups, that monitor 137 * time-zone changes and collate them. 138 * The default group is the IANA Time Zone Database (TZDB). 139 * Other organizations include IATA (the airline industry body) and Microsoft. 140 * <p> 141 * Each group defines its own format for the region ID it provides. 142 * The TZDB group defines IDs such as 'Europe/London' or 'America/New_York'. 143 * TZDB IDs take precedence over other groups. 144 * <p> 145 * It is strongly recommended that the group name is included in all IDs supplied by 146 * groups other than TZDB to avoid conflicts. For example, IATA airline time-zone 147 * region IDs are typically the same as the three letter airport code. 148 * However, the airport of Utrecht has the code 'UTC', which is obviously a conflict. 149 * The recommended format for region IDs from groups other than TZDB is 'group~region'. 150 * Thus if IATA data were defined, Utrecht airport would be 'IATA~UTC'. 151 * 152 * <h2>Serialization</h2> 153 * This class can be serialized and stores the string zone ID in the external form. 154 * The {@code ZoneOffset} subclass uses a dedicated format that only stores the 155 * offset from UTC/Greenwich. 156 * <p> 157 * A {@code ZoneId} can be deserialized in a Java Runtime where the ID is unknown. 158 * For example, if a server-side Java Runtime has been updated with a new zone ID, but 159 * the client-side Java Runtime has not been updated. In this case, the {@code ZoneId} 160 * object will exist, and can be queried using {@code getId}, {@code equals}, 161 * {@code hashCode}, {@code toString}, {@code getDisplayName} and {@code normalized}. 162 * However, any call to {@code getRules} will fail with {@code ZoneRulesException}. 163 * This approach is designed to allow a {@link ZonedDateTime} to be loaded and 164 * queried, but not modified, on a Java Runtime with incomplete time-zone information. 165 * 166 * @implSpec 167 * This abstract class has two implementations, both of which are immutable and thread-safe. 168 * One implementation models region-based IDs, the other is {@code ZoneOffset} modelling 169 * offset-based IDs. This difference is visible in serialization. 170 * 171 * @since 1.8 172 */ 173 public abstract class ZoneId implements Serializable { 174 175 /** 176 * A map of zone overrides to enable the short time-zone names to be used. 177 * <p> 178 * Use of short zone IDs has been deprecated in {@code java.util.TimeZone}. 179 * This map allows the IDs to continue to be used via the 180 * {@link #of(String, Map)} factory method. 181 * <p> 182 * This map contains a mapping of the IDs that is in line with TZDB 2005r and 183 * later, where 'EST', 'MST' and 'HST' map to IDs which do not include daylight 184 * savings. 185 * <p> 186 * This maps as follows: 187 * <ul> 188 * <li>EST - -05:00</li> 189 * <li>HST - -10:00</li> 190 * <li>MST - -07:00</li> 191 * <li>ACT - Australia/Darwin</li> 192 * <li>AET - Australia/Sydney</li> 193 * <li>AGT - America/Argentina/Buenos_Aires</li> 194 * <li>ART - Africa/Cairo</li> 195 * <li>AST - America/Anchorage</li> 196 * <li>BET - America/Sao_Paulo</li> 197 * <li>BST - Asia/Dhaka</li> 198 * <li>CAT - Africa/Harare</li> 199 * <li>CNT - America/St_Johns</li> 200 * <li>CST - America/Chicago</li> 201 * <li>CTT - Asia/Shanghai</li> 202 * <li>EAT - Africa/Addis_Ababa</li> 203 * <li>ECT - Europe/Paris</li> 204 * <li>IET - America/Indiana/Indianapolis</li> 205 * <li>IST - Asia/Kolkata</li> 206 * <li>JST - Asia/Tokyo</li> 207 * <li>MIT - Pacific/Apia</li> 208 * <li>NET - Asia/Yerevan</li> 209 * <li>NST - Pacific/Auckland</li> 210 * <li>PLT - Asia/Karachi</li> 211 * <li>PNT - America/Phoenix</li> 212 * <li>PRT - America/Puerto_Rico</li> 213 * <li>PST - America/Los_Angeles</li> 214 * <li>SST - Pacific/Guadalcanal</li> 215 * <li>VST - Asia/Ho_Chi_Minh</li> 216 * </ul> 217 * The map is unmodifiable. 