1 /*
   2  * Copyright (c) 1996, 2020, 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.text;
  40 
  41 import java.io.IOException;
  42 import java.io.ObjectOutputStream;
  43 import java.io.Serializable;
  44 import java.lang.ref.SoftReference;
  45 import java.text.spi.DateFormatSymbolsProvider;
  46 import java.util.Arrays;
  47 import java.util.Locale;
  48 import java.util.Objects;
  49 import java.util.ResourceBundle;
  50 import java.util.concurrent.ConcurrentHashMap;
  51 import java.util.concurrent.ConcurrentMap;
  52 import sun.util.locale.provider.CalendarDataUtility;
  53 import sun.util.locale.provider.LocaleProviderAdapter;
  54 import sun.util.locale.provider.LocaleServiceProviderPool;
  55 import sun.util.locale.provider.ResourceBundleBasedAdapter;
  56 import sun.util.locale.provider.TimeZoneNameUtility;
  57 
  58 /**
  59  * {@code DateFormatSymbols} is a public class for encapsulating
  60  * localizable date-time formatting data, such as the names of the
  61  * months, the names of the days of the week, and the time zone data.
  62  * {@code SimpleDateFormat} uses
  63  * {@code DateFormatSymbols} to encapsulate this information.
  64  *
  65  * <p>
  66  * Typically you shouldn't use {@code DateFormatSymbols} directly.
  67  * Rather, you are encouraged to create a date-time formatter with the
  68  * {@code DateFormat} class's factory methods: {@code getTimeInstance},
  69  * {@code getDateInstance}, or {@code getDateTimeInstance}.
  70  * These methods automatically create a {@code DateFormatSymbols} for
  71  * the formatter so that you don't have to. After the
  72  * formatter is created, you may modify its format pattern using the
  73  * {@code setPattern} method. For more information about
  74  * creating formatters using {@code DateFormat}'s factory methods,
  75  * see {@link DateFormat}.
  76  *
  77  * <p>
  78  * If you decide to create a date-time formatter with a specific
  79  * format pattern for a specific locale, you can do so with:
  80  * <blockquote>
  81  * <pre>
  82  * new SimpleDateFormat(aPattern, DateFormatSymbols.getInstance(aLocale)).
  83  * </pre>
  84  * </blockquote>
  85  *
  86  * <p>If the locale contains "rg" (region override)
  87  * <a href="../util/Locale.html#def_locale_extension">Unicode extension</a>,
  88  * the symbols are overridden for the designated region.
  89  *
  90  * <p>
  91  * {@code DateFormatSymbols} objects are cloneable. When you obtain
  92  * a {@code DateFormatSymbols} object, feel free to modify the
  93  * date-time formatting data. For instance, you can replace the localized
  94  * date-time format pattern characters with the ones that you feel easy
  95  * to remember. Or you can change the representative cities
  96  * to your favorite ones.
  97  *
  98  * <p>
  99  * New {@code DateFormatSymbols} subclasses may be added to support
 100  * {@code SimpleDateFormat} for date-time formatting for additional locales.
 101  *
 102  * @see          DateFormat
 103  * @see          SimpleDateFormat
 104  * @see          java.util.SimpleTimeZone
 105  * @author       Chen-Lieh Huang
 106  * @since 1.1
 107  */
 108 public class DateFormatSymbols implements Serializable, Cloneable {
 109 
 110     /**
 111      * Construct a DateFormatSymbols object by loading format data from
 112      * resources for the default {@link java.util.Locale.Category#FORMAT FORMAT}
 113      * locale. This constructor can only
 114      * construct instances for the locales supported by the Java
 115      * runtime environment, not for those supported by installed
 116      * {@link java.text.spi.DateFormatSymbolsProvider DateFormatSymbolsProvider}
 117      * implementations. For full locale coverage, use the
 118      * {@link #getInstance(Locale) getInstance} method.
 119      * <p>This is equivalent to calling
 120      * {@link #DateFormatSymbols(Locale)
 121      *     DateFormatSymbols(Locale.getDefault(Locale.Category.FORMAT))}.
 122      * @see #getInstance()
 123      * @see java.util.Locale#getDefault(java.util.Locale.Category)
 124      * @see java.util.Locale.Category#FORMAT
 125      * @throws     java.util.MissingResourceException
 126      *             if the resources for the default locale cannot be
 127      *             found or cannot be loaded.
 128      */
 129     public DateFormatSymbols()
 130     {
 131         initializeData(Locale.getDefault(Locale.Category.FORMAT));
 132     }
 133 
 134     /**
 135      * Construct a DateFormatSymbols object by loading format data from
 136      * resources for the given locale. This constructor can only
 137      * construct instances for the locales supported by the Java
 138      * runtime environment, not for those supported by installed
 139      * {@link java.text.spi.DateFormatSymbolsProvider DateFormatSymbolsProvider}
 140      * implementations. For full locale coverage, use the
 141      * {@link #getInstance(Locale) getInstance} method.
