1 /* 2 * Copyright (c) 2012, 2015, 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.Collections; 80 import java.util.HashMap; 81 import java.util.Locale; 82 import java.util.Map; 83 import java.util.Objects; 84 import java.util.Set; 85 import java.util.TimeZone; 86 87 // Android-changed: removed ValueBased paragraph. 88 // Android-changed: removed {@link ZoneRulesProvider}. 89 /** 90 * A time-zone ID, such as {@code Europe/Paris}. 91 * <p> 92 * A {@code ZoneId} is used to identify the rules used to convert between 93 * an {@link Instant} and a {@link LocalDateTime}. 94 * There are two distinct types of ID: 95 * <ul> 96 * <li>Fixed offsets - a fully resolved offset from UTC/Greenwich, that uses 97 * the same offset for all local date-times 98 * <li>Geographical regions - an area where a specific set of rules for finding 99 * the offset from UTC/Greenwich apply 100 * </ul> 101 * Most fixed offsets are represented by {@link ZoneOffset}. 102 * Calling {@link #normalized()} on any {@code ZoneId} will ensure that a 103 * fixed offset ID will be represented as a {@code ZoneOffset}. 104 * <p> 105 * The actual rules, describing when and how the offset changes, are defined by {@link ZoneRules}. 106 * This class is simply an ID used to obtain the underlying rules. 107 * This approach is taken because rules are defined by governments and change 108 * frequently, whereas the ID is stable. 109 * <p> 110 * The distinction has other effects. Serializing the {@code ZoneId} will only send 111 * the ID, whereas serializing the rules sends the entire data set. 112 * Similarly, a comparison of two IDs only examines the ID, whereas 113 * a comparison of two rules examines the entire data set. 114 * 115 * <h3>Time-zone IDs</h3> 116 * The ID is unique within the system. 117 * There are three types of ID. 118 * <p> 119 * The simplest type of ID is that from {@code ZoneOffset}. 120 * This consists of 'Z' and IDs starting with '+' or '-'. 121 * <p> 122 * The next type of ID are offset-style IDs with some form of prefix, 123 * such as 'GMT+2' or 'UTC+01:00'. 124 * The recognised prefixes are 'UTC', 'GMT' and 'UT'. 125 * The offset is the suffix and will be normalized during creation. 126 * These IDs can be normalized to a {@code ZoneOffset} using {@code normalized()}. 127 * <p> 128 * The third type of ID are region-based IDs. A region-based ID must be of 129 * two or more characters, and not start with 'UTC', 'GMT', 'UT' '+' or '-'. 130 * Region-based IDs are defined by configuration. 131 * The configuration focuses on providing the lookup from the ID to the 132 * underlying {@code ZoneRules}. 133 * <p> 134 * Time-zone rules are defined by governments and change frequently. 135 * There are a number of organizations, known here as groups, that monitor 136 * time-zone changes and collate them. 137 * The default group is the IANA Time Zone Database (TZDB). 138 * Other organizations include IATA (the airline industry body) and Microsoft. 139 * <p> 140 * Each group defines its own format for the region ID it provides. 141 * The TZDB group defines IDs such as 'Europe/London' or 'America/New_York'. 142 * TZDB IDs take precedence over other groups. 143 * <p> 144 * It is strongly recommended that the group name is included in all IDs supplied by 145 * groups other than TZDB to avoid conflicts. For example, IATA airline time-zone 146 * region IDs are typically the same as the three letter airport code. 147 * However, the airport of Utrecht has the code 'UTC', which is obviously a conflict. 148 * The recommended format for region IDs from groups other than TZDB is 'group~region'. 149 * Thus if IATA data were defined, Utrecht airport would be 'IATA~UTC'. 150 * 151 * <h3>Serialization</h3> 152 * This class can be serialized and stores the string zone ID in the external form. 153 * The {@code ZoneOffset} subclass uses a dedicated format that only stores the 154 * offset from UTC/Greenwich. 155 * <p> 156 * A {@code ZoneId} can be deserialized in a Java Runtime where the ID is unknown. 