1 /* 2 * Copyright (c) 1996, 2012, 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 * (C) Copyright Taligent, Inc. 1996 - All Rights Reserved 28 * (C) Copyright IBM Corp. 1996 - All Rights Reserved 29 * 30 * The original version of this source code and documentation is copyrighted 31 * and owned by Taligent, Inc., a wholly-owned subsidiary of IBM. These 32 * materials are provided under terms of a License Agreement between Taligent 33 * and Sun. This technology is protected by multiple US and International 34 * patents. This notice and attribution to Taligent may not be removed. 35 * Taligent is a registered trademark of Taligent, Inc. 36 * 37 */ 38 39 package java.util; 40 41 import java.io.Serializable; 42 import java.lang.ref.SoftReference; 43 import java.security.AccessController; 44 import java.security.PrivilegedAction; 45 import java.time.ZoneId; 46 import java.util.concurrent.ConcurrentHashMap; 47 import sun.misc.JavaAWTAccess; 48 import sun.misc.SharedSecrets; 49 import sun.security.action.GetPropertyAction; 50 import sun.util.calendar.ZoneInfo; 51 import sun.util.calendar.ZoneInfoFile; 52 import sun.util.locale.provider.TimeZoneNameUtility; 53 54 /** 55 * <code>TimeZone</code> represents a time zone offset, and also figures out daylight 56 * savings. 57 * 58 * <p> 59 * Typically, you get a <code>TimeZone</code> using <code>getDefault</code> 60 * which creates a <code>TimeZone</code> based on the time zone where the program 61 * is running. For example, for a program running in Japan, <code>getDefault</code> 62 * creates a <code>TimeZone</code> object based on Japanese Standard Time. 63 * 64 * <p> 65 * You can also get a <code>TimeZone</code> using <code>getTimeZone</code> 66 * along with a time zone ID. For instance, the time zone ID for the 67 * U.S. Pacific Time zone is "America/Los_Angeles". So, you can get a 68 * U.S. Pacific Time <code>TimeZone</code> object with: 69 * <blockquote><pre> 70 * TimeZone tz = TimeZone.getTimeZone("America/Los_Angeles"); 71 * </pre></blockquote> 72 * You can use the <code>getAvailableIDs</code> method to iterate through 73 * all the supported time zone IDs. You can then choose a 74 * supported ID to get a <code>TimeZone</code>. 75 * If the time zone you want is not represented by one of the 76 * supported IDs, then a custom time zone ID can be specified to 77 * produce a TimeZone. The syntax of a custom time zone ID is: 78 * 79 * <blockquote><pre> 80 * <a name="CustomID"><i>CustomID:</i></a> 81 * <code>GMT</code> <i>Sign</i> <i>Hours</i> <code>:</code> <i>Minutes</i> 82 * <code>GMT</code> <i>Sign</i> <i>Hours</i> <i>Minutes</i> 83 * <code>GMT</code> <i>Sign</i> <i>Hours</i> 84 * <i>Sign:</i> one of 85 * <code>+ -</code> 86 * <i>Hours:</i> 87 * <i>Digit</i> 88 * <i>Digit</i> <i>Digit</i> 89 * <i>Minutes:</i> 90 * <i>Digit</i> <i>Digit</i> 91 * <i>Digit:</i> one of 92 * <code>0 1 2 3 4 5 6 7 8 9</code> 93 * </pre></blockquote> 94 * 95 * <i>Hours</i> must be between 0 to 23 and <i>Minutes</i> must be 96 * between 00 to 59. For example, "GMT+10" and "GMT+0010" mean ten 97 * hours and ten minutes ahead of GMT, respectively. 98 * <p> 99 * The format is locale independent and digits must be taken from the 100 * Basic Latin block of the Unicode standard. No daylight saving time 101 * transition schedule can be specified with a custom time zone ID. If 102 * the specified string doesn't match the syntax, <code>"GMT"</code> 103 * is used. 104 * <p> 105 * When creating a <code>TimeZone</code>, the specified custom time 106 * zone ID is normalized in the following syntax: 107 * <blockquote><pre> 108 * <a name="NormalizedCustomID"><i>NormalizedCustomID:</i></a> 109 * <code>GMT</code> <i>Sign</i> <i>TwoDigitHours</i> <code>:</code> <i>Minutes</i> 110 * <i>Sign:</i> one of 111 * <code>+ -</code> 112 * <i>TwoDigitHours:</i> 113 * <i>Digit</i> <i>Digit</i> 114 * <i>Minutes:</i> 115 * <i>Digit</i> <i>Digit</i> 116 * <i>Digit:</i> one of 117 * <code>0 1 2 3 4 5 6 7 8 9</code> 118 * </pre></blockquote> 119 * For example, TimeZone.getTimeZone("GMT-8").getID() returns "GMT-08:00". 