 142      *
 143      * @param locale the desired locale
 144      * @see #getInstance(Locale)
 145      * @throws     java.util.MissingResourceException
 146      *             if the resources for the specified locale cannot be
 147      *             found or cannot be loaded.
 148      */
 149     public DateFormatSymbols(Locale locale)
 150     {
 151         initializeData(locale);
 152     }
 153 
 154     /**
 155      * Constructs an uninitialized DateFormatSymbols.
 156      */
 157     private DateFormatSymbols(boolean flag) {
 158     }
 159 
 160     /**
 161      * Era strings. For example: "AD" and "BC".  An array of 2 strings,
 162      * indexed by {@code Calendar.BC} and {@code Calendar.AD}.
 163      * @serial
 164      */
 165     String eras[] = null;
 166 
 167     /**
 168      * Month strings. For example: "January", "February", etc.  An array
 169      * of 13 strings (some calendars have 13 months), indexed by
 170      * {@code Calendar.JANUARY}, {@code Calendar.FEBRUARY}, etc.
 171      * @serial
 172      */
 173     String months[] = null;
 174 
 175     /**
 176      * Short month strings. For example: "Jan", "Feb", etc.  An array of
 177      * 13 strings (some calendars have 13 months), indexed by
 178      * {@code Calendar.JANUARY}, {@code Calendar.FEBRUARY}, etc.
 179      * @serial
 180      */
 181     String shortMonths[] = null;
 182 
 183     /**
 184      * Weekday strings. For example: "Sunday", "Monday", etc.  An array
 185      * of 8 strings, indexed by {@code Calendar.SUNDAY},
 186      * {@code Calendar.MONDAY}, etc.
 187      * The element {@code weekdays[0]} is ignored.
 188      * @serial
 189      */
 190     String weekdays[] = null;
 191 
 192     /**
 193      * Short weekday strings. For example: "Sun", "Mon", etc.  An array
 194      * of 8 strings, indexed by {@code Calendar.SUNDAY},
 195      * {@code Calendar.MONDAY}, etc.
 196      * The element {@code shortWeekdays[0]} is ignored.
 197      * @serial
 198      */
 199     String shortWeekdays[] = null;
 200 
 201     /**
 202      * AM and PM strings. For example: "AM" and "PM".  An array of
 203      * 2 strings, indexed by {@code Calendar.AM} and
 204      * {@code Calendar.PM}.
 205      * @serial
 206      */
 207     String ampms[] = null;
 208 
 209     /**
 210      * Localized names of time zones in this locale.  This is a
 211      * two-dimensional array of strings of size <em>n</em> by <em>m</em>,
 212      * where <em>m</em> is at least 5.  Each of the <em>n</em> rows is an
 213      * entry containing the localized names for a single {@code TimeZone}.
 214      * Each such row contains (with {@code i} ranging from
 215      * 0..<em>n</em>-1):
 216      * <ul>
 217      * <li>{@code zoneStrings[i][0]} - time zone ID</li>
 218      * <li>{@code zoneStrings[i][1]} - long name of zone in standard
 219      * time</li>
 220      * <li>{@code zoneStrings[i][2]} - short name of zone in
 221      * standard time</li>
 222      * <li>{@code zoneStrings[i][3]} - long name of zone in daylight
 223      * saving time</li>
 224      * <li>{@code zoneStrings[i][4]} - short name of zone in daylight
 225      * saving time</li>
 226      * </ul>
 227      * The zone ID is <em>not</em> localized; it's one of the valid IDs of
 228      * the {@link java.util.TimeZone TimeZone} class that are not
 229      * <a href="../util/TimeZone.html#CustomID">custom IDs</a>.
 230      * All other entries are localized names.
 231      * @see java.util.TimeZone
 232      * @serial
 233      */
 234     String zoneStrings[][] = null;
 235 
 236     /**
 237      * Indicates that zoneStrings is set externally with setZoneStrings() method.
 238      */
 239     transient boolean isZoneStringsSet = false;
 240 
 241     /**
 242      * Unlocalized date-time pattern characters. For example: 'y', 'd', etc.
 243      * All locales use the same these unlocalized pattern characters.
