1 /*
   2  * Copyright (c) 1996, 2017, 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</code> 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</code> uses
  63  * <code>DateFormatSymbols</code> to encapsulate this information.
  64  *
  65  * <p>
  66  * Typically you shouldn't use <code>DateFormatSymbols</code> directly.
  67  * Rather, you are encouraged to create a date-time formatter with the
  68  * <code>DateFormat</code> class's factory methods: <code>getTimeInstance</code>,
  69  * <code>getDateInstance</code>, or <code>getDateTimeInstance</code>.
  70  * These methods automatically create a <code>DateFormatSymbols</code> 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</code> method. For more information about
  74  * creating formatters using <code>DateFormat</code>'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</code> objects are cloneable. When you obtain
  92  * a <code>DateFormatSymbols</code> 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</code> subclasses may be added to support
 100  * <code>SimpleDateFormat</code> 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      * @exception  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      * @exception  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</code> and <code>Calendar.AD</code>.
 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>, <code>Calendar.FEBRUARY</code>, 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>, <code>Calendar.FEBRUARY</code>, etc.
 179 
 180      * @serial
 181      */
 182     String shortMonths[] = null;
 183 
 184     /**
 185      * Weekday strings. For example: "Sunday", "Monday", etc.  An array
 186      * of 8 strings, indexed by <code>Calendar.SUNDAY</code>,
 187      * <code>Calendar.MONDAY</code>, etc.
 188      * The element <code>weekdays[0]</code> is ignored.
 189      * @serial
 190      */
 191     String weekdays[] = null;
 192 
 193     /**
 194      * Short weekday strings. For example: "Sun", "Mon", etc.  An array
 195      * of 8 strings, indexed by <code>Calendar.SUNDAY</code>,
 196      * <code>Calendar.MONDAY</code>, etc.
 197      * The element <code>shortWeekdays[0]</code> is ignored.
 198      * @serial
 199      */
 200     String shortWeekdays[] = null;
 201 
 202     /**
 203      * AM and PM strings. For example: "AM" and "PM".  An array of
 204      * 2 strings, indexed by <code>Calendar.AM</code> and
 205      * <code>Calendar.PM</code>.
 206      * @serial
 207      */
 208     String ampms[] = null;
 209 
 210     /**
 211      * Localized names of time zones in this locale.  This is a
 212      * two-dimensional array of strings of size <em>n</em> by <em>m</em>,
 213      * where <em>m</em> is at least 5.  Each of the <em>n</em> rows is an
 214      * entry containing the localized names for a single <code>TimeZone</code>.
 215      * Each such row contains (with <code>i</code> ranging from
 216      * 0..<em>n</em>-1):
 217      * <ul>
 218      * <li><code>zoneStrings[i][0]</code> - time zone ID</li>
 219      * <li><code>zoneStrings[i][1]</code> - long name of zone in standard
 220      * time</li>
 221      * <li><code>zoneStrings[i][2]</code> - short name of zone in
 222      * standard time</li>
 223      * <li><code>zoneStrings[i][3]</code> - long name of zone in daylight
 224      * saving time</li>
 225      * <li><code>zoneStrings[i][4]</code> - short name of zone in daylight
 226      * saving time</li>
 227      * </ul>
 228      * The zone ID is <em>not</em> localized; it's one of the valid IDs of
 229      * the {@link java.util.TimeZone TimeZone} class that are not
 230      * <a href="../util/TimeZone.html#CustomID">custom IDs</a>.
 231      * All other entries are localized names.
 232      * @see java.util.TimeZone
 233      * @serial
 234      */
 235     String zoneStrings[][] = null;
 236 
 237     /**
 238      * Indicates that zoneStrings is set externally with setZoneStrings() method.
 239      */
 240     transient boolean isZoneStringsSet = false;
 241 
 242     /**
 243      * Unlocalized date-time pattern characters. For example: 'y', 'd', etc.
 244      * All locales use the same these unlocalized pattern characters.