218 */ 219 public static final Map<String, String> SHORT_IDS = Map.ofEntries( 220 entry("ACT", "Australia/Darwin"), 221 entry("AET", "Australia/Sydney"), 222 entry("AGT", "America/Argentina/Buenos_Aires"), 223 entry("ART", "Africa/Cairo"), 224 entry("AST", "America/Anchorage"), 225 entry("BET", "America/Sao_Paulo"), 226 entry("BST", "Asia/Dhaka"), 227 entry("CAT", "Africa/Harare"), 228 entry("CNT", "America/St_Johns"), 229 entry("CST", "America/Chicago"), 230 entry("CTT", "Asia/Shanghai"), 231 entry("EAT", "Africa/Addis_Ababa"), 232 entry("ECT", "Europe/Paris"), 233 entry("IET", "America/Indiana/Indianapolis"), 234 entry("IST", "Asia/Kolkata"), 235 entry("JST", "Asia/Tokyo"), 236 entry("MIT", "Pacific/Apia"), 237 entry("NET", "Asia/Yerevan"), 238 entry("NST", "Pacific/Auckland"), 239 entry("PLT", "Asia/Karachi"), 240 entry("PNT", "America/Phoenix"), 241 entry("PRT", "America/Puerto_Rico"), 242 entry("PST", "America/Los_Angeles"), 243 entry("SST", "Pacific/Guadalcanal"), 244 entry("VST", "Asia/Ho_Chi_Minh"), 245 entry("EST", "-05:00"), 246 entry("MST", "-07:00"), 247 entry("HST", "-10:00") 248 ); 249 /** 250 * Serialization version. 251 */ 252 @java.io.Serial 253 private static final long serialVersionUID = 8352817235686L; 254 255 //----------------------------------------------------------------------- 256 /** 257 * Gets the system default time-zone. 258 * <p> 259 * This queries {@link TimeZone#getDefault()} to find the default time-zone 260 * and converts it to a {@code ZoneId}. If the system default time-zone is changed, 261 * then the result of this method will also change. 262 * 263 * @return the zone ID, not null 264 * @throws DateTimeException if the converted zone ID has an invalid format 265 * @throws ZoneRulesException if the converted zone region ID cannot be found 266 */ systemDefault()267 public static ZoneId systemDefault() { 268 return TimeZone.getDefault().toZoneId(); 269 } 270 271 /** 272 * Gets the set of available zone IDs. 273 * <p> 274 * This set includes the string form of all available region-based IDs. 275 * Offset-based zone IDs are not included in the returned set. 276 * The ID can be passed to {@link #of(String)} to create a {@code ZoneId}. 277 * <p> 278 * The set of zone IDs can increase over time, although in a typical application 279 * the set of IDs is fixed. Each call to this method is thread-safe. 280 * 281 * @return a modifiable copy of the set of zone IDs, not null 282 */ getAvailableZoneIds()283 public static Set<String> getAvailableZoneIds() { 284 return new HashSet<String>(ZoneRulesProvider.getAvailableZoneIds()); 285 } 286 287 //----------------------------------------------------------------------- 288 /** 289 * Obtains an instance of {@code ZoneId} using its ID using a map 290 * of aliases to supplement the standard zone IDs. 291 * <p> 292 * Many users of time-zones use short abbreviations, such as PST for 293 * 'Pacific Standard Time' and PDT for 'Pacific Daylight Time'. 294 * These abbreviations are not unique, and so cannot be used as IDs. 295 * This method allows a map of string to time-zone to be setup and reused 296 * within an application. 