120 * 121 * <h4>Three-letter time zone IDs</h4> 122 * 123 * For compatibility with JDK 1.1.x, some other three-letter time zone IDs 124 * (such as "PST", "CTT", "AST") are also supported. However, <strong>their 125 * use is deprecated</strong> because the same abbreviation is often used 126 * for multiple time zones (for example, "CST" could be U.S. "Central Standard 127 * Time" and "China Standard Time"), and the Java platform can then only 128 * recognize one of them. 129 * 130 * 131 * @see Calendar 132 * @see GregorianCalendar 133 * @see SimpleTimeZone 134 * @author Mark Davis, David Goldsmith, Chen-Lieh Huang, Alan Liu 135 * @since JDK1.1 136 */ 137 abstract public class TimeZone implements Serializable, Cloneable { 138 /** 139 * Sole constructor. (For invocation by subclass constructors, typically 140 * implicit.) 141 */ 142 public TimeZone() { 143 } 144 145 /** 146 * A style specifier for <code>getDisplayName()</code> indicating 147 * a short name, such as "PST." 148 * @see #LONG 149 * @since 1.2 150 */ 151 public static final int SHORT = 0; 152 153 /** 154 * A style specifier for <code>getDisplayName()</code> indicating 155 * a long name, such as "Pacific Standard Time." 156 * @see #SHORT 157 * @since 1.2 158 */ 159 public static final int LONG = 1; 160 161 // Constants used internally; unit is milliseconds 162 private static final int ONE_MINUTE = 60*1000; 163 private static final int ONE_HOUR = 60*ONE_MINUTE; 164 private static final int ONE_DAY = 24*ONE_HOUR; 165 166 // Proclaim serialization compatibility with JDK 1.1 167 static final long serialVersionUID = 3581463369166924961L; 168 169 /** 170 * Gets the time zone offset, for current date, modified in case of 171 * daylight savings. This is the offset to add to UTC to get local time. 172 * <p> 173 * This method returns a historically correct offset if an 174 * underlying <code>TimeZone</code> implementation subclass 175 * supports historical Daylight Saving Time schedule and GMT 176 * offset changes. 177 * 178 * @param era the era of the given date. 179 * @param year the year in the given date. 180 * @param month the month in the given date. 181 * Month is 0-based. e.g., 0 for January. 182 * @param day the day-in-month of the given date. 183 * @param dayOfWeek the day-of-week of the given date. 184 * @param milliseconds the milliseconds in day in <em>standard</em> 185 * local time. 186 * 187 * @return the offset in milliseconds to add to GMT to get local time. 188 * 189 * @see Calendar#ZONE_OFFSET 190 * @see Calendar#DST_OFFSET 191 */ 192 public abstract int getOffset(int era, int year, int month, int day, 193 int dayOfWeek, int milliseconds); 194 195 /** 196 * Returns the offset of this time zone from UTC at the specified 197 * date. If Daylight Saving Time is in effect at the specified 198 * date, the offset value is adjusted with the amount of daylight 199 * saving. 200 * <p> 201 * This method returns a historically correct offset value if an 202 * underlying TimeZone implementation subclass supports historical 203 * Daylight Saving Time schedule and GMT offset changes. 204 * 205 * @param date the date represented in milliseconds since January 1, 1970 00:00:00 GMT 206 * @return the amount of time in milliseconds to add to UTC to get local time. 207 * 208 * @see Calendar#ZONE_OFFSET 209 * @see Calendar#DST_OFFSET 210 * @since 1.4 211 */ 212 public int getOffset(long date) { 213 if (inDaylightTime(new Date(date))) { 214 return getRawOffset() + getDSTSavings(); 215 } 216 return getRawOffset(); 217 } 218 219 /** 220 * Gets the raw GMT offset and the amount of daylight saving of this 221 * time zone at the given time. 222 * @param date the milliseconds (since January 1, 1970, 223 * 00:00:00.000 GMT) at which the time zone offset and daylight 224 * saving amount are found 225 * @param offsets an array of int where the raw GMT offset 226 * (offset[0]) and daylight saving amount (offset[1]) are stored, 227 * or null if those values are not needed. The method assumes that 228 * the length of the given array is two or larger. 