1 /*
   2  * Copyright (c) 1996, 2013, 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.TimeZone;
  51 import java.util.concurrent.ConcurrentHashMap;
  52 import java.util.concurrent.ConcurrentMap;
  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>
  87  * <code>DateFormatSymbols</code> objects are cloneable. When you obtain
  88  * a <code>DateFormatSymbols</code> object, feel free to modify the
  89  * date-time formatting data. For instance, you can replace the localized
  90  * date-time format pattern characters with the ones that you feel easy
  91  * to remember. Or you can change the representative cities
  92  * to your favorite ones.
  93  *
  94  * <p>
  95  * New <code>DateFormatSymbols</code> subclasses may be added to support
  96  * <code>SimpleDateFormat</code> for date-time formatting for additional locales.
  97 
  98  * @see          DateFormat
  99  * @see          SimpleDateFormat
 100  * @see          java.util.SimpleTimeZone
 101  * @author       Chen-Lieh Huang
 102  */
 103 public class DateFormatSymbols implements Serializable, Cloneable {
 104 
 105     /**
 106      * Construct a DateFormatSymbols object by loading format data from
 107      * resources for the default {@link java.util.Locale.Category#FORMAT FORMAT}
 108      * locale. This constructor can only
 109      * construct instances for the locales supported by the Java
 110      * runtime environment, not for those supported by installed
 111      * {@link java.text.spi.DateFormatSymbolsProvider DateFormatSymbolsProvider}
 112      * implementations. For full locale coverage, use the
 113      * {@link #getInstance(Locale) getInstance} method.
 114      * <p>This is equivalent to calling
 115      * {@link #DateFormatSymbols(Locale)
 116      *     DateFormatSymbols(Locale.getDefault(Locale.Category.FORMAT))}.
 117      * @see #getInstance()
 118      * @see java.util.Locale#getDefault(java.util.Locale.Category)
 119      * @see java.util.Locale.Category#FORMAT
 120      * @exception  java.util.MissingResourceException
 121      *             if the resources for the default locale cannot be
 122      *             found or cannot be loaded.
 123      */
 124     public DateFormatSymbols()
 125     {
 126         initializeData(Locale.getDefault(Locale.Category.FORMAT));
 127     }
 128 
 129     /**
 130      * Construct a DateFormatSymbols object by loading format data from
 131      * resources for the given locale. This constructor can only
 132      * construct instances for the locales supported by the Java
 133      * runtime environment, not for those supported by installed
 134      * {@link java.text.spi.DateFormatSymbolsProvider DateFormatSymbolsProvider}
 135      * implementations. For full locale coverage, use the
 136      * {@link #getInstance(Locale) getInstance} method.
 137      *
 138      * @param locale the desired locale
 139      * @see #getInstance(Locale)
 140      * @exception  java.util.MissingResourceException
 141      *             if the resources for the specified locale cannot be
 142      *             found or cannot be loaded.
 143      */
 144     public DateFormatSymbols(Locale locale)
 145     {
 146         initializeData(locale);
 147     }
 148 
 149     /**
 150      * Era strings. For example: "AD" and "BC".  An array of 2 strings,
 151      * indexed by <code>Calendar.BC</code> and <code>Calendar.AD</code>.
 152      * @serial
 153      */
 154     String eras[] = null;
 155 
 156     /**
 157      * Month strings. For example: "January", "February", etc.  An array
 158      * of 13 strings (some calendars have 13 months), indexed by
 159      * <code>Calendar.JANUARY</code>, <code>Calendar.FEBRUARY</code>, etc.
 160      * @serial
 161      */
 162     String months[] = null;
 163 
 164     /**
 165      * Short month strings. For example: "Jan", "Feb", etc.  An array of
 166      * 13 strings (some calendars have 13 months), indexed by
 167      * <code>Calendar.JANUARY</code>, <code>Calendar.FEBRUARY</code>, etc.
 168 
 169      * @serial
 170      */
 171     String shortMonths[] = null;
 172 
 173     /**
 174      * Weekday strings. For example: "Sunday", "Monday", etc.  An array
 175      * of 8 strings, indexed by <code>Calendar.SUNDAY</code>,
 176      * <code>Calendar.MONDAY</code>, etc.
 177      * The element <code>weekdays[0]</code> is ignored.