 244      */
 245     static final String  patternChars = "GyMdkHmsSEDFwWahKzZYuXL";
 246 
 247     static final int PATTERN_ERA                  =  0; // G
 248     static final int PATTERN_YEAR                 =  1; // y
 249     static final int PATTERN_MONTH                =  2; // M
 250     static final int PATTERN_DAY_OF_MONTH         =  3; // d
 251     static final int PATTERN_HOUR_OF_DAY1         =  4; // k
 252     static final int PATTERN_HOUR_OF_DAY0         =  5; // H
 253     static final int PATTERN_MINUTE               =  6; // m
 254     static final int PATTERN_SECOND               =  7; // s
 255     static final int PATTERN_MILLISECOND          =  8; // S
 256     static final int PATTERN_DAY_OF_WEEK          =  9; // E
 257     static final int PATTERN_DAY_OF_YEAR          = 10; // D
 258     static final int PATTERN_DAY_OF_WEEK_IN_MONTH = 11; // F
 259     static final int PATTERN_WEEK_OF_YEAR         = 12; // w
 260     static final int PATTERN_WEEK_OF_MONTH        = 13; // W
 261     static final int PATTERN_AM_PM                = 14; // a
 262     static final int PATTERN_HOUR1                = 15; // h
 263     static final int PATTERN_HOUR0                = 16; // K
 264     static final int PATTERN_ZONE_NAME            = 17; // z
 265     static final int PATTERN_ZONE_VALUE           = 18; // Z
 266     static final int PATTERN_WEEK_YEAR            = 19; // Y
 267     static final int PATTERN_ISO_DAY_OF_WEEK      = 20; // u
 268     static final int PATTERN_ISO_ZONE             = 21; // X
 269     static final int PATTERN_MONTH_STANDALONE     = 22; // L
 270 
 271     /**
 272      * Localized date-time pattern characters. For example, a locale may
 273      * wish to use 'u' rather than 'y' to represent years in its date format
 274      * pattern strings.
 275      * This string must be exactly 18 characters long, with the index of
 276      * the characters described by {@code DateFormat.ERA_FIELD},
 277      * {@code DateFormat.YEAR_FIELD}, etc.  Thus, if the string were
 278      * "Xz...", then localized patterns would use 'X' for era and 'z' for year.
 279      * @serial
 280      */
 281     String  localPatternChars = null;
 282 
 283     /**
 284      * The locale which is used for initializing this DateFormatSymbols object.
 285      *
 286      * @since 1.6
 287      * @serial
 288      */
 289     Locale locale = null;
 290 
 291     /* use serialVersionUID from JDK 1.1.4 for interoperability */
 292     @java.io.Serial
 293     static final long serialVersionUID = -5987973545549424702L;
 294 
 295     /**
 296      * Returns an array of all locales for which the
 297      * {@code getInstance} methods of this class can return
 298      * localized instances.
 299      * The returned array represents the union of locales supported by the
 300      * Java runtime and by installed
 301      * {@link java.text.spi.DateFormatSymbolsProvider DateFormatSymbolsProvider}
 302      * implementations.  It must contain at least a {@code Locale}
 303      * instance equal to {@link java.util.Locale#US Locale.US}.
 304      *
 305      * @return An array of locales for which localized
 306      *         {@code DateFormatSymbols} instances are available.
 307      * @since 1.6
 308      */
 309     public static Locale[] getAvailableLocales() {
 310         LocaleServiceProviderPool pool=
 311             LocaleServiceProviderPool.getPool(DateFormatSymbolsProvider.class);
 312         return pool.getAvailableLocales();
 313     }
 314 
 315     /**
 316      * Gets the {@code DateFormatSymbols} instance for the default
 317      * locale.  This method provides access to {@code DateFormatSymbols}
 318      * instances for locales supported by the Java runtime itself as well
 319      * as for those supported by installed
 320      * {@link java.text.spi.DateFormatSymbolsProvider DateFormatSymbolsProvider}
 321      * implementations.
 322      * <p>This is equivalent to calling {@link #getInstance(Locale)
 323      *     getInstance(Locale.getDefault(Locale.Category.FORMAT))}.
 324      * @see java.util.Locale#getDefault(java.util.Locale.Category)
 325      * @see java.util.Locale.Category#FORMAT
 326      * @return a {@code DateFormatSymbols} instance.
 327      * @since 1.6
 328      */
 329     public static final DateFormatSymbols getInstance() {
 330         return getInstance(Locale.getDefault(Locale.Category.FORMAT));
 331     }
 332 
 333     /**
 334      * Gets the {@code DateFormatSymbols} instance for the specified
 335      * locale.  This method provides access to {@code DateFormatSymbols}
 336      * instances for locales supported by the Java runtime itself as well
 337      * as for those supported by installed
 338      * {@link java.text.spi.DateFormatSymbolsProvider DateFormatSymbolsProvider}
 339      * implementations.
 340      * @param locale the given locale.
 341      * @return a {@code DateFormatSymbols} instance.
 342      * @throws    NullPointerException if {@code locale} is null
 343      * @since 1.6
 344      */
 345     public static final DateFormatSymbols getInstance(Locale locale) {
 346         DateFormatSymbols dfs = getProviderInstance(locale);
 347         if (dfs != null) {
 348             return dfs;
 349         }
 350         throw new RuntimeException("DateFormatSymbols instance creation failed.");
 351     }
 352 
 353     /**
 354      * Returns a DateFormatSymbols provided by a provider or found in
 355      * the cache. Note that this method returns a cached instance,
 356      * not its clone. Therefore, the instance should never be given to
 357      * an application.