 245      */
 246     static final String  patternChars = "GyMdkHmsSEDFwWahKzZYuXL";
 247 
 248     static final int PATTERN_ERA                  =  0; // G
 249     static final int PATTERN_YEAR                 =  1; // y
 250     static final int PATTERN_MONTH                =  2; // M
 251     static final int PATTERN_DAY_OF_MONTH         =  3; // d
 252     static final int PATTERN_HOUR_OF_DAY1         =  4; // k
 253     static final int PATTERN_HOUR_OF_DAY0         =  5; // H
 254     static final int PATTERN_MINUTE               =  6; // m
 255     static final int PATTERN_SECOND               =  7; // s
 256     static final int PATTERN_MILLISECOND          =  8; // S
 257     static final int PATTERN_DAY_OF_WEEK          =  9; // E
 258     static final int PATTERN_DAY_OF_YEAR          = 10; // D
 259     static final int PATTERN_DAY_OF_WEEK_IN_MONTH = 11; // F
 260     static final int PATTERN_WEEK_OF_YEAR         = 12; // w
 261     static final int PATTERN_WEEK_OF_MONTH        = 13; // W
 262     static final int PATTERN_AM_PM                = 14; // a
 263     static final int PATTERN_HOUR1                = 15; // h
 264     static final int PATTERN_HOUR0                = 16; // K
 265     static final int PATTERN_ZONE_NAME            = 17; // z
 266     static final int PATTERN_ZONE_VALUE           = 18; // Z
 267     static final int PATTERN_WEEK_YEAR            = 19; // Y
 268     static final int PATTERN_ISO_DAY_OF_WEEK      = 20; // u
 269     static final int PATTERN_ISO_ZONE             = 21; // X
 270     static final int PATTERN_MONTH_STANDALONE     = 22; // L
 271 
 272     /**
 273      * Localized date-time pattern characters. For example, a locale may
 274      * wish to use 'u' rather than 'y' to represent years in its date format
 275      * pattern strings.
 276      * This string must be exactly 18 characters long, with the index of
 277      * the characters described by <code>DateFormat.ERA_FIELD</code>,
 278      * <code>DateFormat.YEAR_FIELD</code>, etc.  Thus, if the string were
 279      * "Xz...", then localized patterns would use 'X' for era and 'z' for year.
 280      * @serial
 281      */
 282     String  localPatternChars = null;
 283 
 284     /**
 285      * The locale which is used for initializing this DateFormatSymbols object.
 286      *
 287      * @since 1.6
 288      * @serial
 289      */
 290     Locale locale = null;
 291 
 292     /* use serialVersionUID from JDK 1.1.4 for interoperability */
 293     static final long serialVersionUID = -5987973545549424702L;
 294 
 295     /**
 296      * Returns an array of all locales for which the
 297      * <code>getInstance</code> 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</code>
 303      * instance equal to {@link java.util.Locale#US Locale.US}.
 304      *
 305      * @return An array of locales for which localized
 306      *         <code>DateFormatSymbols</code> 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</code> instance for the default
 317      * locale.  This method provides access to <code>DateFormatSymbols</code>
 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</code> 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</code> instance for the specified
 335      * locale.  This method provides access to <code>DateFormatSymbols</code>
 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</code> instance.
 342      * @exception NullPointerException if <code>locale</code> 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      *
 398      * <p>If the language requires different forms for formatting and
 399      * stand-alone usages, this method returns month names in the
 400      * formatting form. For example, the preferred month name for
 401      * January in the Czech language is <em>ledna</em> in the
 402      * formatting form, while it is <em>leden</em> in the stand-alone
 403      * form. This method returns {@code "ledna"} in this case. Refer
 404      * to the <a href="http://unicode.org/reports/tr35/#Calendar_Elements">
 405      * Calendar Elements in the Unicode Locale Data Markup Language
 406      * (LDML) specification</a> for more details.
 407      * 
 408      * @implNote The default implementation returns month string
 409      * array of 13 elements, the thirteenth element is for
 410      * {@link java.util.Calendar#UNDECIMBER Calendar.UNDECIMBER},
 411      * in which an empty string is returned for
 412      * {@code GregorianCalendar}.
 413      *
 414      * @return the month strings. Use
 415      * {@link java.util.Calendar#JANUARY Calendar.JANUARY},
 416      * {@link java.util.Calendar#FEBRUARY Calendar.FEBRUARY},
 417      * etc. to index the result array.
 418      */
 419     public String[] getMonths() {
 420         return Arrays.copyOf(months, months.length);
 421     }
 422 
 423     /**
 424      * Sets month strings. For example: "January", "February", etc.