157 * For example, if a server-side Java Runtime has been updated with a new zone ID, but 158 * the client-side Java Runtime has not been updated. In this case, the {@code ZoneId} 159 * object will exist, and can be queried using {@code getId}, {@code equals}, 160 * {@code hashCode}, {@code toString}, {@code getDisplayName} and {@code normalized}. 161 * However, any call to {@code getRules} will fail with {@code ZoneRulesException}. 162 * This approach is designed to allow a {@link ZonedDateTime} to be loaded and 163 * queried, but not modified, on a Java Runtime with incomplete time-zone information. 164 * 165 * @implSpec 166 * This abstract class has two implementations, both of which are immutable and thread-safe. 167 * One implementation models region-based IDs, the other is {@code ZoneOffset} modelling 168 * offset-based IDs. This difference is visible in serialization. 169 * 170 * @since 1.8 171 */ 172 public abstract class ZoneId implements Serializable { 173 174 /** 175 * A map of zone overrides to enable the short time-zone names to be used. 176 * <p> 177 * Use of short zone IDs has been deprecated in {@code java.util.TimeZone}. 178 * This map allows the IDs to continue to be used via the 179 * {@link #of(String, Map)} factory method. 180 * <p> 181 * This map contains a mapping of the IDs that is in line with TZDB 2005r and 182 * later, where 'EST', 'MST' and 'HST' map to IDs which do not include daylight 183 * savings. 184 * <p> 185 * This maps as follows: 186 * <ul> 187 * <li>EST - -05:00</li> 188 * <li>HST - -10:00</li> 189 * <li>MST - -07:00</li> 190 * <li>ACT - Australia/Darwin</li> 191 * <li>AET - Australia/Sydney</li> 192 * <li>AGT - America/Argentina/Buenos_Aires</li> 193 * <li>ART - Africa/Cairo</li> 194 * <li>AST - America/Anchorage</li> 195 * <li>BET - America/Sao_Paulo</li> 196 * <li>BST - Asia/Dhaka</li> 197 * <li>CAT - Africa/Harare</li> 198 * <li>CNT - America/St_Johns</li> 199 * <li>CST - America/Chicago</li> 200 * <li>CTT - Asia/Shanghai</li> 201 * <li>EAT - Africa/Addis_Ababa</li> 202 * <li>ECT - Europe/Paris</li> 203 * <li>IET - America/Indiana/Indianapolis</li> 204 * <li>IST - Asia/Kolkata</li> 205 * <li>JST - Asia/Tokyo</li> 206 * <li>MIT - Pacific/Apia</li> 207 * <li>NET - Asia/Yerevan</li> 208 * <li>NST - Pacific/Auckland</li> 209 * <li>PLT - Asia/Karachi</li> 210 * <li>PNT - America/Phoenix</li> 211 * <li>PRT - America/Puerto_Rico</li> 212 * <li>PST - America/Los_Angeles</li> 213 * <li>SST - Pacific/Guadalcanal</li> 214 * <li>VST - Asia/Ho_Chi_Minh</li> 215 * </ul> 216 * The map is unmodifiable. 217 */ 218 public static final Map<String, String> SHORT_IDS; 219 static { 220 Map<String, String> map = new HashMap<>(64); 221 map.put("ACT", "Australia/Darwin"); 222 map.put("AET", "Australia/Sydney"); 223 map.put("AGT", "America/Argentina/Buenos_Aires"); 224 map.put("ART", "Africa/Cairo"); 225 map.put("AST", "America/Anchorage"); 226 map.put("BET", "America/Sao_Paulo"); 227 map.put("BST", "Asia/Dhaka"); 228 map.put("CAT", "Africa/Harare"); 229 map.put("CNT", "America/St_Johns"); 230 map.put("CST", "America/Chicago"); 231 map.put("CTT", "Asia/Shanghai"); 232 map.put("EAT", "Africa/Addis_Ababa"); 233 map.put("ECT", "Europe/Paris"); 234 map.put("IET", "America/Indiana/Indianapolis"); 235 map.put("IST", "Asia/Kolkata"); 236 map.put("JST", "Asia/Tokyo"); 237 map.put("MIT", "Pacific/Apia"); 238 map.put("NET", "Asia/Yerevan"); 239 map.put("NST", "Pacific/Auckland"); 240 map.put("PLT", "Asia/Karachi"); 241 map.put("PNT", "America/Phoenix"); 242 map.put("PRT", "America/Puerto_Rico"); 243 map.put("PST", "America/Los_Angeles"); 244 map.put("SST", "Pacific/Guadalcanal"); 245 map.put("VST", "Asia/Ho_Chi_Minh"); 246 map.put("EST", "-05:00"); 247 map.put("MST", "-07:00"); 248 map.put("HST", "-10:00"); 249 SHORT_IDS = Collections.unmodifiableMap(map); 250 } 251 /** 252 * Serialization version. 253 */ 254 private static final long serialVersionUID = 8352817235686L; 255 256 //----------------------------------------------------------------------- 257 /** 258 * Gets the system default time-zone. 259 * <p> 260 * This queries {@link TimeZone#getDefault()} to find the default time-zone 261 * and converts it to a {@code ZoneId}. If the system default time-zone is changed, 262 * then the result of this method will also change. 