 358      */
 359     static final DateFormatSymbols getInstanceRef(Locale locale) {
 360         DateFormatSymbols dfs = getProviderInstance(locale);
 361         if (dfs != null) {
 362             return dfs;
 363         }
 364         throw new RuntimeException("DateFormatSymbols instance creation failed.");
 365     }
 366 
 367     private static DateFormatSymbols getProviderInstance(Locale locale) {
 368         LocaleProviderAdapter adapter = LocaleProviderAdapter.getAdapter(DateFormatSymbolsProvider.class, locale);
 369         DateFormatSymbolsProvider provider = adapter.getDateFormatSymbolsProvider();
 370         DateFormatSymbols dfsyms = provider.getInstance(locale);
 371         if (dfsyms == null) {
 372             provider = LocaleProviderAdapter.forJRE().getDateFormatSymbolsProvider();
 373             dfsyms = provider.getInstance(locale);
 374         }
 375         return dfsyms;
 376     }
 377 
 378     /**
 379      * Gets era strings. For example: "AD" and "BC".
 380      * @return the era strings.
 381      */
 382     public String[] getEras() {
 383         return Arrays.copyOf(eras, eras.length);
 384     }
 385 
 386     /**
 387      * Sets era strings. For example: "AD" and "BC".
 388      * @param newEras the new era strings.
 389      */
 390     public void setEras(String[] newEras) {
 391         eras = Arrays.copyOf(newEras, newEras.length);
 392         cachedHashCode = 0;
 393     }
 394 
 395     /**
 396      * Gets month strings. For example: "January", "February", etc.
 397      * An array with either 12 or 13 elements will be returned depending
 398      * on whether or not {@link java.util.Calendar#UNDECIMBER Calendar.UNDECIMBER}
 399      * is supported. Use
 400      * {@link java.util.Calendar#JANUARY Calendar.JANUARY},
 401      * {@link java.util.Calendar#FEBRUARY Calendar.FEBRUARY},
 402      * etc. to index the result array.
 403      *
 404      * <p>If the language requires different forms for formatting and
 405      * stand-alone usages, this method returns month names in the
 406      * formatting form. For example, the preferred month name for
 407      * January in the Czech language is <em>ledna</em> in the
 408      * formatting form, while it is <em>leden</em> in the stand-alone
 409      * form. This method returns {@code "ledna"} in this case. Refer
 410      * to the <a href="http://unicode.org/reports/tr35/#Calendar_Elements">
 411      * Calendar Elements in the Unicode Locale Data Markup Language
 412      * (LDML) specification</a> for more details.
 413      *
 414      * @implSpec This method returns 13 elements since
 415      * {@link java.util.Calendar#UNDECIMBER Calendar.UNDECIMBER} is supported.
 416      * @return the month strings.
 417      */
 418     public String[] getMonths() {
 419         return Arrays.copyOf(months, months.length);
 420     }
 421 
 422     /**
 423      * Sets month strings. For example: "January", "February", etc.
 424      * @param newMonths the new month strings. The array should
 425      * be indexed by {@link java.util.Calendar#JANUARY Calendar.JANUARY},
 426      * {@link java.util.Calendar#FEBRUARY Calendar.FEBRUARY}, etc.
 427      */
 428     public void setMonths(String[] newMonths) {
 429         months = Arrays.copyOf(newMonths, newMonths.length);
 430         cachedHashCode = 0;
 431     }
 432 
 433     /**
 434      * Gets short month strings. For example: "Jan", "Feb", etc.
 435      * An array with either 12 or 13 elements will be returned depending
 436      * on whether or not {@link java.util.Calendar#UNDECIMBER Calendar.UNDECIMBER}
 437      * is supported. Use
 438      * {@link java.util.Calendar#JANUARY Calendar.JANUARY},
 439      * {@link java.util.Calendar#FEBRUARY Calendar.FEBRUARY},
 440      * etc. to index the result array.
 441      *
 442      * <p>If the language requires different forms for formatting and
 443      * stand-alone usages, this method returns short month names in
 444      * the formatting form. For example, the preferred abbreviation
 445      * for January in the Catalan language is <em>de gen.</em> in the
 446      * formatting form, while it is <em>gen.</em> in the stand-alone
 447      * form. This method returns {@code "de gen."} in this case. Refer
 448      * to the <a href="http://unicode.org/reports/tr35/#Calendar_Elements">
 449      * Calendar Elements in the Unicode Locale Data Markup Language
 450      * (LDML) specification</a> for more details.
 451      *
 452      * @implSpec This method returns 13 elements since
 453      * {@link java.util.Calendar#UNDECIMBER Calendar.UNDECIMBER} is supported.
 454      * @return the short month strings.