297 * 298 * @param zoneId the time-zone ID, not null 299 * @param aliasMap a map of alias zone IDs (typically abbreviations) to real zone IDs, not null 300 * @return the zone ID, not null 301 * @throws DateTimeException if the zone ID has an invalid format 302 * @throws ZoneRulesException if the zone ID is a region ID that cannot be found 303 */ of(String zoneId, Map<String, String> aliasMap)304 public static ZoneId of(String zoneId, Map<String, String> aliasMap) { 305 Objects.requireNonNull(zoneId, "zoneId"); 306 Objects.requireNonNull(aliasMap, "aliasMap"); 307 String id = Objects.requireNonNullElse(aliasMap.get(zoneId), zoneId); 308 return of(id); 309 } 310 311 /** 312 * Obtains an instance of {@code ZoneId} from an ID ensuring that the 313 * ID is valid and available for use. 314 * <p> 315 * This method parses the ID producing a {@code ZoneId} or {@code ZoneOffset}. 316 * A {@code ZoneOffset} is returned if the ID is 'Z', or starts with '+' or '-'. 317 * The result will always be a valid ID for which {@link ZoneRules} can be obtained. 318 * <p> 319 * Parsing matches the zone ID step by step as follows. 320 * <ul> 321 * <li>If the zone ID equals 'Z', the result is {@code ZoneOffset.UTC}. 322 * <li>If the zone ID consists of a single letter, the zone ID is invalid 323 * and {@code DateTimeException} is thrown. 324 * <li>If the zone ID starts with '+' or '-', the ID is parsed as a 325 * {@code ZoneOffset} using {@link ZoneOffset#of(String)}. 326 * <li>If the zone ID equals 'GMT', 'UTC' or 'UT' then the result is a {@code ZoneId} 327 * with the same ID and rules equivalent to {@code ZoneOffset.UTC}. 328 * <li>If the zone ID starts with 'UTC+', 'UTC-', 'GMT+', 'GMT-', 'UT+' or 'UT-' 329 * then the ID is a prefixed offset-based ID. The ID is split in two, with 330 * a two or three letter prefix and a suffix starting with the sign. 331 * The suffix is parsed as a {@link ZoneOffset#of(String) ZoneOffset}. 332 * The result will be a {@code ZoneId} with the specified UTC/GMT/UT prefix 333 * and the normalized offset ID as per {@link ZoneOffset#getId()}. 334 * The rules of the returned {@code ZoneId} will be equivalent to the 335 * parsed {@code ZoneOffset}. 336 * <li>All other IDs are parsed as region-based zone IDs. Region IDs must 337 * match the regular expression {@code [A-Za-z][A-Za-z0-9~/._+-]+} 338 * otherwise a {@code DateTimeException} is thrown. If the zone ID is not 339 * in the configured set of IDs, {@code ZoneRulesException} is thrown. 340 * The detailed format of the region ID depends on the group supplying the data. 341 * The default set of data is supplied by the IANA Time Zone Database (TZDB). 342 * This has region IDs of the form '{area}/{city}', such as 'Europe/Paris' or 'America/New_York'. 343 * This is compatible with most IDs from {@link java.util.TimeZone}. 344 * </ul> 345 * 346 * @param zoneId the time-zone ID, not null 347 * @return the zone ID, not null 348 * @throws DateTimeException if the zone ID has an invalid format 349 * @throws ZoneRulesException if the zone ID is a region ID that cannot be found 350 */ of(String zoneId)351 public static ZoneId of(String zoneId) { 352 return of(zoneId, true); 353 } 354 355 /** 356 * Obtains an instance of {@code ZoneId} wrapping an offset. 357 * <p> 358 * If the prefix is "GMT", "UTC", or "UT" a {@code ZoneId} 359 * with the prefix and the non-zero offset is returned. 360 * If the prefix is empty {@code ""} the {@code ZoneOffset} is returned. 