1 /* 2 * Copyright (c) 2012, 2018, 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 * <h3>Time-zone IDs</h3> 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 * <h3>Serialization</h3> 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 private static final long serialVersionUID = 8352817235686L; 253 254 //----------------------------------------------------------------------- 255 /** 256 * Gets the system default time-zone. 257 * <p> 258 * This queries {@link TimeZone#getDefault()} to find the default time-zone 259 * and converts it to a {@code ZoneId}. If the system default time-zone is changed, 260 * then the result of this method will also change. 261 * 262 * @return the zone ID, not null 263 * @throws DateTimeException if the converted zone ID has an invalid format 264 * @throws ZoneRulesException if the converted zone region ID cannot be found 265 */ systemDefault()266 public static ZoneId systemDefault() { 267 return TimeZone.getDefault().toZoneId(); 268 } 269 270 /** 271 * Gets the set of available zone IDs. 272 * <p> 273 * This set includes the string form of all available region-based IDs. 274 * Offset-based zone IDs are not included in the returned set. 275 * The ID can be passed to {@link #of(String)} to create a {@code ZoneId}. 276 * <p> 277 * The set of zone IDs can increase over time, although in a typical application 278 * the set of IDs is fixed. Each call to this method is thread-safe. 279 * 280 * @return a modifiable copy of the set of zone IDs, not null 281 */ getAvailableZoneIds()282 public static Set<String> getAvailableZoneIds() { 283 return new HashSet<String>(ZoneRulesProvider.getAvailableZoneIds()); 284 } 285 286 //----------------------------------------------------------------------- 287 /** 288 * Obtains an instance of {@code ZoneId} using its ID using a map 289 * of aliases to supplement the standard zone IDs. 290 * <p> 291 * Many users of time-zones use short abbreviations, such as PST for 292 * 'Pacific Standard Time' and PDT for 'Pacific Daylight Time'. 293 * These abbreviations are not unique, and so cannot be used as IDs. 294 * This method allows a map of string to time-zone to be setup and reused 295 * within an application. 296 * 297 * @param zoneId the time-zone ID, not null 298 * @param aliasMap a map of alias zone IDs (typically abbreviations) to real zone IDs, not null 299 * @return the zone ID, not null 300 * @throws DateTimeException if the zone ID has an invalid format 301 * @throws ZoneRulesException if the zone ID is a region ID that cannot be found 302 */ of(String zoneId, Map<String, String> aliasMap)303 public static ZoneId of(String zoneId, Map<String, String> aliasMap) { 304 Objects.requireNonNull(zoneId, "zoneId"); 305 Objects.requireNonNull(aliasMap, "aliasMap"); 306 String id = Objects.requireNonNullElse(aliasMap.get(zoneId), zoneId); 307 return of(id); 308 } 309 310 /** 311 * Obtains an instance of {@code ZoneId} from an ID ensuring that the 312 * ID is valid and available for use. 313 * <p> 314 * This method parses the ID producing a {@code ZoneId} or {@code ZoneOffset}. 315 * A {@code ZoneOffset} is returned if the ID is 'Z', or starts with '+' or '-'. 316 * The result will always be a valid ID for which {@link ZoneRules} can be obtained. 317 * <p> 318 * Parsing matches the zone ID step by step as follows. 319 * <ul> 320 * <li>If the zone ID equals 'Z', the result is {@code ZoneOffset.UTC}. 321 * <li>If the zone ID consists of a single letter, the zone ID is invalid 322 * and {@code DateTimeException} is thrown. 323 * <li>If the zone ID starts with '+' or '-', the ID is parsed as a 324 * {@code ZoneOffset} using {@link ZoneOffset#of(String)}. 325 * <li>If the zone ID equals 'GMT', 'UTC' or 'UT' then the result is a {@code ZoneId} 326 * with the same ID and rules equivalent to {@code ZoneOffset.UTC}. 327 * <li>If the zone ID starts with 'UTC+', 'UTC-', 'GMT+', 'GMT-', 'UT+' or 'UT-' 328 * then the ID is a prefixed offset-based ID. The ID is split in two, with 329 * a two or three letter prefix and a suffix starting with the sign. 330 * The suffix is parsed as a {@link ZoneOffset#of(String) ZoneOffset}. 