 455      */
 456     public String[] getShortMonths() {
 457         return Arrays.copyOf(shortMonths, shortMonths.length);
 458     }
 459 
 460     /**
 461      * Sets short month strings. For example: "Jan", "Feb", etc.
 462      * @param newShortMonths the new short month strings. The array should
 463      * be indexed by {@link java.util.Calendar#JANUARY Calendar.JANUARY},
 464      * {@link java.util.Calendar#FEBRUARY Calendar.FEBRUARY}, etc.
 465      */
 466     public void setShortMonths(String[] newShortMonths) {
 467         shortMonths = Arrays.copyOf(newShortMonths, newShortMonths.length);
 468         cachedHashCode = 0;
 469     }
 470 
 471     /**
 472      * Gets weekday strings. For example: "Sunday", "Monday", etc.
 473      * @return the weekday strings. Use
 474      * {@link java.util.Calendar#SUNDAY Calendar.SUNDAY},
 475      * {@link java.util.Calendar#MONDAY Calendar.MONDAY}, etc. to index
 476      * the result array.
 477      */
 478     public String[] getWeekdays() {
 479         return Arrays.copyOf(weekdays, weekdays.length);
 480     }
 481 
 482     /**
 483      * Sets weekday strings. For example: "Sunday", "Monday", etc.
 484      * @param newWeekdays the new weekday strings. The array should
 485      * be indexed by {@link java.util.Calendar#SUNDAY Calendar.SUNDAY},
 486      * {@link java.util.Calendar#MONDAY Calendar.MONDAY}, etc.
 487      */
 488     public void setWeekdays(String[] newWeekdays) {
 489         weekdays = Arrays.copyOf(newWeekdays, newWeekdays.length);
 490         cachedHashCode = 0;
 491     }
 492 
 493     /**
 494      * Gets short weekday strings. For example: "Sun", "Mon", etc.
 495      * @return the short weekday strings. Use
 496      * {@link java.util.Calendar#SUNDAY Calendar.SUNDAY},
 497      * {@link java.util.Calendar#MONDAY Calendar.MONDAY}, etc. to index
 498      * the result array.
 499      */
 500     public String[] getShortWeekdays() {
 501         return Arrays.copyOf(shortWeekdays, shortWeekdays.length);
 502     }
 503 
 504     /**
 505      * Sets short weekday strings. For example: "Sun", "Mon", etc.
 506      * @param newShortWeekdays the new short weekday strings. The array should
 507      * be indexed by {@link java.util.Calendar#SUNDAY Calendar.SUNDAY},
 508      * {@link java.util.Calendar#MONDAY Calendar.MONDAY}, etc.
 509      */
 510     public void setShortWeekdays(String[] newShortWeekdays) {
 511         shortWeekdays = Arrays.copyOf(newShortWeekdays, newShortWeekdays.length);
 512         cachedHashCode = 0;
 513     }
 514 
 515     /**
 516      * Gets ampm strings. For example: "AM" and "PM".
 517      * @return the ampm strings.
 518      */
 519     public String[] getAmPmStrings() {
 520         return Arrays.copyOf(ampms, ampms.length);
 521     }
 522 
 523     /**
 524      * Sets ampm strings. For example: "AM" and "PM".
 525      * @param newAmpms the new ampm strings.
 526      */
 527     public void setAmPmStrings(String[] newAmpms) {
 528         ampms = Arrays.copyOf(newAmpms, newAmpms.length);
 529         cachedHashCode = 0;
 530     }
 531 
 532     /**
 533      * Gets time zone strings.  Use of this method is discouraged; use
 534      * {@link java.util.TimeZone#getDisplayName() TimeZone.getDisplayName()}
 535      * instead.
 536      * <p>
 537      * The value returned is a
 538      * two-dimensional array of strings of size <em>n</em> by <em>m</em>,
 539      * where <em>m</em> is at least 5.  Each of the <em>n</em> rows is an
 540      * entry containing the localized names for a single {@code TimeZone}.
 541      * Each such row contains (with {@code i} ranging from
 542      * 0..<em>n</em>-1):
 543      * <ul>
 544      * <li>{@code zoneStrings[i][0]} - time zone ID</li>
 545      * <li>{@code zoneStrings[i][1]} - long name of zone in standard
 546      * time</li>
 547      * <li>{@code zoneStrings[i][2]} - short name of zone in
 548      * standard time</li>
 549      * <li>{@code zoneStrings[i][3]} - long name of zone in daylight
 550      * saving time</li>
 551      * <li>{@code zoneStrings[i][4]} - short name of zone in daylight
 552      * saving time</li>
 553      * </ul>
 554      * The zone ID is <em>not</em> localized; it's one of the valid IDs of
 555      * the {@link java.util.TimeZone TimeZone} class that are not
 556      * <a href="../util/TimeZone.html#CustomID">custom IDs</a>.