 425      * @param newMonths the new month strings. The array should
 426      * be indexed by {@link java.util.Calendar#JANUARY Calendar.JANUARY},
 427      * {@link java.util.Calendar#FEBRUARY Calendar.FEBRUARY}, etc.
 428      */
 429     public void setMonths(String[] newMonths) {
 430         months = Arrays.copyOf(newMonths, newMonths.length);
 431         cachedHashCode = 0;
 432     }
 433 
 434     /**
 435      * Gets short month strings. For example: "Jan", "Feb", etc.
 436      *
 437      * <p>If the language requires different forms for formatting and
 438      * stand-alone usages, this method returns short month names in
 439      * the formatting form. For example, the preferred abbreviation
 440      * for January in the Catalan language is <em>de gen.</em> in the
 441      * formatting form, while it is <em>gen.</em> in the stand-alone
 442      * form. This method returns {@code "de gen."} in this case. Refer
 443      * to the <a href="http://unicode.org/reports/tr35/#Calendar_Elements">
 444      * Calendar Elements in the Unicode Locale Data Markup Language
 445      * (LDML) specification</a> for more details.
 446      *
 447      * @implNote The default implementation returns short month string
 448      * array of 13 elements, the thirteenth element is for
 449      * {@link java.util.Calendar#UNDECIMBER Calendar.UNDECIMBER},
 450      * in which an empty string is returned for
 451      * {@code GregorianCalendar}.
 452      * 
 453      * @return the short month strings. Use
 454      * {@link java.util.Calendar#JANUARY Calendar.JANUARY},
 455      * {@link java.util.Calendar#FEBRUARY Calendar.FEBRUARY},
 456      * etc. to index the result array.
 457      */
 458     public String[] getShortMonths() {
 459         return Arrays.copyOf(shortMonths, shortMonths.length);
 460     }
 461 
 462     /**
 463      * Sets short month strings. For example: "Jan", "Feb", etc.
 464      * @param newShortMonths the new short month strings. The array should
 465      * be indexed by {@link java.util.Calendar#JANUARY Calendar.JANUARY},
 466      * {@link java.util.Calendar#FEBRUARY Calendar.FEBRUARY}, etc.
 467      */
 468     public void setShortMonths(String[] newShortMonths) {
 469         shortMonths = Arrays.copyOf(newShortMonths, newShortMonths.length);
 470         cachedHashCode = 0;
 471     }
 472 
 473     /**
 474      * Gets weekday strings. For example: "Sunday", "Monday", etc.
 475      * @return the weekday strings. Use
 476      * {@link java.util.Calendar#SUNDAY Calendar.SUNDAY},
 477      * {@link java.util.Calendar#MONDAY Calendar.MONDAY}, etc. to index
 478      * the result array.
 479      */
 480     public String[] getWeekdays() {
 481         return Arrays.copyOf(weekdays, weekdays.length);
 482     }
 483 
 484     /**
 485      * Sets weekday strings. For example: "Sunday", "Monday", etc.
 486      * @param newWeekdays the new weekday strings. The array should
 487      * be indexed by {@link java.util.Calendar#SUNDAY Calendar.SUNDAY},
 488      * {@link java.util.Calendar#MONDAY Calendar.MONDAY}, etc.
 489      */
 490     public void setWeekdays(String[] newWeekdays) {
 491         weekdays = Arrays.copyOf(newWeekdays, newWeekdays.length);
 492         cachedHashCode = 0;
 493     }
 494 
 495     /**
 496      * Gets short weekday strings. For example: "Sun", "Mon", etc.
 497      * @return the short weekday strings. Use
 498      * {@link java.util.Calendar#SUNDAY Calendar.SUNDAY},
 499      * {@link java.util.Calendar#MONDAY Calendar.MONDAY}, etc. to index
 500      * the result array.
 501      */
 502     public String[] getShortWeekdays() {
 503         return Arrays.copyOf(shortWeekdays, shortWeekdays.length);
 504     }
 505 
 506     /**
 507      * Sets short weekday strings. For example: "Sun", "Mon", etc.