229 * @return the total amount of the raw GMT offset and daylight 230 * saving at the specified date. 231 * 232 * @see Calendar#ZONE_OFFSET 233 * @see Calendar#DST_OFFSET 234 */ 235 int getOffsets(long date, int[] offsets) { 236 int rawoffset = getRawOffset(); 237 int dstoffset = 0; 238 if (inDaylightTime(new Date(date))) { 239 dstoffset = getDSTSavings(); 240 } 241 if (offsets != null) { 242 offsets[0] = rawoffset; 243 offsets[1] = dstoffset; 244 } 245 return rawoffset + dstoffset; 246 } 247 248 /** 249 * Sets the base time zone offset to GMT. 250 * This is the offset to add to UTC to get local time. 251 * <p> 252 * If an underlying <code>TimeZone</code> implementation subclass 253 * supports historical GMT offset changes, the specified GMT 254 * offset is set as the latest GMT offset and the difference from 255 * the known latest GMT offset value is used to adjust all 256 * historical GMT offset values. 257 * 258 * @param offsetMillis the given base time zone offset to GMT. 259 */ 260 abstract public void setRawOffset(int offsetMillis); 261 262 /** 263 * Returns the amount of time in milliseconds to add to UTC to get 264 * standard time in this time zone. Because this value is not 265 * affected by daylight saving time, it is called <I>raw 266 * offset</I>. 267 * <p> 268 * If an underlying <code>TimeZone</code> implementation subclass 269 * supports historical GMT offset changes, the method returns the 270 * raw offset value of the current date. In Honolulu, for example, 271 * its raw offset changed from GMT-10:30 to GMT-10:00 in 1947, and 272 * this method always returns -36000000 milliseconds (i.e., -10 273 * hours). 274 * 275 * @return the amount of raw offset time in milliseconds to add to UTC. 276 * @see Calendar#ZONE_OFFSET 277 */ 278 public abstract int getRawOffset(); 279 280 /** 281 * Gets the ID of this time zone. 282 * @return the ID of this time zone. 283 */ 284 public String getID() 285 { 286 return ID; 287 } 288 289 /** 290 * Sets the time zone ID. This does not change any other data in 291 * the time zone object. 292 * @param ID the new time zone ID. 293 */ 294 public void setID(String ID) 295 { 296 if (ID == null) { 297 throw new NullPointerException(); 298 } 299 this.ID = ID; 300 } 301 302 /** 303 * Returns a long standard time name of this {@code TimeZone} suitable for 304 * presentation to the user in the default locale. 305 * 306 * <p>This method is equivalent to: 307 * <pre><blockquote> 308 * getDisplayName(false, {@link #LONG}, 309 * Locale.getDefault({@link Locale.Category#DISPLAY})) 310 * </blockquote></pre> 311 * 312 * @return the human-readable name of this time zone in the default locale. 313 * @since 1.2 314 * @see #getDisplayName(boolean, int, Locale) 315 * @see Locale#getDefault(Locale.Category) 316 * @see Locale.Category 317 */ 318 public final String getDisplayName() { 319 return getDisplayName(false, LONG, 320 Locale.getDefault(Locale.Category.DISPLAY)); 321 } 322 323 /** 324 * Returns a long standard time name of this {@code TimeZone} suitable for 325 * presentation to the user in the specified {@code locale}. 326 * 327 * <p>This method is equivalent to: 328 * <pre><blockquote> 329 * getDisplayName(false, {@link #LONG}, locale) 330 * </blockquote></pre> 331 * 332 * @param locale the locale in which to supply the display name. 333 * @return the human-readable name of this time zone in the given locale. 334 * @exception NullPointerException if {@code locale} is {@code null}. 