 557      * All other entries are localized names.  If a zone does not implement
 558      * daylight saving time, the daylight saving time names should not be used.
 559      * <p>
 560      * If {@link #setZoneStrings(String[][]) setZoneStrings} has been called
 561      * on this {@code DateFormatSymbols} instance, then the strings
 562      * provided by that call are returned. Otherwise, the returned array
 563      * contains names provided by the Java runtime and by installed
 564      * {@link java.util.spi.TimeZoneNameProvider TimeZoneNameProvider}
 565      * implementations.
 566      *
 567      * @return the time zone strings.
 568      * @see #setZoneStrings(String[][])
 569      */
 570     public String[][] getZoneStrings() {
 571         return getZoneStringsImpl(true);
 572     }
 573 
 574     /**
 575      * Sets time zone strings.  The argument must be a
 576      * two-dimensional array of strings of size <em>n</em> by <em>m</em>,
 577      * where <em>m</em> is at least 5.  Each of the <em>n</em> rows is an
 578      * entry containing the localized names for a single {@code TimeZone}.
 579      * Each such row contains (with {@code i} ranging from
 580      * 0..<em>n</em>-1):
 581      * <ul>
 582      * <li>{@code zoneStrings[i][0]} - time zone ID</li>
 583      * <li>{@code zoneStrings[i][1]} - long name of zone in standard
 584      * time</li>
 585      * <li>{@code zoneStrings[i][2]} - short name of zone in
 586      * standard time</li>
 587      * <li>{@code zoneStrings[i][3]} - long name of zone in daylight
 588      * saving time</li>
 589      * <li>{@code zoneStrings[i][4]} - short name of zone in daylight
 590      * saving time</li>
 591      * </ul>
 592      * The zone ID is <em>not</em> localized; it's one of the valid IDs of
 593      * the {@link java.util.TimeZone TimeZone} class that are not
 594      * <a href="../util/TimeZone.html#CustomID">custom IDs</a>.
 595      * All other entries are localized names.
 596      *
 597      * @param newZoneStrings the new time zone strings.
 598      * @throws    IllegalArgumentException if the length of any row in
 599      *    {@code newZoneStrings} is less than 5
 600      * @throws    NullPointerException if {@code newZoneStrings} is null
 601      * @see #getZoneStrings()
 602      */
 603     public void setZoneStrings(String[][] newZoneStrings) {
 604         String[][] aCopy = new String[newZoneStrings.length][];
 605         for (int i = 0; i < newZoneStrings.length; ++i) {
 606             int len = newZoneStrings[i].length;
 607             if (len < 5) {
 608                 throw new IllegalArgumentException();
 609             }
 610             aCopy[i] = Arrays.copyOf(newZoneStrings[i], len);
 611         }
 612         zoneStrings = aCopy;
 613         isZoneStringsSet = true;
 614         cachedHashCode = 0;
 615     }
 616 
 617     /**
 618      * Gets localized date-time pattern characters. For example: 'u', 't', etc.
 619      * @return the localized date-time pattern characters.
 620      */
 621     public String getLocalPatternChars() {
 622         return localPatternChars;
 623     }
 624 
 625     /**
 626      * Sets localized date-time pattern characters. For example: 'u', 't', etc.
 627      * @param newLocalPatternChars the new localized date-time
 628      * pattern characters.
 629      */
 630     public void setLocalPatternChars(String newLocalPatternChars) {
 631         // Call toString() to throw an NPE in case the argument is null
 632         localPatternChars = newLocalPatternChars.toString();
 633         cachedHashCode = 0;
 634     }
 635 
 636     /**
 637      * Overrides Cloneable
 638      */
 639     public Object clone()
 640     {
 641         try
 642         {
 643             DateFormatSymbols other = (DateFormatSymbols)super.clone();
 644             copyMembers(this, other);
 645             return other;
 646         } catch (CloneNotSupportedException e) {
 647             throw new InternalError(e);
 648         }
 649     }
 650 
 651     /**
 652      * Override hashCode.
 653      * Generates a hash code for the DateFormatSymbols object.