 508      * @param newShortWeekdays the new short weekday strings. The array should
 509      * be indexed by {@link java.util.Calendar#SUNDAY Calendar.SUNDAY},
 510      * {@link java.util.Calendar#MONDAY Calendar.MONDAY}, etc.
 511      */
 512     public void setShortWeekdays(String[] newShortWeekdays) {
 513         shortWeekdays = Arrays.copyOf(newShortWeekdays, newShortWeekdays.length);
 514         cachedHashCode = 0;
 515     }
 516 
 517     /**
 518      * Gets ampm strings. For example: "AM" and "PM".
 519      * @return the ampm strings.
 520      */
 521     public String[] getAmPmStrings() {
 522         return Arrays.copyOf(ampms, ampms.length);
 523     }
 524 
 525     /**
 526      * Sets ampm strings. For example: "AM" and "PM".
 527      * @param newAmpms the new ampm strings.
 528      */
 529     public void setAmPmStrings(String[] newAmpms) {
 530         ampms = Arrays.copyOf(newAmpms, newAmpms.length);
 531         cachedHashCode = 0;
 532     }
 533 
 534     /**
 535      * Gets time zone strings.  Use of this method is discouraged; use
 536      * {@link java.util.TimeZone#getDisplayName() TimeZone.getDisplayName()}
 537      * instead.
 538      * <p>
 539      * The value returned is a
 540      * two-dimensional array of strings of size <em>n</em> by <em>m</em>,
 541      * where <em>m</em> is at least 5.  Each of the <em>n</em> rows is an
 542      * entry containing the localized names for a single <code>TimeZone</code>.
 543      * Each such row contains (with <code>i</code> ranging from
 544      * 0..<em>n</em>-1):
 545      * <ul>
 546      * <li><code>zoneStrings[i][0]</code> - time zone ID</li>
 547      * <li><code>zoneStrings[i][1]</code> - long name of zone in standard
 548      * time</li>
 549      * <li><code>zoneStrings[i][2]</code> - short name of zone in
 550      * standard time</li>
 551      * <li><code>zoneStrings[i][3]</code> - long name of zone in daylight
 552      * saving time</li>
 553      * <li><code>zoneStrings[i][4]</code> - short name of zone in daylight
 554      * saving time</li>
 555      * </ul>
 556      * The zone ID is <em>not</em> localized; it's one of the valid IDs of
 557      * the {@link java.util.TimeZone TimeZone} class that are not
 558      * <a href="../util/TimeZone.html#CustomID">custom IDs</a>.
 559      * All other entries are localized names.  If a zone does not implement
 560      * daylight saving time, the daylight saving time names should not be used.
 561      * <p>
 562      * If {@link #setZoneStrings(String[][]) setZoneStrings} has been called
 563      * on this <code>DateFormatSymbols</code> instance, then the strings
 564      * provided by that call are returned. Otherwise, the returned array
 565      * contains names provided by the Java runtime and by installed
 566      * {@link java.util.spi.TimeZoneNameProvider TimeZoneNameProvider}
 567      * implementations.
 568      *
 569      * @return the time zone strings.
 570      * @see #setZoneStrings(String[][])
 571      */
 572     public String[][] getZoneStrings() {
 573         return getZoneStringsImpl(true);
 574     }
 575 
 576     /**
 577      * Sets time zone strings.  The argument must be a
 578      * two-dimensional array of strings of size <em>n</em> by <em>m</em>,
 579      * where <em>m</em> is at least 5.  Each of the <em>n</em> rows is an
 580      * entry containing the localized names for a single <code>TimeZone</code>.
 581      * Each such row contains (with <code>i</code> ranging from
 582      * 0..<em>n</em>-1):
 583      * <ul>
 584      * <li><code>zoneStrings[i][0]</code> - time zone ID</li>
 585      * <li><code>zoneStrings[i][1]</code> - long name of zone in standard
 586      * time</li>
 587      * <li><code>zoneStrings[i][2]</code> - short name of zone in
 588      * standard time</li>
 589      * <li><code>zoneStrings[i][3]</code> - long name of zone in daylight
 590      * saving time</li>
 591      * <li><code>zoneStrings[i][4]</code> - short name of zone in daylight
 592      * saving time</li>
 593      * </ul>
 594      * The zone ID is <em>not</em> localized; it's one of the valid IDs of
 595      * the {@link java.util.TimeZone TimeZone} class that are not
 596      * <a href="../util/TimeZone.html#CustomID">custom IDs</a>.