335 * @since 1.2 336 * @see #getDisplayName(boolean, int, Locale) 337 */ 338 public final String getDisplayName(Locale locale) { 339 return getDisplayName(false, LONG, locale); 340 } 341 342 /** 343 * Returns a name in the specified {@code style} of this {@code TimeZone} 344 * suitable for presentation to the user in the default locale. If the 345 * specified {@code daylight} is {@code true}, a Daylight Saving Time name 346 * is returned (even if this {@code TimeZone} doesn't observe Daylight Saving 347 * Time). Otherwise, a Standard Time name is returned. 348 * 349 * <p>This method is equivalent to: 350 * <pre><blockquote> 351 * getDisplayName(daylight, style, 352 * Locale.getDefault({@link Locale.Category#DISPLAY})) 353 * </blockquote></pre> 354 * 355 * @param daylight {@code true} specifying a Daylight Saving Time name, or 356 * {@code false} specifying a Standard Time name 357 * @param style either {@link #LONG} or {@link #SHORT} 358 * @return the human-readable name of this time zone in the default locale. 359 * @exception IllegalArgumentException if {@code style} is invalid. 360 * @since 1.2 361 * @see #getDisplayName(boolean, int, Locale) 362 * @see Locale#getDefault(Locale.Category) 363 * @see Locale.Category 364 * @see java.text.DateFormatSymbols#getZoneStrings() 365 */ 366 public final String getDisplayName(boolean daylight, int style) { 367 return getDisplayName(daylight, style, 368 Locale.getDefault(Locale.Category.DISPLAY)); 369 } 370 371 /** 372 * Returns a name in the specified {@code style} of this {@code TimeZone} 373 * suitable for presentation to the user in the specified {@code 374 * locale}. If the specified {@code daylight} is {@code true}, a Daylight 375 * Saving Time name is returned (even if this {@code TimeZone} doesn't 376 * observe Daylight Saving Time). Otherwise, a Standard Time name is 377 * returned. 378 * 379 * <p>When looking up a time zone name, the {@linkplain 380 * ResourceBundle.Control#getCandidateLocales(String,Locale) default 381 * <code>Locale</code> search path of <code>ResourceBundle</code>} derived 382 * from the specified {@code locale} is used. (No {@linkplain 383 * ResourceBundle.Control#getFallbackLocale(String,Locale) fallback 384 * <code>Locale</code>} search is performed.) If a time zone name in any 385 * {@code Locale} of the search path, including {@link Locale#ROOT}, is 386 * found, the name is returned. Otherwise, a string in the 387 * <a href="#NormalizedCustomID">normalized custom ID format</a> is returned. 388 * 389 * @param daylight {@code true} specifying a Daylight Saving Time name, or 390 * {@code false} specifying a Standard Time name 391 * @param style either {@link #LONG} or {@link #SHORT} 392 * @param locale the locale in which to supply the display name. 393 * @return the human-readable name of this time zone in the given locale. 394 * @exception IllegalArgumentException if {@code style} is invalid. 395 * @exception NullPointerException if {@code locale} is {@code null}. 396 * @since 1.2 397 * @see java.text.DateFormatSymbols#getZoneStrings() 398 */ 399 public String getDisplayName(boolean daylight, int style, Locale locale) { 400 if (style != SHORT && style != LONG) { 401 throw new IllegalArgumentException("Illegal style: " + style); 402 } 403 String id = getID(); 404 String name = TimeZoneNameUtility.retrieveDisplayName(id, daylight, style, locale); 405 if (name != null) { 406 return name; 407 } 408 409 if (id.startsWith("GMT") && id.length() > 3) { 410 char sign = id.charAt(3); 411 if (sign == '+' || sign == '-') { 412 return id; 413 } 414 } 415 int offset = getRawOffset(); 416 if (daylight) { 417 offset += getDSTSavings(); 418 } 419 return ZoneInfoFile.toCustomID(offset); 420 } 421 422 private static class DisplayNames { 423 // Cache for managing display names per timezone per locale 424 // The structure is: 425 // Map(key=id, value=SoftReference(Map(key=locale, value=displaynames))) 426 private static