263 * 264 * @return the zone ID, not null 265 * @throws DateTimeException if the converted zone ID has an invalid format 266 * @throws ZoneRulesException if the converted zone region ID cannot be found 267 */ systemDefault()268 public static ZoneId systemDefault() { 269 return TimeZone.getDefault().toZoneId(); 270 } 271 272 /** 273 * Gets the set of available zone IDs. 274 * <p> 275 * This set includes the string form of all available region-based IDs. 276 * Offset-based zone IDs are not included in the returned set. 277 * The ID can be passed to {@link #of(String)} to create a {@code ZoneId}. 278 * <p> 279 * The set of zone IDs can increase over time, although in a typical application 280 * the set of IDs is fixed. Each call to this method is thread-safe. 281 * 282 * @return a modifiable copy of the set of zone IDs, not null 283 */ getAvailableZoneIds()284 public static Set<String> getAvailableZoneIds() { 285 return ZoneRulesProvider.getAvailableZoneIds(); 286 } 287 288 //----------------------------------------------------------------------- 289 /** 290 * Obtains an instance of {@code ZoneId} using its ID using a map 291 * of aliases to supplement the standard zone IDs. 292 * <p> 293 * Many users of time-zones use short abbreviations, such as PST for 294 * 'Pacific Standard Time' and PDT for 'Pacific Daylight Time'. 295 * These abbreviations are not unique, and so cannot be used as IDs. 296 * This method allows a map of string to time-zone to be setup and reused 297 * within an application. 298 * 299 * @param zoneId the time-zone ID, not null 300 * @param aliasMap a map of alias zone IDs (typically abbreviations) to real zone IDs, not null 301 * @return the zone ID, not null 302 * @throws DateTimeException if the zone ID has an invalid format 303 * @throws ZoneRulesException if the zone ID is a region ID that cannot be found 304 */ of(String zoneId, Map<String, String> aliasMap)305 public static ZoneId of(String zoneId, Map<String, String> aliasMap) { 306 Objects.requireNonNull(zoneId, "zoneId"); 307 Objects.requireNonNull(aliasMap, "aliasMap"); 308 String id = aliasMap.get(zoneId); 309 id = (id != null ? id : zoneId); 310 return of(id); 311 } 312 313 /** 314 * Obtains an instance of {@code ZoneId} from an ID ensuring that the 315 * ID is valid and available for use. 316 * <p> 317 * This method parses the ID producing a {@code ZoneId} or {@code ZoneOffset}. 318 * A {@code ZoneOffset} is returned if the ID is 'Z', or starts with '+' or '-'. 319 * The result will always be a valid ID for which {@link ZoneRules} can be obtained. 320 * <p> 321 * Parsing matches the zone ID step by step as follows. 322 * <ul> 323 * <li>If the zone ID equals 'Z', the result is {@code ZoneOffset.UTC}. 324 * <li>If the zone ID consists of a single letter, the zone ID is invalid 325 * and {@code DateTimeException} is thrown. 326 * <li>If the zone ID starts with '+' or '-', the ID is parsed as a 327 * {@code ZoneOffset} using {@link ZoneOffset#of(String)}. 328 * <li>If the zone ID equals 'GMT', 'UTC' or 'UT' then the result is a {@code ZoneId} 329 * with the same ID and rules equivalent to {@code ZoneOffset.UTC}. 330 * <li>If the zone ID starts with 'UTC+', 'UTC-', 'GMT+', 'GMT-', 'UT+' or 'UT-' 331 * then the ID is a prefixed offset-based ID. The ID is split in two, with 332 * a two or three letter prefix and a suffix starting with the sign. 333 * The suffix is parsed as a {@link ZoneOffset#of(String) ZoneOffset}. 334 * The result will be a {@code ZoneId} with the specified UTC/GMT/UT prefix 335 * and the normalized offset ID as per {@link ZoneOffset#getId()}. 336 * The rules of the returned {@code ZoneId} will be equivalent to the 337 * parsed {@code ZoneOffset}. 338 * <li>All other IDs are parsed as region-based zone IDs. Region IDs must 339 * match the regular expression <code>[A-Za-z][A-Za-z0-9~/._+-]+</code> 340 * otherwise a {@code DateTimeException} is thrown. If the zone ID is not 341 * in the configured set of IDs, {@code ZoneRulesException} is thrown. 