 654      */
 655     @Override
 656     public int hashCode() {
 657         int hashCode = cachedHashCode;
 658         if (hashCode == 0) {
 659             hashCode = 5;
 660             hashCode = 11 * hashCode + Arrays.hashCode(eras);
 661             hashCode = 11 * hashCode + Arrays.hashCode(months);
 662             hashCode = 11 * hashCode + Arrays.hashCode(shortMonths);
 663             hashCode = 11 * hashCode + Arrays.hashCode(weekdays);
 664             hashCode = 11 * hashCode + Arrays.hashCode(shortWeekdays);
 665             hashCode = 11 * hashCode + Arrays.hashCode(ampms);
 666             hashCode = 11 * hashCode + Arrays.deepHashCode(getZoneStringsWrapper());
 667             hashCode = 11 * hashCode + Objects.hashCode(localPatternChars);
 668             if (hashCode != 0) {
 669                 cachedHashCode = hashCode;
 670             }
 671         }
 672 
 673         return hashCode;
 674     }
 675 
 676     /**
 677      * Override equals
 678      */
 679     public boolean equals(Object obj)
 680     {
 681         if (this == obj) return true;
 682         if (obj == null || getClass() != obj.getClass()) return false;
 683         DateFormatSymbols that = (DateFormatSymbols) obj;
 684         return (Arrays.equals(eras, that.eras)
 685                 && Arrays.equals(months, that.months)
 686                 && Arrays.equals(shortMonths, that.shortMonths)
 687                 && Arrays.equals(weekdays, that.weekdays)
 688                 && Arrays.equals(shortWeekdays, that.shortWeekdays)
 689                 && Arrays.equals(ampms, that.ampms)
 690                 && Arrays.deepEquals(getZoneStringsWrapper(), that.getZoneStringsWrapper())
 691                 && ((localPatternChars != null
 692                   && localPatternChars.equals(that.localPatternChars))
 693                  || (localPatternChars == null
 694                   && that.localPatternChars == null)));
 695     }
 696 
 697     // =======================privates===============================
 698 
 699     /**
 700      * Useful constant for defining time zone offsets.
 701      */
 702     static final int millisPerHour = 60*60*1000;
 703 
 704     /**
 705      * Cache to hold DateFormatSymbols instances per Locale.
 706      */
 707     private static final ConcurrentMap<Locale, SoftReference<DateFormatSymbols>> cachedInstances
 708         = new ConcurrentHashMap<>(3);
 709 
 710     private transient int lastZoneIndex;
 711 
 712     /**
 713      * Cached hash code
 714      */
 715     transient volatile int cachedHashCode;
 716 
 717     /**
 718      * Initializes this DateFormatSymbols with the locale data. This method uses
 719      * a cached DateFormatSymbols instance for the given locale if available. If
 720      * there's no cached one, this method creates an uninitialized instance and
 721      * populates its fields from the resource bundle for the locale, and caches
 722      * the instance. Note: zoneStrings isn't initialized in this method.
 723      */
 724     private void initializeData(Locale locale) {
 725         SoftReference<DateFormatSymbols> ref = cachedInstances.get(locale);
 726         DateFormatSymbols dfs;
 727         if (ref == null || (dfs = ref.get()) == null) {
 728             if (ref != null) {
 729                 // Remove the empty SoftReference
 730                 cachedInstances.remove(locale, ref);
 731             }
 732             dfs = new DateFormatSymbols(false);
 733 
 734             // check for region override
 735             Locale override = CalendarDataUtility.findRegionOverride(locale);
 736 
 737             // Initialize the fields from the ResourceBundle for locale.
 738             LocaleProviderAdapter adapter
 739                 = LocaleProviderAdapter.getAdapter(DateFormatSymbolsProvider.class, override);
 740             // Avoid any potential recursions
 741             if (!(adapter instanceof ResourceBundleBasedAdapter)) {
 742                 adapter = LocaleProviderAdapter.getResourceBundleBased();
 743             }
 744             ResourceBundle resource
 745                 = ((ResourceBundleBasedAdapter)adapter).getLocaleData().getDateFormatData(override);
 746 
 747             dfs.locale = locale;
 748             // JRE and CLDR use different keys
 749             // JRE: Eras, short.Eras and narrow.Eras
 750             // CLDR: long.Eras, Eras and narrow.Eras
 751             if (resource.containsKey("Eras")) {
 752                 dfs.eras = resource.getStringArray("Eras");
 753             } else if (resource.containsKey("long.Eras")) {
 754                 dfs.eras = resource.getStringArray("long.Eras");
 755             } else if (resource.containsKey("short.Eras")) {
 756                 dfs.eras = resource.getStringArray("short.Eras");
 757             }
 758             dfs.months = resource.getStringArray("MonthNames");
 759             dfs.shortMonths = resource.getStringArray("MonthAbbreviations");
 760             dfs.ampms = resource.getStringArray("AmPmMarkers");
 761             dfs.localPatternChars = resource.getString("DateTimePatternChars");
 762 
 763             // Day of week names are stored in a 1-based array.
 764             dfs.weekdays = toOneBasedArray(resource.getStringArray("DayNames"));
 765             dfs.shortWeekdays = toOneBasedArray(resource.getStringArray("DayAbbreviations"));
 766 
 767             // Put dfs in the cache
 768             ref = new SoftReference<>(dfs);
 769             SoftReference<DateFormatSymbols> x = cachedInstances.putIfAbsent(locale, ref);
 770             if (x != null) {
 771                 DateFormatSymbols y = x.get();
 772                 if (y == null) {
 773                     // Replace the empty SoftReference with ref.