final Map<String, SoftReference<Map<Locale, String[]>>> CACHE = 427 new ConcurrentHashMap<>(); 428 429 private DisplayNames() { 430 } 431 } 432 433 private static String[] getDisplayNames(String id, Locale locale) { 434 return TimeZoneNameUtility.retrieveDisplayNames(id, locale); 435 } 436 437 /** 438 * Returns the amount of time to be added to local standard time 439 * to get local wall clock time. 440 * 441 * <p>The default implementation returns 3600000 milliseconds 442 * (i.e., one hour) if a call to {@link #useDaylightTime()} 443 * returns {@code true}. Otherwise, 0 (zero) is returned. 444 * 445 * <p>If an underlying {@code TimeZone} implementation subclass 446 * supports historical and future Daylight Saving Time schedule 447 * changes, this method returns the amount of saving time of the 448 * last known Daylight Saving Time rule that can be a future 449 * prediction. 450 * 451 * <p>If the amount of saving time at any given time stamp is 452 * required, construct a {@link Calendar} with this {@code 453 * TimeZone} and the time stamp, and call {@link Calendar#get(int) 454 * Calendar.get}{@code (}{@link Calendar#DST_OFFSET}{@code )}. 455 * 456 * @return the amount of saving time in milliseconds 457 * @since 1.4 458 * @see #inDaylightTime(Date) 459 * @see #getOffset(long) 460 * @see #getOffset(int,int,int,int,int,int) 461 * @see Calendar#ZONE_OFFSET 462 */ 463 public int getDSTSavings() { 464 if (useDaylightTime()) { 465 return 3600000; 466 } 467 return 0; 468 } 469 470 /** 471 * Queries if this {@code TimeZone} uses Daylight Saving Time. 472 * 473 * <p>If an underlying {@code TimeZone} implementation subclass 474 * supports historical and future Daylight Saving Time schedule 475 * changes, this method refers to the last known Daylight Saving Time 476 * rule that can be a future prediction and may not be the same as 477 * the current rule. Consider calling {@link #observesDaylightTime()} 478 * if the current rule should also be taken into account. 479 * 480 * @return {@code true} if this {@code TimeZone} uses Daylight Saving Time, 481 * {@code false}, otherwise. 482 * @see #inDaylightTime(Date) 483 * @see Calendar#DST_OFFSET 484 */ 485 public abstract boolean useDaylightTime(); 486 487 /** 488 * Returns {@code true} if this {@code TimeZone} is currently in 489 * Daylight Saving Time, or if a transition from Standard Time to 490 * Daylight Saving Time occurs at any future time. 491 * 492 * <p>The default implementation returns {@code true} if 493 * {@code useDaylightTime()} or {@code inDaylightTime(new Date())} 494 * returns {@code true}. 495 * 496 * @return {@code true} if this {@code TimeZone} is currently in 497 * Daylight Saving Time, or if a transition from Standard Time to 498 * Daylight Saving Time occurs at any future time; {@code false} 499 * otherwise. 500 * @since 1.7 501 * @see #useDaylightTime() 502 * @see #inDaylightTime(Date) 503 * @see Calendar#DST_OFFSET 504 */ 505 public boolean observesDaylightTime() { 506 return useDaylightTime() || inDaylightTime(new Date()); 507 } 508 509 /** 510 * Queries if the given {@code date} is in Daylight Saving Time in 511 * this time zone. 512 * 513 * @param date the given Date. 514 * @return {@code true} if the given date is in Daylight Saving Time, 515 * {@code false}, otherwise. 516 */ 517 abstract public boolean inDaylightTime(Date date); 518 519 /** 520 * Gets the <code>TimeZone</code> for the given ID. 521 * 522 * @param ID the ID for a <code>TimeZone</code>, either an abbreviation 523 * such as "PST", a full name such as "America/Los_Angeles", or a custom 524 * ID such as "GMT-8:00". Note that the support of abbreviations is 525 * for JDK 1.1.x compatibility only and full names should be used. 526 * 527 * @return the specified <code>TimeZone</code>, or the GMT zone if the given ID 528 * cannot be understood. 