342 * The detailed format of the region ID depends on the group supplying the data. 343 * The default set of data is supplied by the IANA Time Zone Database (TZDB). 344 * This has region IDs of the form '{area}/{city}', such as 'Europe/Paris' or 'America/New_York'. 345 * This is compatible with most IDs from {@link java.util.TimeZone}. 346 * </ul> 347 * 348 * @param zoneId the time-zone ID, not null 349 * @return the zone ID, not null 350 * @throws DateTimeException if the zone ID has an invalid format 351 * @throws ZoneRulesException if the zone ID is a region ID that cannot be found 352 */ of(String zoneId)353 public static ZoneId of(String zoneId) { 354 return of(zoneId, true); 355 } 356 357 /** 358 * Obtains an instance of {@code ZoneId} wrapping an offset. 359 * <p> 360 * If the prefix is "GMT", "UTC", or "UT" a {@code ZoneId} 361 * with the prefix and the non-zero offset is returned. 362 * If the prefix is empty {@code ""} the {@code ZoneOffset} is returned. 363 * 364 * @param prefix the time-zone ID, not null 365 * @param offset the offset, not null 366 * @return the zone ID, not null 367 * @throws IllegalArgumentException if the prefix is not one of 368 * "GMT", "UTC", or "UT", or "" 369 */ ofOffset(String prefix, ZoneOffset offset)370 public static ZoneId ofOffset(String prefix, ZoneOffset offset) { 371 Objects.requireNonNull(prefix, "prefix"); 372 Objects.requireNonNull(offset, "offset"); 373 if (prefix.length() == 0) { 374 return offset; 375 } 376 377 if (!prefix.equals("GMT") && !prefix.equals("UTC") && !prefix.equals("UT")) { 378 throw new IllegalArgumentException("prefix should be GMT, UTC or UT, is: " + prefix); 379 } 380 381 if (offset.getTotalSeconds() != 0) { 382 prefix = prefix.concat(offset.getId()); 383 } 384 return new ZoneRegion(prefix, offset.getRules()); 385 } 386 387 /** 388 * Parses the ID, taking a flag to indicate whether {@code ZoneRulesException} 389 * should be thrown or not, used in deserialization. 390 * 391 * @param zoneId the time-zone ID, not null 392 * @param checkAvailable whether to check if the zone ID is available 393 * @return the zone ID, not null 394 * @throws DateTimeException if the ID format is invalid 395 * @throws ZoneRulesException if checking availability and the ID cannot be found 396 */ of(String zoneId, boolean checkAvailable)397 static ZoneId of(String zoneId, boolean checkAvailable) { 398 Objects.requireNonNull(zoneId, "zoneId"); 399 if (zoneId.length() <= 1 || zoneId.startsWith("+") || zoneId.startsWith("-")) { 400 return ZoneOffset.of(zoneId); 401 } else if (zoneId.startsWith("UTC") || zoneId.startsWith("GMT")) { 402 return ofWithPrefix(zoneId, 3, checkAvailable); 403 } else if (zoneId.startsWith("UT")) { 404 return ofWithPrefix(zoneId, 2, checkAvailable); 405 } 406 return ZoneRegion.ofId(zoneId, checkAvailable); 407 } 408 409 /** 410 * Parse once a prefix is established. 411 * 412 * @param zoneId the time-zone ID, not null 413 * @param prefixLength the length of the prefix, 2 or 3 414 * @return the zone ID, not null 415 * @throws DateTimeException if the zone ID has an invalid format 416 */ ofWithPrefix(String zoneId, int prefixLength, boolean checkAvailable)417 private static ZoneId ofWithPrefix(String zoneId, int prefixLength, boolean checkAvailable) { 418 String prefix = zoneId.substring(0, prefixLength); 419 if (zoneId.length() == prefixLength) { 420 return ofOffset(prefix, ZoneOffset.UTC); 421 } 422 if (zoneId.charAt(prefixLength) != '+' && zoneId.charAt(prefixLength) != '-') { 423 return ZoneRegion.ofId(zoneId, checkAvailable); // drop through to ZoneRulesProvider 424 } 425 try { 426 ZoneOffset offset = ZoneOffset.of(zoneId.substring(prefixLength)); 427 if (offset == ZoneOffset.UTC) { 428 return ofOffset(prefix, offset); 429 } 430 return ofOffset(prefix, offset); 431 } catch (DateTimeException ex) { 432 throw new DateTimeException("Invalid ID for offset-based ZoneId: " + zoneId, ex); 433 } 434 } 435 436 //----------------------------------------------------------------------- 437 /** 438 * Obtains an instance of {@code ZoneId} from a temporal object. 