 597      * All other entries are localized names.
 598      *
 599      * @param newZoneStrings the new time zone strings.
 600      * @exception IllegalArgumentException if the length of any row in
 601      *    <code>newZoneStrings</code> is less than 5
 602      * @exception NullPointerException if <code>newZoneStrings</code> is null
 603      * @see #getZoneStrings()
 604      */
 605     public void setZoneStrings(String[][] newZoneStrings) {
 606         String[][] aCopy = new String[newZoneStrings.length][];
 607         for (int i = 0; i < newZoneStrings.length; ++i) {
 608             int len = newZoneStrings[i].length;
 609             if (len < 5) {
 610                 throw new IllegalArgumentException();
 611             }
 612             aCopy[i] = Arrays.copyOf(newZoneStrings[i], len);
 613         }
 614         zoneStrings = aCopy;
 615         isZoneStringsSet = true;
 616         cachedHashCode = 0;
 617     }
 618 
 619     /**
 620      * Gets localized date-time pattern characters. For example: 'u', 't', etc.
 621      * @return the localized date-time pattern characters.
 622      */
 623     public String getLocalPatternChars() {
 624         return localPatternChars;
 625     }
 626 
 627     /**
 628      * Sets localized date-time pattern characters. For example: 'u', 't', etc.
 629      * @param newLocalPatternChars the new localized date-time
 630      * pattern characters.
 631      */
 632     public void setLocalPatternChars(String newLocalPatternChars) {
 633         // Call toString() to throw an NPE in case the argument is null
 634         localPatternChars = newLocalPatternChars.toString();
 635         cachedHashCode = 0;
 636     }
 637 
 638     /**
 639      * Overrides Cloneable
 640      */
 641     public Object clone()
 642     {
 643         try
 644         {
 645             DateFormatSymbols other = (DateFormatSymbols)super.clone();
 646             copyMembers(this, other);
 647             return other;
 648         } catch (CloneNotSupportedException e) {
 649             throw new InternalError(e);
 650         }
 651     }
 652 
 653     /**
 654      * Override hashCode.
 655      * Generates a hash code for the DateFormatSymbols object.
 656      */
 657     @Override
 658     public int hashCode() {
 659         int hashCode = cachedHashCode;
 660         if (hashCode == 0) {
 661             hashCode = 5;
 662             hashCode = 11 * hashCode + Arrays.hashCode(eras);
 663             hashCode = 11 * hashCode + Arrays.hashCode(months);
 664             hashCode = 11 * hashCode + Arrays.hashCode(shortMonths);
 665             hashCode = 11 * hashCode + Arrays.hashCode(weekdays);
 666             hashCode = 11 * hashCode + Arrays.hashCode(shortWeekdays);
 667             hashCode = 11 * hashCode + Arrays.hashCode(ampms);
 668             hashCode = 11 * hashCode + Arrays.deepHashCode(getZoneStringsWrapper());
 669             hashCode = 11 * hashCode + Objects.hashCode(localPatternChars);
 670             if (hashCode != 0) {
 671                 cachedHashCode = hashCode;
 672             }
 673         }
 674 
 675         return hashCode;
 676     }
 677 
 678     /**
 679      * Override equals
 680      */
 681     public boolean equals(Object obj)
 682     {
 683         if (this == obj) return true;
 684         if (obj == null || getClass() != obj.getClass()) return false;
 685         DateFormatSymbols that = (DateFormatSymbols) obj;
 686         return (Arrays.equals(eras, that.eras)
 687                 && Arrays.equals(months, that.months)
 688                 && Arrays.equals(shortMonths, that.shortMonths)
 689                 && Arrays.equals(weekdays, that.weekdays)
 690                 && Arrays.equals(shortWeekdays, that.shortWeekdays)
 691                 && Arrays.equals(ampms, that.ampms)
 692                 && Arrays.deepEquals(getZoneStringsWrapper(), that.getZoneStringsWrapper())
 693                 && ((localPatternChars != null
 694                   && localPatternChars.equals(that.localPatternChars))
 695                  || (localPatternChars == null
 696                   && that.localPatternChars == null)));
 697     }
 698 
 699     // =======================privates===============================
 700 
 701     /**
 702      * Useful constant for defining time zone offsets.