529 */ 530 public static synchronized TimeZone getTimeZone(String ID) { 531 return getTimeZone(ID, true); 532 } 533 534 /** 535 * Gets the {@code TimeZone} for the given {@code zoneId}. 536 * 537 * @param zoneId a {@link ZoneId} from which the time zone ID is obtained 538 * @return the specified {@code TimeZone}, or the GMT zone if the given ID 539 * cannot be understood. 540 * @throws NullPointerException if {@code zoneId} is {@code null} 541 * @since 1.8 542 */ 543 public static TimeZone getTimeZone(ZoneId zoneId) { 544 String tzid = zoneId.getId(); // throws an NPE if null 545 char c = tzid.charAt(0); 546 if (c == '+' || c == '-') { 547 tzid = "GMT" + tzid; 548 } else if (c == 'Z' && tzid.length() == 1) { 549 tzid = "UTC"; 550 } 551 return getTimeZone(tzid, true); 552 } 553 554 /** 555 * Converts this {@code TimeZone} object to a {@code ZoneId}. 556 * 557 * @return a {@code ZoneId} representing the same time zone as this 558 * {@code TimeZone} 559 * @since 1.8 560 */ 561 public ZoneId toZoneId() { 562 return ZoneId.of(getID(), ZoneId.OLD_IDS_POST_2005); 563 } 564 565 private static TimeZone getTimeZone(String ID, boolean fallback) { 566 TimeZone tz = ZoneInfo.getTimeZone(ID); 567 if (tz == null) { 568 tz = parseCustomTimeZone(ID); 569 if (tz == null && fallback) { 570 tz = new ZoneInfo(GMT_ID, 0); 571 } 572 } 573 return tz; 574 } 575 576 /** 577 * Gets the available IDs according to the given time zone offset in milliseconds. 578 * 579 * @param rawOffset the given time zone GMT offset in milliseconds. 580 * @return an array of IDs, where the time zone for that ID has 581 * the specified GMT offset. For example, "America/Phoenix" and "America/Denver" 582 * both have GMT-07:00, but differ in daylight saving behavior. 583 * @see #getRawOffset() 584 */ 585 public static synchronized String[] getAvailableIDs(int rawOffset) { 586 return ZoneInfo.getAvailableIDs(rawOffset); 587 } 588 589 /** 590 * Gets all the available IDs supported. 591 * @return an array of IDs. 592 */ 593 public static synchronized String[] getAvailableIDs() { 594 return ZoneInfo.getAvailableIDs(); 595 } 596 597 /** 598 * Gets the platform defined TimeZone ID. 599 **/ 600 private static native String getSystemTimeZoneID(String javaHome, 601 String country); 602 603 /** 604 * Gets the custom time zone ID based on the GMT offset of the 605 * platform. (e.g., "GMT+08:00") 606 */ 607 private static native String getSystemGMTOffsetID(); 608 609 /** 610 * Gets the default <code>TimeZone</code> for this host. 611 * The source of the default <code>TimeZone</code> 612 * may vary with implementation. 613 * @return a default <code>TimeZone</code>. 614 * @see #setDefault 615 */ 616 public static TimeZone getDefault() { 617 return (TimeZone) getDefaultRef().clone(); 618 } 619 620 /** 621 * Returns the reference to the default TimeZone object. This 622 * method doesn't create a clone. 623 */ 624 static TimeZone getDefaultRef() { 625 TimeZone defaultZone = getDefaultInAppContext(); 626 if (defaultZone == null) { 627 defaultZone = defaultTimeZone; 628 if (defaultZone == null) { 629 // Need to initialize the default time zone. 630 defaultZone = setDefaultZone(); 631 assert defaultZone != null; 632 } 633 } 634 // Don't clone here. 635 return defaultZone; 636 } 637 638 private static synchronized TimeZone setDefaultZone() { 639 TimeZone tz; 640 // get the time zone ID from the system properties 641 String zoneID = AccessController.doPrivileged( 642 new GetPropertyAction("user.timezone")); 643 644 // if the time zone ID is not set (yet), perform the 645 // platform to Java time zone ID mapping. 