361 * 362 * @param prefix the time-zone ID, not null 363 * @param offset the offset, not null 364 * @return the zone ID, not null 365 * @throws IllegalArgumentException if the prefix is not one of 366 * "GMT", "UTC", or "UT", or "" 367 */ ofOffset(String prefix, ZoneOffset offset)368 public static ZoneId ofOffset(String prefix, ZoneOffset offset) { 369 Objects.requireNonNull(prefix, "prefix"); 370 Objects.requireNonNull(offset, "offset"); 371 if (prefix.isEmpty()) { 372 return offset; 373 } 374 375 if (!prefix.equals("GMT") && !prefix.equals("UTC") && !prefix.equals("UT")) { 376 throw new IllegalArgumentException("prefix should be GMT, UTC or UT, is: " + prefix); 377 } 378 379 if (offset.getTotalSeconds() != 0) { 380 prefix = prefix.concat(offset.getId()); 381 } 382 return new ZoneRegion(prefix, offset.getRules()); 383 } 384 385 /** 386 * Parses the ID, taking a flag to indicate whether {@code ZoneRulesException} 387 * should be thrown or not, used in deserialization. 388 * 389 * @param zoneId the time-zone ID, not null 390 * @param checkAvailable whether to check if the zone ID is available 391 * @return the zone ID, not null 392 * @throws DateTimeException if the ID format is invalid 393 * @throws ZoneRulesException if checking availability and the ID cannot be found 394 */ of(String zoneId, boolean checkAvailable)395 static ZoneId of(String zoneId, boolean checkAvailable) { 396 Objects.requireNonNull(zoneId, "zoneId"); 397 if (zoneId.length() <= 1 || zoneId.startsWith("+") || zoneId.startsWith("-")) { 398 return ZoneOffset.of(zoneId); 399 } else if (zoneId.startsWith("UTC") || zoneId.startsWith("GMT")) { 400 return ofWithPrefix(zoneId, 3, checkAvailable); 401 } else if (zoneId.startsWith("UT")) { 402 return ofWithPrefix(zoneId, 2, checkAvailable); 403 } 404 return ZoneRegion.ofId(zoneId, checkAvailable); 405 } 406 407 /** 408 * Parse once a prefix is established. 409 * 410 * @param zoneId the time-zone ID, not null 411 * @param prefixLength the length of the prefix, 2 or 3 412 * @return the zone ID, not null 413 * @throws DateTimeException if the zone ID has an invalid format 414 */ ofWithPrefix(String zoneId, int prefixLength, boolean checkAvailable)415 private static ZoneId ofWithPrefix(String zoneId, int prefixLength, boolean checkAvailable) { 416 String prefix = zoneId.substring(0, prefixLength); 417 if (zoneId.length() == prefixLength) { 418 return ofOffset(prefix, ZoneOffset.UTC); 419 } 420 if (zoneId.charAt(prefixLength) != '+' && zoneId.charAt(prefixLength) != '-') { 421 return ZoneRegion.ofId(zoneId, checkAvailable); // drop through to ZoneRulesProvider 422 } 423 try { 424 ZoneOffset offset = ZoneOffset.of(zoneId.substring(prefixLength)); 425 if (offset == ZoneOffset.UTC) { 426 return ofOffset(prefix, offset); 427 } 428 return ofOffset(prefix, offset); 429 } catch (DateTimeException ex) { 430 throw new DateTimeException("Invalid ID for offset-based ZoneId: " + zoneId, ex); 431 } 432 } 433 434 //----------------------------------------------------------------------- 435 /** 436 * Obtains an instance of {@code ZoneId} from a temporal object. 437 * <p> 438 * This obtains a zone based on the specified temporal. 439 * A {@code TemporalAccessor} represents an arbitrary set of date and time information, 440 * which this factory converts to an instance of {@code ZoneId}. 441 * <p> 442 * A {@code TemporalAccessor} represents some form of date and time information. 443 * This factory converts the arbitrary temporal object to an instance of {@code ZoneId}. 444 * <p> 445 * The conversion will try to obtain the zone in a way that favours region-based 446 * zones over offset-based zones using {@link TemporalQueries#zone()}. 447 * <p> 448 * This method matches the signature of the functional interface {@link TemporalQuery} 449 * allowing it to be used as a query via method reference, {@code ZoneId::from}. 