331 * The result will be a {@code ZoneId} with the specified UTC/GMT/UT prefix 332 * and the normalized offset ID as per {@link ZoneOffset#getId()}. 333 * The rules of the returned {@code ZoneId} will be equivalent to the 334 * parsed {@code ZoneOffset}. 335 * <li>All other IDs are parsed as region-based zone IDs. Region IDs must 336 * match the regular expression <code>[A-Za-z][A-Za-z0-9~/._+-]+</code> 337 * otherwise a {@code DateTimeException} is thrown. If the zone ID is not 338 * in the configured set of IDs, {@code ZoneRulesException} is thrown. 339 * The detailed format of the region ID depends on the group supplying the data. 340 * The default set of data is supplied by the IANA Time Zone Database (TZDB). 341 * This has region IDs of the form '{area}/{city}', such as 'Europe/Paris' or 'America/New_York'. 342 * This is compatible with most IDs from {@link java.util.TimeZone}. 343 * </ul> 344 * 345 * @param zoneId the time-zone ID, not null 346 * @return the zone ID, not null 347 * @throws DateTimeException if the zone ID has an invalid format 348 * @throws ZoneRulesException if the zone ID is a region ID that cannot be found 349 */ of(String zoneId)350 public static ZoneId of(String zoneId) { 351 return of(zoneId, true); 352 } 353 354 /** 355 * Obtains an instance of {@code ZoneId} wrapping an offset. 356 * <p> 357 * If the prefix is "GMT", "UTC", or "UT" a {@code ZoneId} 358 * with the prefix and the non-zero offset is returned. 359 * If the prefix is empty {@code ""} the {@code ZoneOffset} is returned. 360 * 361 * @param prefix the time-zone ID, not null 362 * @param offset the offset, not null 363 * @return the zone ID, not null 364 * @throws IllegalArgumentException if the prefix is not one of 365 * "GMT", "UTC", or "UT", or "" 366 */ ofOffset(String prefix, ZoneOffset offset)367 public static ZoneId ofOffset(String prefix, ZoneOffset offset) { 368 Objects.requireNonNull(prefix, "prefix"); 369 Objects.requireNonNull(offset, "offset"); 370 if (prefix.isEmpty()) { 371 return offset; 372 } 373 374 if (!prefix.equals("GMT") && !prefix.equals("UTC") && !prefix.equals("UT")) { 375 throw new IllegalArgumentException("prefix should be GMT, UTC or UT, is: " + prefix); 376 } 377 378 if (offset.getTotalSeconds() != 0) { 379 prefix = prefix.concat(offset.getId()); 380 } 381 return new ZoneRegion(prefix, offset.getRules()); 382 } 383 384 /** 385 * Parses the ID, taking a flag to indicate whether {@code ZoneRulesException} 386 * should be thrown or not, used in deserialization. 387 * 388 * @param zoneId the time-zone ID, not null 389 * @param checkAvailable whether to check if the zone ID is available 390 * @return the zone ID, not null 391 * @throws DateTimeException if the ID format is invalid 392 * @throws ZoneRulesException if checking availability and the ID cannot be found 393 */ of(String zoneId, boolean checkAvailable)394 static ZoneId of(String zoneId, boolean checkAvailable) { 395 Objects.requireNonNull(zoneId, "zoneId"); 396 if (zoneId.length() <= 1 || zoneId.startsWith("+") || zoneId.startsWith("-")) { 397 return ZoneOffset.of(zoneId); 398 } else if (zoneId.startsWith("UTC") || zoneId.startsWith("GMT")) { 399 return ofWithPrefix(zoneId, 3, checkAvailable); 400 } else if (zoneId.startsWith("UT")) { 401 return ofWithPrefix(zoneId, 2, checkAvailable); 402 } 403 return ZoneRegion.ofId(zoneId, checkAvailable); 404 } 405 406 /** 407 * Parse once a prefix is established. 408 * 409 * @param zoneId the time-zone ID, not null 410 * @param prefixLength the length of the prefix, 2 or 3 411 * @return the zone ID, not null 412 * @throws DateTimeException if the zone ID has an invalid format 413 */ ofWithPrefix(String zoneId, int prefixLength, boolean checkAvailable)414 private static ZoneId ofWithPrefix(String zoneId, int prefixLength, boolean checkAvailable) { 415 String prefix = zoneId.substring(0, prefixLength); 416 if (zoneId.length() == prefixLength) { 417 return ofOffset(prefix, ZoneOffset.UTC); 418 } 419 if (zoneId.charAt(prefixLength) != '+' && zoneId.charAt(prefixLength) != '-') { 420 return ZoneRegion.ofId(zoneId, checkAvailable); // drop through to ZoneRulesProvider 421 } 422 try { 423 ZoneOffset offset = ZoneOffset.of(zoneId.substring(prefixLength)); 424 if (offset == ZoneOffset.UTC) { 425 return ofOffset(prefix, offset); 426 } 427 return ofOffset(prefix, offset); 428 } catch (DateTimeException ex) { 429 throw new DateTimeException("Invalid ID for offset-based ZoneId: " + zoneId, ex); 430 } 431 } 432 433 //----------------------------------------------------------------------- 434 /** 435 * Obtains an instance of {@code ZoneId} from a temporal object. 