646 if (zoneID == null || zoneID.isEmpty()) { 647 String country = AccessController.doPrivileged( 648 new GetPropertyAction("user.country")); 649 String javaHome = AccessController.doPrivileged( 650 new GetPropertyAction("java.home")); 651 try { 652 zoneID = getSystemTimeZoneID(javaHome, country); 653 if (zoneID == null) { 654 zoneID = GMT_ID; 655 } 656 } catch (NullPointerException e) { 657 zoneID = GMT_ID; 658 } 659 } 660 661 // Get the time zone for zoneID. But not fall back to 662 // "GMT" here. 663 tz = getTimeZone(zoneID, false); 664 665 if (tz == null) { 666 // If the given zone ID is unknown in Java, try to 667 // get the GMT-offset-based time zone ID, 668 // a.k.a. custom time zone ID (e.g., "GMT-08:00"). 669 String gmtOffsetID = getSystemGMTOffsetID(); 670 if (gmtOffsetID != null) { 671 zoneID = gmtOffsetID; 672 } 673 tz = getTimeZone(zoneID, true); 674 } 675 assert tz != null; 676 677 final String id = zoneID; 678 AccessController.doPrivileged(new PrivilegedAction<Void>() { 679 @Override 680 public Void run() { 681 System.setProperty("user.timezone", id); 682 return null; 683 } 684 }); 685 686 defaultTimeZone = tz; 687 return tz; 688 } 689 690 private static boolean hasPermission() { 691 boolean hasPermission = true; 692 SecurityManager sm = System.getSecurityManager(); 693 if (sm != null) { 694 try { 695 sm.checkPermission(new PropertyPermission 696 ("user.timezone", "write")); 697 } catch (SecurityException e) { 698 hasPermission = false; 699 } 700 } 701 return hasPermission; 702 } 703 704 /** 705 * Sets the <code>TimeZone</code> that is 706 * returned by the <code>getDefault</code> method. If <code>zone</code> 707 * is null, reset the default to the value it had originally when the 708 * VM first started. 709 * @param zone the new default time zone 710 * @see #getDefault 711 */ 712 public static void setDefault(TimeZone zone) 713 { 714 if (hasPermission()) { 715 synchronized (TimeZone.class) { 716 defaultTimeZone = zone; 717 setDefaultInAppContext(null); 718 } 719 } else { 720 setDefaultInAppContext(zone); 721 } 722 } 723 724 /** 725 * Returns the default TimeZone in an AppContext if any AppContext 726 * has ever used. null is returned if any AppContext hasn't been 727 * used or if the AppContext doesn't have the default TimeZone. 728 * 729 * Note that javaAWTAccess may be null if sun.awt.AppContext class hasn't 730 * been loaded. If so, it implies that AWTSecurityManager is not our 731 * SecurityManager and we can use a local static variable. 732 * This works around a build time issue. 733 */ 734 private static TimeZone getDefaultInAppContext() { 735 // JavaAWTAccess provides access implementation-private methods without using reflection. 736 JavaAWTAccess javaAWTAccess = SharedSecrets.getJavaAWTAccess(); 737 738 if (javaAWTAccess == null) { 739 return mainAppContextDefault; 740 } else { 741 if (!javaAWTAccess.isDisposed()) { 742 TimeZone tz = (TimeZone) 743 javaAWTAccess.get(TimeZone.class); 744 if (tz == null && javaAWTAccess.isMainAppContext()) { 745 return mainAppContextDefault; 746 } else { 747 return tz; 748 } 749 } 750 } 751 return null; 752 } 753 754 /** 755 * Sets the default TimeZone in the AppContext to the given 756 * tz. null is handled special: do nothing if any AppContext 757 * hasn't been used, remove the default TimeZone in the 758 * AppContext otherwise. 759 * 760 * Note that javaAWTAccess may be null if sun.awt.AppContext class hasn't 761 * been loaded. If so, it implies that AWTSecurityManager is not our 762 * SecurityManager and we can use a local static variable. 763 * This works around a build time issue. 764 */ 765 private static void setDefaultInAppContext(TimeZone tz) { 766 // JavaAWTAccess provides access implementation-private methods without using reflection. 