439 * <p> 440 * This obtains a zone based on the specified temporal. 441 * A {@code TemporalAccessor} represents an arbitrary set of date and time information, 442 * which this factory converts to an instance of {@code ZoneId}. 443 * <p> 444 * A {@code TemporalAccessor} represents some form of date and time information. 445 * This factory converts the arbitrary temporal object to an instance of {@code ZoneId}. 446 * <p> 447 * The conversion will try to obtain the zone in a way that favours region-based 448 * zones over offset-based zones using {@link TemporalQueries#zone()}. 449 * <p> 450 * This method matches the signature of the functional interface {@link TemporalQuery} 451 * allowing it to be used as a query via method reference, {@code ZoneId::from}. 452 * 453 * @param temporal the temporal object to convert, not null 454 * @return the zone ID, not null 455 * @throws DateTimeException if unable to convert to a {@code ZoneId} 456 */ from(TemporalAccessor temporal)457 public static ZoneId from(TemporalAccessor temporal) { 458 ZoneId obj = temporal.query(TemporalQueries.zone()); 459 if (obj == null) { 460 throw new DateTimeException("Unable to obtain ZoneId from TemporalAccessor: " + 461 temporal + " of type " + temporal.getClass().getName()); 462 } 463 return obj; 464 } 465 466 //----------------------------------------------------------------------- 467 /** 468 * Constructor only accessible within the package. 469 */ ZoneId()470 ZoneId() { 471 if (getClass() != ZoneOffset.class && getClass() != ZoneRegion.class) { 472 throw new AssertionError("Invalid subclass"); 473 } 474 } 475 476 //----------------------------------------------------------------------- 477 /** 478 * Gets the unique time-zone ID. 479 * <p> 480 * This ID uniquely defines this object. 481 * The format of an offset based ID is defined by {@link ZoneOffset#getId()}. 482 * 483 * @return the time-zone unique ID, not null 484 */ getId()485 public abstract String getId(); 486 487 //----------------------------------------------------------------------- 488 /** 489 * Gets the textual representation of the zone, such as 'British Time' or 490 * '+02:00'. 491 * <p> 492 * This returns the textual name used to identify the time-zone ID, 493 * suitable for presentation to the user. 494 * The parameters control the style of the returned text and the locale. 495 * <p> 496 * If no textual mapping is found then the {@link #getId() full ID} is returned. 497 * 498 * @param style the length of the text required, not null 499 * @param locale the locale to use, not null 500 * @return the text value of the zone, not null 501 */ getDisplayName(TextStyle style, Locale locale)502 public String getDisplayName(TextStyle style, Locale locale) { 503 return new DateTimeFormatterBuilder().appendZoneText(style).toFormatter(locale).format(toTemporal()); 504 } 505 506 /** 507 * Converts this zone to a {@code TemporalAccessor}. 508 * <p> 509 * A {@code ZoneId} can be fully represented as a {@code TemporalAccessor}. 510 * However, the interface is not implemented by this class as most of the 511 * methods on the interface have no meaning to {@code ZoneId}. 512 * <p> 513 * The returned temporal has no supported fields, with the query method 514 * supporting the return of the zone using {@link TemporalQueries#zoneId()}. 515 * 516 * @return a temporal equivalent to this zone, not null 517 */ toTemporal()518 private TemporalAccessor toTemporal() { 519 return new TemporalAccessor() { 520 @Override 521 public boolean isSupported(TemporalField field) { 522 return false; 523 } 524 @Override 525 public long getLong(TemporalField field) { 526 throw new UnsupportedTemporalTypeException("Unsupported field: " + field); 527 } 528 @SuppressWarnings("unchecked") 529 @Override 530 public <R> R query(TemporalQuery<R> query) { 531 if (query == TemporalQueries.zoneId()) { 532 return (R) ZoneId.this; 533 } 534 return TemporalAccessor.super.query(query); 535 } 536 }; 537 } 538 539 //----------------------------------------------------------------------- 540 // Android-removed: ZoneRulesProvider related paragraph 541 /** 542 * Gets the time-zone rules for this ID allowing calculations to be performed. 