 703      */
 704     static final int millisPerHour = 60*60*1000;
 705 
 706     /**
 707      * Cache to hold DateFormatSymbols instances per Locale.
 708      */
 709     private static final ConcurrentMap<Locale, SoftReference<DateFormatSymbols>> cachedInstances
 710         = new ConcurrentHashMap<>(3);
 711 
 712     private transient int lastZoneIndex;
 713 
 714     /**
 715      * Cached hash code
 716      */
 717     transient volatile int cachedHashCode;
 718 
 719     /**
 720      * Initializes this DateFormatSymbols with the locale data. This method uses
 721      * a cached DateFormatSymbols instance for the given locale if available. If
 722      * there's no cached one, this method creates an uninitialized instance and
 723      * populates its fields from the resource bundle for the locale, and caches
 724      * the instance. Note: zoneStrings isn't initialized in this method.
 725      */
 726     private void initializeData(Locale locale) {
 727         SoftReference<DateFormatSymbols> ref = cachedInstances.get(locale);
 728         DateFormatSymbols dfs;
 729         if (ref == null || (dfs = ref.get()) == null) {
 730             if (ref != null) {
 731                 // Remove the empty SoftReference
 732                 cachedInstances.remove(locale, ref);
 733             }
 734             dfs = new DateFormatSymbols(false);
 735 
 736             // check for region override
 737             Locale override = CalendarDataUtility.findRegionOverride(locale);
 738 
 739             // Initialize the fields from the ResourceBundle for locale.
 740             LocaleProviderAdapter adapter
 741                 = LocaleProviderAdapter.getAdapter(DateFormatSymbolsProvider.class, override);
 742             // Avoid any potential recursions
 743             if (!(adapter instanceof ResourceBundleBasedAdapter)) {
 744                 adapter = LocaleProviderAdapter.getResourceBundleBased();
 745             }
 746             ResourceBundle resource
 747                 = ((ResourceBundleBasedAdapter)adapter).getLocaleData().getDateFormatData(override);
 748 
 749             dfs.locale = locale;
 750             // JRE and CLDR use different keys
 751             // JRE: Eras, short.Eras and narrow.Eras
 752             // CLDR: long.Eras, Eras and narrow.Eras
 753             if (resource.containsKey("Eras")) {
 754                 dfs.eras = resource.getStringArray("Eras");
 755             } else if (resource.containsKey("long.Eras")) {
 756                 dfs.eras = resource.getStringArray("long.Eras");
 757             } else if (resource.containsKey("short.Eras")) {
 758                 dfs.eras = resource.getStringArray("short.Eras");
 759             }
 760             dfs.months = resource.getStringArray("MonthNames");
 761             dfs.shortMonths = resource.getStringArray("MonthAbbreviations");
 762             dfs.ampms = resource.getStringArray("AmPmMarkers");
 763             dfs.localPatternChars = resource.getString("DateTimePatternChars");
 764 
 765             // Day of week names are stored in a 1-based array.
 766             dfs.weekdays = toOneBasedArray(resource.getStringArray("DayNames"));
 767             dfs.shortWeekdays = toOneBasedArray(resource.getStringArray("DayAbbreviations"));
 768 
 769             // Put dfs in the cache
 770             ref = new SoftReference<>(dfs);
 771             SoftReference<DateFormatSymbols> x = cachedInstances.putIfAbsent(locale, ref);
 772             if (x != null) {
 773                 DateFormatSymbols y = x.get();
 774                 if (y == null) {
 775                     // Replace the empty SoftReference with ref.
 776                     cachedInstances.replace(locale, x, ref);
 777                 } else {
 778                     ref = x;
 779                     dfs = y;
 780                 }
 781             }
 782         }
 783 
 784         // Copy the field values from dfs to this instance.
 785         copyMembers(dfs, this);
 786     }
 787 
 788     private static String[] toOneBasedArray(String[] src) {
 789         int len = src.length;
 790         String[] dst = new String[len + 1];
 791         dst[0] = "";
 792         for (int i = 0; i < len; i++) {
 793             dst[i + 1] = src[i];
 794         }
 795         return dst;
 796     }
 797 
 798     /**
 799      * Package private: used by SimpleDateFormat
 800      * Gets the index for the given time zone ID to obtain the time zone
 801      * strings for formatting. The time zone ID is just for programmatic
 802      * lookup. NOT LOCALIZED!!!