767 JavaAWTAccess javaAWTAccess = SharedSecrets.getJavaAWTAccess(); 768 769 if (javaAWTAccess == null) { 770 mainAppContextDefault = tz; 771 } else { 772 if (!javaAWTAccess.isDisposed()) { 773 javaAWTAccess.put(TimeZone.class, tz); 774 if (javaAWTAccess.isMainAppContext()) { 775 mainAppContextDefault = null; 776 } 777 } 778 } 779 } 780 781 /** 782 * Returns true if this zone has the same rule and offset as another zone. 783 * That is, if this zone differs only in ID, if at all. Returns false 784 * if the other zone is null. 785 * @param other the <code>TimeZone</code> object to be compared with 786 * @return true if the other zone is not null and is the same as this one, 787 * with the possible exception of the ID 788 * @since 1.2 789 */ 790 public boolean hasSameRules(TimeZone other) { 791 return other != null && getRawOffset() == other.getRawOffset() && 792 useDaylightTime() == other.useDaylightTime(); 793 } 794 795 /** 796 * Creates a copy of this <code>TimeZone</code>. 797 * 798 * @return a clone of this <code>TimeZone</code> 799 */ 800 public Object clone() 801 { 802 try { 803 TimeZone other = (TimeZone) super.clone(); 804 other.ID = ID; 805 return other; 806 } catch (CloneNotSupportedException e) { 807 throw new InternalError(e); 808 } 809 } 810 811 /** 812 * The null constant as a TimeZone. 813 */ 814 static final TimeZone NO_TIMEZONE = null; 815 816 // =======================privates=============================== 817 818 /** 819 * The string identifier of this <code>TimeZone</code>. This is a 820 * programmatic identifier used internally to look up <code>TimeZone</code> 821 * objects from the system table and also to map them to their localized 822 * display names. <code>ID</code> values are unique in the system 823 * table but may not be for dynamically created zones. 824 * @serial 825 */ 826 private String ID; 827 private static volatile TimeZone defaultTimeZone; 828 829 static final String GMT_ID = "GMT"; 830 private static final int GMT_ID_LENGTH = 3; 831 832 // a static TimeZone we can reference if no AppContext is in place 833 private static volatile TimeZone mainAppContextDefault; 834 835 /** 836 * Parses a custom time zone identifier and returns a corresponding zone. 837 * This method doesn't support the RFC 822 time zone format. (e.g., +hhmm) 838 * 839 * @param id a string of the <a href="#CustomID">custom ID form</a>. 840 * @return a newly created TimeZone with the given offset and 841 * no daylight saving time, or null if the id cannot be parsed. 842 */ 843 private static final TimeZone parseCustomTimeZone(String id) { 844 int length; 845 846 // Error if the length of id isn't long enough or id doesn't 847 // start with "GMT". 848 if ((length = id.length()) < (GMT_ID_LENGTH + 2) || 849 id.indexOf(GMT_ID) != 0) { 850 return null; 851 } 852 853 ZoneInfo zi; 854 855 // First, we try to find it in the cache with the given 856 // id. Even the id is not normalized, the returned ZoneInfo 857 // should have its normalized id. 858 zi = ZoneInfoFile.getZoneInfo(id); 859 if (zi != null) { 860 return zi; 861 } 862 863 int index = GMT_ID_LENGTH; 864 boolean negative = false; 865 char c = id.charAt(index++); 866 if (c == '-') { 867 negative = true; 868 } else if (c != '+') { 869 return null; 870 } 871 872 int hours = 0; 873 int num = 0; 874 int countDelim = 0; 875 int len = 0; 876 while (index < length) { 877 c = id.charAt(index++); 878 if (c == ':') { 879 if (countDelim > 0) { 880 return null; 881 } 882 if (len > 2) { 883 return null; 884 } 885 hours = num; 886 countDelim++; 887 num = 0; 888 len = 0; 889 continue; 890 } 891 if (c < '0' || c > '9') { 892 return null; 893 } 894 num = num * 10 + (c - '0'); 895 len++; 896 } 897 if (index != length) { 898 return null; 899 } 900 if (countDelim == 0) { 901 if (len <= 2) { 902 hours = num; 903 num = 0; 904 } else { 905 hours = num / 100; 906 num %= 100; 907 } 908 } else { 909 if (len != 2) { 910 return null; 911 } 912 } 913 if (hours > 23 || num > 59) { 914 return null; 915 } 916 int gmtOffset = (hours * 60 + num) * 60 * 1000; 917 918 if (gmtOffset == 0) { 919 zi = ZoneInfoFile.getZoneInfo(GMT_ID); 920 if (negative) { 921 zi.setID("GMT-00:00"); 922 } else { 923 zi.setID("GMT+00:00"); 924 } 925 } else { 926 zi = ZoneInfoFile.getCustomTimeZone(id, negative ? -gmtOffset : gmtOffset); 927 } 928 return zi; 929 } 930 }