543 * <p> 544 * The rules provide the functionality associated with a time-zone, 545 * such as finding the offset for a given instant or local date-time. 546 * <p> 547 * A time-zone can be invalid if it is deserialized in a Java Runtime which 548 * does not have the same rules loaded as the Java Runtime that stored it. 549 * In this case, calling this method will throw a {@code ZoneRulesException}. 550 * <p> 551 * {@link ZoneOffset} will always return a set of rules where the offset never changes. 552 * 553 * @return the rules, not null 554 * @throws ZoneRulesException if no rules are available for this ID 555 */ 556 public abstract ZoneRules getRules(); 557 558 /** 559 * Normalizes the time-zone ID, returning a {@code ZoneOffset} where possible. 560 * <p> 561 * The returns a normalized {@code ZoneId} that can be used in place of this ID. 562 * The result will have {@code ZoneRules} equivalent to those returned by this object, 563 * however the ID returned by {@code getId()} may be different. 564 * <p> 565 * The normalization checks if the rules of this {@code ZoneId} have a fixed offset. 566 * If they do, then the {@code ZoneOffset} equal to that offset is returned. 567 * Otherwise {@code this} is returned. 568 * 569 * @return the time-zone unique ID, not null 570 */ 571 public ZoneId normalized() { 572 try { 573 ZoneRules rules = getRules(); 574 if (rules.isFixedOffset()) { 575 return rules.getOffset(Instant.EPOCH); 576 } 577 } catch (ZoneRulesException ex) { 578 // invalid ZoneRegion is not important to this method 579 } 580 return this; 581 } 582 583 //----------------------------------------------------------------------- 584 /** 585 * Checks if this time-zone ID is equal to another time-zone ID. 586 * <p> 587 * The comparison is based on the ID. 588 * 589 * @param obj the object to check, null returns false 590 * @return true if this is equal to the other time-zone ID 591 */ 592 @Override 593 public boolean equals(Object obj) { 594 if (this == obj) { 595 return true; 596 } 597 if (obj instanceof ZoneId) { 598 ZoneId other = (ZoneId) obj; 599 return getId().equals(other.getId()); 600 } 601 return false; 602 } 603 604 /** 605 * A hash code for this time-zone ID. 606 * 607 * @return a suitable hash code 608 */ 609 @Override 610 public int hashCode() { 611 return getId().hashCode(); 612 } 613 614 //----------------------------------------------------------------------- 615 /** 616 * Defend against malicious streams. 617 * 618 * @param s the stream to read 619 * @throws InvalidObjectException always 620 */ 621 private void readObject(ObjectInputStream s) throws InvalidObjectException { 622 throw new InvalidObjectException("Deserialization via serialization delegate"); 623 } 624 625 /** 626 * Outputs this zone as a {@code String}, using the ID. 627 * 628 * @return a string representation of this time-zone ID, not null 629 */ 630 @Override 631 public String toString() { 632 return getId(); 633 } 634 635 //----------------------------------------------------------------------- 636 /** 637 * Writes the object using a 638 * <a href="../../serialized-form.html#java.time.Ser">dedicated serialized form</a>. 639 * @serialData 640 * <pre> 641 * out.writeByte(7); // identifies a ZoneId (not ZoneOffset) 642 * out.writeUTF(getId()); 643 * </pre> 644 * <p> 645 * When read back in, the {@code ZoneId} will be created as though using 646 * {@link #of(String)}, but without any exception in the case where the 647 * ID has a valid format, but is not in the known set of region-based IDs. 648 * 649 * @return the instance of {@code Ser}, not null 650 */ 651 // this is here for serialization Javadoc 652 private Object writeReplace() { 653 return new Ser(Ser.ZONE_REGION_TYPE, this); 654 } 655 656 abstract void write(DataOutput out) throws IOException; 657 658 } 659