436 * <p> 437 * This obtains a zone based on the specified temporal. 438 * A {@code TemporalAccessor} represents an arbitrary set of date and time information, 439 * which this factory converts to an instance of {@code ZoneId}. 440 * <p> 441 * A {@code TemporalAccessor} represents some form of date and time information. 442 * This factory converts the arbitrary temporal object to an instance of {@code ZoneId}. 443 * <p> 444 * The conversion will try to obtain the zone in a way that favours region-based 445 * zones over offset-based zones using {@link TemporalQueries#zone()}. 446 * <p> 447 * This method matches the signature of the functional interface {@link TemporalQuery} 448 * allowing it to be used as a query via method reference, {@code ZoneId::from}. 449 * 450 * @param temporal the temporal object to convert, not null 451 * @return the zone ID, not null 452 * @throws DateTimeException if unable to convert to a {@code ZoneId} 453 */ from(TemporalAccessor temporal)454 public static ZoneId from(TemporalAccessor temporal) { 455 ZoneId obj = temporal.query(TemporalQueries.zone()); 456 if (obj == null) { 457 throw new DateTimeException("Unable to obtain ZoneId from TemporalAccessor: " + 458 temporal + " of type " + temporal.getClass().getName()); 459 } 460 return obj; 461 } 462 463 //----------------------------------------------------------------------- 464 /** 465 * Constructor only accessible within the package. 466 */ ZoneId()467 ZoneId() { 468 if (getClass() != ZoneOffset.class && getClass() != ZoneRegion.class) { 469 throw new AssertionError("Invalid subclass"); 470 } 471 } 472 473 //----------------------------------------------------------------------- 474 /** 475 * Gets the unique time-zone ID. 476 * <p> 477 * This ID uniquely defines this object. 478 * The format of an offset based ID is defined by {@link ZoneOffset#getId()}. 479 * 480 * @return the time-zone unique ID, not null 481 */ getId()482 public abstract String getId(); 483 484 //----------------------------------------------------------------------- 485 /** 486 * Gets the textual representation of the zone, such as 'British Time' or 487 * '+02:00'. 488 * <p> 489 * This returns the textual name used to identify the time-zone ID, 490 * suitable for presentation to the user. 491 * The parameters control the style of the returned text and the locale. 492 * <p> 493 * If no textual mapping is found then the {@link #getId() full ID} is returned. 494 * 495 * @param style the length of the text required, not null 496 * @param locale the locale to use, not null 497 * @return the text value of the zone, not null 498 */ getDisplayName(TextStyle style, Locale locale)499 public String getDisplayName(TextStyle style, Locale locale) { 500 return new DateTimeFormatterBuilder().appendZoneText(style).toFormatter(locale).format(toTemporal()); 501 } 502 503 /** 504 * Converts this zone to a {@code TemporalAccessor}. 505 * <p> 506 * A {@code ZoneId} can be fully represented as a {@code TemporalAccessor}. 507 * However, the interface is not implemented by this class as most of the 508 * methods on the interface have no meaning to {@code ZoneId}. 509 * <p> 510 * The returned temporal has no supported fields, with the query method 511 * supporting the return of the zone using {@link TemporalQueries#zoneId()}. 