450 * 451 * @param temporal the temporal object to convert, not null 452 * @return the zone ID, not null 453 * @throws DateTimeException if unable to convert to a {@code ZoneId} 454 */ from(TemporalAccessor temporal)455 public static ZoneId from(TemporalAccessor temporal) { 456 ZoneId obj = temporal.query(TemporalQueries.zone()); 457 if (obj == null) { 458 throw new DateTimeException("Unable to obtain ZoneId from TemporalAccessor: " + 459 temporal + " of type " + temporal.getClass().getName()); 460 } 461 return obj; 462 } 463 464 //----------------------------------------------------------------------- 465 /** 466 * Constructor only accessible within the package. 467 */ ZoneId()468 ZoneId() { 469 if (getClass() != ZoneOffset.class && getClass() != ZoneRegion.class) { 470 throw new AssertionError("Invalid subclass"); 471 } 472 } 473 474 //----------------------------------------------------------------------- 475 /** 476 * Gets the unique time-zone ID. 477 * <p> 478 * This ID uniquely defines this object. 479 * The format of an offset based ID is defined by {@link ZoneOffset#getId()}. 480 * 481 * @return the time-zone unique ID, not null 482 */ getId()483 public abstract String getId(); 484 485 //----------------------------------------------------------------------- 486 /** 487 * Gets the textual representation of the zone, such as 'British Time' or 488 * '+02:00'. 489 * <p> 490 * This returns the textual name used to identify the time-zone ID, 491 * suitable for presentation to the user. 492 * The parameters control the style of the returned text and the locale. 493 * <p> 494 * If no textual mapping is found then the {@link #getId() full ID} is returned. 495 * 496 * @param style the length of the text required, not null 497 * @param locale the locale to use, not null 498 * @return the text value of the zone, not null 499 */ getDisplayName(TextStyle style, Locale locale)500 public String getDisplayName(TextStyle style, Locale locale) { 501 return new DateTimeFormatterBuilder().appendZoneText(style).toFormatter(locale).format(toTemporal()); 502 } 503 504 /** 505 * Converts this zone to a {@code TemporalAccessor}. 506 * <p> 507 * A {@code ZoneId} can be fully represented as a {@code TemporalAccessor}. 508 * However, the interface is not implemented by this class as most of the 509 * methods on the interface have no meaning to {@code ZoneId}. 510 * <p> 511 * The returned temporal has no supported fields, with the query method 512 * supporting the return of the zone using {@link TemporalQueries#zoneId()}. 513 * 514 * @return a temporal equivalent to this zone, not null 515 */ toTemporal()516 private TemporalAccessor toTemporal() { 517 return new TemporalAccessor() { 518 @Override 519 public boolean isSupported(TemporalField field) { 520 return false; 521 } 522 @Override 523 public long getLong(TemporalField field) { 524 throw new UnsupportedTemporalTypeException("Unsupported field: " + field); 525 } 526 @SuppressWarnings("unchecked") 527 @Override 528 public <R> R query(TemporalQuery<R> query) { 529 if (query == TemporalQueries.zoneId()) { 530 return (R) ZoneId.this; 531 } 532 return TemporalAccessor.super.query(query); 533 } 534 }; 535 } 536 537 //----------------------------------------------------------------------- 538 // Android-removed: ZoneRulesProvider related paragraph 539 /** 540 * Gets the time-zone rules for this ID allowing calculations to be performed. 541 * <p> 542 * The rules provide the functionality associated with a time-zone, 543 * such as finding the offset for a given instant or local date-time. 544 * <p> 545 * A time-zone can be invalid if it is deserialized in a Java Runtime which 546 * does not have the same rules loaded as the Java Runtime that stored it. 547 * In this case, calling this method will throw a {@code ZoneRulesException}. 