 774                     cachedInstances.replace(locale, x, ref);
 775                 } else {
 776                     ref = x;
 777                     dfs = y;
 778                 }
 779             }
 780         }
 781 
 782         // Copy the field values from dfs to this instance.
 783         copyMembers(dfs, this);
 784     }
 785 
 786     private static String[] toOneBasedArray(String[] src) {
 787         int len = src.length;
 788         String[] dst = new String[len + 1];
 789         dst[0] = "";
 790         for (int i = 0; i < len; i++) {
 791             dst[i + 1] = src[i];
 792         }
 793         return dst;
 794     }
 795 
 796     /**
 797      * Package private: used by SimpleDateFormat
 798      * Gets the index for the given time zone ID to obtain the time zone
 799      * strings for formatting. The time zone ID is just for programmatic
 800      * lookup. NOT LOCALIZED!!!
 801      * @param ID the given time zone ID.
 802      * @return the index of the given time zone ID.  Returns -1 if
 803      * the given time zone ID can't be located in the DateFormatSymbols object.
 804      * @see java.util.SimpleTimeZone
 805      */
 806     final int getZoneIndex(String ID) {
 807         String[][] zoneStrings = getZoneStringsWrapper();
 808 
 809         /*
 810          * getZoneIndex has been re-written for performance reasons. instead of
 811          * traversing the zoneStrings array every time, we cache the last used zone
 812          * index
 813          */
 814         if (lastZoneIndex < zoneStrings.length && ID.equals(zoneStrings[lastZoneIndex][0])) {
 815             return lastZoneIndex;
 816         }
 817 
 818         /* slow path, search entire list */
 819         for (int index = 0; index < zoneStrings.length; index++) {
 820             if (ID.equals(zoneStrings[index][0])) {
 821                 lastZoneIndex = index;
 822                 return index;
 823             }
 824         }
 825 
 826         return -1;
 827     }
 828 
 829     /**
 830      * Wrapper method to the getZoneStrings(), which is called from inside
 831      * the java.text package and not to mutate the returned arrays, so that
 832      * it does not need to create a defensive copy.
 833      */
 834     final String[][] getZoneStringsWrapper() {
 835         if (isSubclassObject()) {
 836             return getZoneStrings();
 837         } else {
 838             return getZoneStringsImpl(false);
 839         }
 840     }
 841 
 842     private String[][] getZoneStringsImpl(boolean needsCopy) {
 843         if (zoneStrings == null) {
 844             zoneStrings = TimeZoneNameUtility.getZoneStrings(locale);
 845         }
 846 
 847         if (!needsCopy) {
 848             return zoneStrings;
 849         }
 850 
 851         int len = zoneStrings.length;
 852         String[][] aCopy = new String[len][];
 853         for (int i = 0; i < len; i++) {
 854             aCopy[i] = Arrays.copyOf(zoneStrings[i], zoneStrings[i].length);
 855         }
 856         return aCopy;
 857     }
 858 
 859     private boolean isSubclassObject() {
 860         return !getClass().getName().equals("java.text.DateFormatSymbols");
 861     }
 862 
 863     /**
 864      * Clones all the data members from the source DateFormatSymbols to
 865      * the target DateFormatSymbols.
 866      *
 867      * @param src the source DateFormatSymbols.
 868      * @param dst the target DateFormatSymbols.
 869      */
 870     private void copyMembers(DateFormatSymbols src, DateFormatSymbols dst)
 871     {
 872         dst.locale = src.locale;
 873         dst.eras = Arrays.copyOf(src.eras, src.eras.length);
 874         dst.months = Arrays.copyOf(src.months, src.months.length);
 875         dst.shortMonths = Arrays.copyOf(src.shortMonths, src.shortMonths.length);
 876         dst.weekdays = Arrays.copyOf(src.weekdays, src.weekdays.length);
 877         dst.shortWeekdays = Arrays.copyOf(src.shortWeekdays, src.shortWeekdays.length);
 878         dst.ampms = Arrays.copyOf(src.ampms, src.ampms.length);
 879         if (src.zoneStrings != null) {
 880             dst.zoneStrings = src.getZoneStringsImpl(true);
 881         } else {
 882             dst.zoneStrings = null;
 883         }
 884         dst.localPatternChars = src.localPatternChars;
 885         dst.cachedHashCode = 0;
 886     }
 887 
 888     /**
 889      * Write out the default serializable data, after ensuring the
 890      * {@code zoneStrings} field is initialized in order to make
 891      * sure the backward compatibility.
 892      *
 893      * @since 1.6
 894      */
 895     @java.io.Serial
 896     private void writeObject(ObjectOutputStream stream) throws IOException {
 897         if (zoneStrings == null) {
 898             zoneStrings = TimeZoneNameUtility.getZoneStrings(locale);
 899         }
 900         stream.defaultWriteObject();
 901     }
 902 }