512 * 513 * @return a temporal equivalent to this zone, not null 514 */ toTemporal()515 private TemporalAccessor toTemporal() { 516 return new TemporalAccessor() { 517 @Override 518 public boolean isSupported(TemporalField field) { 519 return false; 520 } 521 @Override 522 public long getLong(TemporalField field) { 523 throw new UnsupportedTemporalTypeException("Unsupported field: " + field); 524 } 525 @SuppressWarnings("unchecked") 526 @Override 527 public <R> R query(TemporalQuery<R> query) { 528 if (query == TemporalQueries.zoneId()) { 529 return (R) ZoneId.this; 530 } 531 return TemporalAccessor.super.query(query); 532 } 533 }; 534 } 535 536 //----------------------------------------------------------------------- 537 // Android-removed: ZoneRulesProvider related paragraph 538 /** 539 * Gets the time-zone rules for this ID allowing calculations to be performed. 540 * <p> 541 * The rules provide the functionality associated with a time-zone, 542 * such as finding the offset for a given instant or local date-time. 543 * <p> 544 * A time-zone can be invalid if it is deserialized in a Java Runtime which 545 * does not have the same rules loaded as the Java Runtime that stored it. 546 * In this case, calling this method will throw a {@code ZoneRulesException}. 547 * <p> 548 * {@link ZoneOffset} will always return a set of rules where the offset never changes. 549 * 550 * @return the rules, not null 551 * @throws ZoneRulesException if no rules are available for this ID 552 */ 553 public abstract ZoneRules getRules(); 554 555 /** 556 * Normalizes the time-zone ID, returning a {@code ZoneOffset} where possible. 557 * <p> 558 * The returns a normalized {@code ZoneId} that can be used in place of this ID. 559 * The result will have {@code ZoneRules} equivalent to those returned by this object, 560 * however the ID returned by {@code getId()} may be different. 561 * <p> 562 * The normalization checks if the rules of this {@code ZoneId} have a fixed offset. 563 * If they do, then the {@code ZoneOffset} equal to that offset is returned. 564 * Otherwise {@code this} is returned. 565 * 566 * @return the time-zone unique ID, not null 567 */ 568 public ZoneId normalized() { 569 try { 570 ZoneRules rules = getRules(); 571 if (rules.isFixedOffset()) { 572 return rules.getOffset(Instant.EPOCH); 573 } 574 } catch (ZoneRulesException ex) { 575 // invalid ZoneRegion is not important to this method 576 } 577 return this; 578 } 579 580 //----------------------------------------------------------------------- 581 /** 582 * Checks if this time-zone ID is equal to another time-zone ID. 583 * <p> 584 * The comparison is based on the ID. 585 * 586 * @param obj the object to check, null returns false 587 * @return true if this is equal to the other time-zone ID 588 */ 589 @Override 590 public boolean equals(Object obj) { 591 if (this == obj) { 592 return true; 593 } 594 if (obj instanceof ZoneId) { 595 ZoneId other = (ZoneId) obj; 596 return getId().equals(other.getId()); 597 } 598 return false; 599 } 600 601 /** 602 * A hash code for this time-zone ID. 603 * 604 * @return a suitable hash code 605 */ 606 @Override 607 public int hashCode() { 608 return getId().hashCode(); 609 } 610 611 //----------------------------------------------------------------------- 612 /** 613 * Defend against malicious streams. 614 * 615 * @param s the stream to read 616 * @throws InvalidObjectException always 617 */ 618 private void readObject(ObjectInputStream s) throws InvalidObjectException { 619 throw new InvalidObjectException("Deserialization via serialization delegate"); 620 } 621 622 /** 623 * Outputs this zone as a {@code String}, using the ID. 624 * 625 * @return a string representation of this time-zone ID, not null 626 */ 627 @Override 628 public String toString() { 629 return getId(); 630 } 631 632 //----------------------------------------------------------------------- 633 /** 634 * Writes the object using a 635 * <a href="../../serialized-form.html#java.time.Ser">dedicated serialized form</a>. 636 * @serialData 637 * <pre> 638 * out.writeByte(7); // identifies a ZoneId (not ZoneOffset) 639 * out.writeUTF(getId()); 640 * </pre> 641 * <p> 642 * When read back in, the {@code ZoneId} will be created as though using 643 * {@link #of(String)}, but without any exception in the case where the 644 * ID has a valid format, but is not in the known set of region-based IDs. 645 * 646 * @return the instance of {@code Ser}, not null 647 */ 648 // this is here for serialization Javadoc 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