 803      * @param ID the given time zone ID.
 804      * @return the index of the given time zone ID.  Returns -1 if
 805      * the given time zone ID can't be located in the DateFormatSymbols object.
 806      * @see java.util.SimpleTimeZone
 807      */
 808     final int getZoneIndex(String ID) {
 809         String[][] zoneStrings = getZoneStringsWrapper();
 810 
 811         /*
 812          * getZoneIndex has been re-written for performance reasons. instead of
 813          * traversing the zoneStrings array every time, we cache the last used zone
 814          * index
 815          */
 816         if (lastZoneIndex < zoneStrings.length && ID.equals(zoneStrings[lastZoneIndex][0])) {
 817             return lastZoneIndex;
 818         }
 819 
 820         /* slow path, search entire list */
 821         for (int index = 0; index < zoneStrings.length; index++) {
 822             if (ID.equals(zoneStrings[index][0])) {
 823                 lastZoneIndex = index;
 824                 return index;
 825             }
 826         }
 827 
 828         return -1;
 829     }
 830 
 831     /**
 832      * Wrapper method to the getZoneStrings(), which is called from inside
 833      * the java.text package and not to mutate the returned arrays, so that
 834      * it does not need to create a defensive copy.
 835      */
 836     final String[][] getZoneStringsWrapper() {
 837         if (isSubclassObject()) {
 838             return getZoneStrings();
 839         } else {
 840             return getZoneStringsImpl(false);
 841         }
 842     }
 843 
 844     private String[][] getZoneStringsImpl(boolean needsCopy) {
 845         if (zoneStrings == null) {
 846             zoneStrings = TimeZoneNameUtility.getZoneStrings(locale);
 847         }
 848 
 849         if (!needsCopy) {
 850             return zoneStrings;
 851         }
 852 
 853         int len = zoneStrings.length;
 854         String[][] aCopy = new String[len][];
 855         for (int i = 0; i < len; i++) {
 856             aCopy[i] = Arrays.copyOf(zoneStrings[i], zoneStrings[i].length);
 857         }
 858         return aCopy;
 859     }
 860 
 861     private boolean isSubclassObject() {
 862         return !getClass().getName().equals("java.text.DateFormatSymbols");
 863     }
 864 
 865     /**
 866      * Clones all the data members from the source DateFormatSymbols to
 867      * the target DateFormatSymbols.
 868      *
 869      * @param src the source DateFormatSymbols.
 870      * @param dst the target DateFormatSymbols.
 871      */
 872     private void copyMembers(DateFormatSymbols src, DateFormatSymbols dst)
 873     {
 874         dst.locale = src.locale;
 875         dst.eras = Arrays.copyOf(src.eras, src.eras.length);
 876         dst.months = Arrays.copyOf(src.months, src.months.length);
 877         dst.shortMonths = Arrays.copyOf(src.shortMonths, src.shortMonths.length);
 878         dst.weekdays = Arrays.copyOf(src.weekdays, src.weekdays.length);
 879         dst.shortWeekdays = Arrays.copyOf(src.shortWeekdays, src.shortWeekdays.length);
 880         dst.ampms = Arrays.copyOf(src.ampms, src.ampms.length);
 881         if (src.zoneStrings != null) {
 882             dst.zoneStrings = src.getZoneStringsImpl(true);
 883         } else {
 884             dst.zoneStrings = null;
 885         }
 886         dst.localPatternChars = src.localPatternChars;
 887         dst.cachedHashCode = 0;
 888     }
 889 
 890     /**
 891      * Write out the default serializable data, after ensuring the
 892      * <code>zoneStrings</code> field is initialized in order to make
 893      * sure the backward compatibility.
 894      *
 895      * @since 1.6
 896      */
 897     private void writeObject(ObjectOutputStream stream) throws IOException {
 898         if (zoneStrings == null) {
 899             zoneStrings = TimeZoneNameUtility.getZoneStrings(locale);
 900         }
 901         stream.defaultWriteObject();
 902     }
 903 }