548 * <p> 549 * {@link ZoneOffset} will always return a set of rules where the offset never changes. 550 * 551 * @return the rules, not null 552 * @throws ZoneRulesException if no rules are available for this ID 553 */ 554 public abstract ZoneRules getRules(); 555 556 /** 557 * Normalizes the time-zone ID, returning a {@code ZoneOffset} where possible. 558 * <p> 559 * The returns a normalized {@code ZoneId} that can be used in place of this ID. 560 * The result will have {@code ZoneRules} equivalent to those returned by this object, 561 * however the ID returned by {@code getId()} may be different. 562 * <p> 563 * The normalization checks if the rules of this {@code ZoneId} have a fixed offset. 564 * If they do, then the {@code ZoneOffset} equal to that offset is returned. 565 * Otherwise {@code this} is returned. 566 * 567 * @return the time-zone unique ID, not null 568 */ 569 public ZoneId normalized() { 570 try { 571 ZoneRules rules = getRules(); 572 if (rules.isFixedOffset()) { 573 return rules.getOffset(Instant.EPOCH); 574 } 575 } catch (ZoneRulesException ex) { 576 // invalid ZoneRegion is not important to this method 577 } 578 return this; 579 } 580 581 //----------------------------------------------------------------------- 582 /** 583 * Checks if this time-zone ID is equal to another time-zone ID. 584 * <p> 585 * The comparison is based on the ID. 586 * 587 * @param obj the object to check, null returns false 588 * @return true if this is equal to the other time-zone ID 589 */ 590 @Override 591 public boolean equals(Object obj) { 592 if (this == obj) { 593 return true; 594 } 595 return (obj instanceof ZoneId other) 596 && getId().equals(other.getId()); 597 } 598 599 /** 600 * A hash code for this time-zone ID. 601 * 602 * @return a suitable hash code 603 */ 604 @Override 605 public int hashCode() { 606 return getId().hashCode(); 607 } 608 609 //----------------------------------------------------------------------- 610 /** 611 * Defend against malicious streams. 612 * 613 * @param s the stream to read 614 * @throws InvalidObjectException always 615 */ 616 @java.io.Serial 617 private void readObject(ObjectInputStream s) throws InvalidObjectException { 618 throw new InvalidObjectException("Deserialization via serialization delegate"); 619 } 620 621 /** 622 * Outputs this zone as a {@code String}, using the ID. 623 * 624 * @return a string representation of this time-zone ID, not null 625 */ 626 @Override 627 public String toString() { 628 return getId(); 629 } 630 631 //----------------------------------------------------------------------- 632 /** 633 * Writes the object using a 634 * <a href="{@docRoot}/serialized-form.html#java.time.Ser">dedicated serialized form</a>. 635 * @serialData 636 * <pre> 637 * out.writeByte(7); // identifies a ZoneId (not ZoneOffset) 638 * out.writeUTF(getId()); 639 * </pre> 640 * <p> 641 * When read back in, the {@code ZoneId} will be created as though using 642 * {@link #of(String)}, but without any exception in the case where the 643 * ID has a valid format, but is not in the known set of region-based IDs. 644 * 645 * @return the instance of {@code Ser}, not null 646 */ 647 // this is here for serialization Javadoc 648 @java.io.Serial 649 private Object writeReplace() { 650 return new Ser(Ser.ZONE_REGION_TYPE, this); 651 } 652 653 abstract void write(DataOutput out) throws IOException; 654 655 } 656