 178      * @serial
 179      */
 180     String weekdays[] = null;
 181 
 182     /**
 183      * Short weekday strings. For example: "Sun", "Mon", etc.  An array
 184      * of 8 strings, indexed by <code>Calendar.SUNDAY</code>,
 185      * <code>Calendar.MONDAY</code>, etc.
 186      * The element <code>shortWeekdays[0]</code> is ignored.
 187      * @serial
 188      */
 189     String shortWeekdays[] = null;
 190 
 191     /**
 192      * AM and PM strings. For example: "AM" and "PM".  An array of
 193      * 2 strings, indexed by <code>Calendar.AM</code> and
 194      * <code>Calendar.PM</code>.
 195      * @serial
 196      */
 197     String ampms[] = null;
 198 
 199     /**
 200      * Localized names of time zones in this locale.  This is a
 201      * two-dimensional array of strings of size <em>n</em> by <em>m</em>,
 202      * where <em>m</em> is at least 5.  Each of the <em>n</em> rows is an
 203      * entry containing the localized names for a single <code>TimeZone</code>.
 204      * Each such row contains (with <code>i</code> ranging from
 205      * 0..<em>n</em>-1):
 206      * <ul>
 207      * <li><code>zoneStrings[i][0]</code> - time zone ID</li>
 208      * <li><code>zoneStrings[i][1]</code> - long name of zone in standard
 209      * time</li>
 210      * <li><code>zoneStrings[i][2]</code> - short name of zone in
 211      * standard time</li>
 212      * <li><code>zoneStrings[i][3]</code> - long name of zone in daylight
 213      * saving time</li>
 214      * <li><code>zoneStrings[i][4]</code> - short name of zone in daylight
 215      * saving time</li>
 216      * </ul>
 217      * The zone ID is <em>not</em> localized; it's one of the valid IDs of
 218      * the {@link java.util.TimeZone TimeZone} class that are not
 219      * <a href="../java/util/TimeZone.html#CustomID">custom IDs</a>.
 220      * All other entries are localized names.
 221      * @see java.util.TimeZone
 222      * @serial
 223      */
 224     String zoneStrings[][] = null;
 225 
 226     /**
 227      * Indicates that zoneStrings is set externally with setZoneStrings() method.
 228      */
 229     transient boolean isZoneStringsSet = false;
 230 
 231     /**
 232      * Unlocalized date-time pattern characters. For example: 'y', 'd', etc.
 233      * All locales use the same these unlocalized pattern characters.
 234      */
 235     static final String  patternChars = "GyMdkHmsSEDFwWahKzZYuXL";
 236 
 237     static final int PATTERN_ERA                  =  0; // G
 238     static final int PATTERN_YEAR                 =  1; // y
 239     static final int PATTERN_MONTH                =  2; // M
 240     static final int PATTERN_DAY_OF_MONTH         =  3; // d
 241     static final int PATTERN_HOUR_OF_DAY1         =  4; // k
 242     static final int PATTERN_HOUR_OF_DAY0         =  5; // H
 243     static final int PATTERN_MINUTE               =  6; // m
 244     static final int PATTERN_SECOND               =  7; // s
 245     static final int PATTERN_MILLISECOND          =  8; // S
 246     static final int PATTERN_DAY_OF_WEEK          =  9; // E
 247     static final int PATTERN_DAY_OF_YEAR          = 10; // D
 248     static final int PATTERN_DAY_OF_WEEK_IN_MONTH = 11; // F
 249     static final int PATTERN_WEEK_OF_YEAR         = 12; // w
 250     static final int PATTERN_WEEK_OF_MONTH        = 13; // W
 251     static final int PATTERN_AM_PM                = 14; // a
 252     static final int PATTERN_HOUR1                = 15; // h
 253     static final int PATTERN_HOUR0                = 16; // K
 254     static final int PATTERN_ZONE_NAME            = 17; // z
 255     static final int PATTERN_ZONE_VALUE           = 18; // Z
 256     static final int PATTERN_WEEK_YEAR            = 19; // Y
 257     static final int PATTERN_ISO_DAY_OF_WEEK      = 20; // u
 258     static final int PATTERN_ISO_ZONE             = 21; // X
 259     static final int PATTERN_MONTH_STANDALONE     = 22; // L
 260 
 261     /**
 262      * Localized date-time pattern characters. For example, a locale may
 263      * wish to use 'u' rather than 'y' to represent years in its date format
 264      * pattern strings.
 265      * This string must be exactly 18 characters long, with the index of
 266      * the characters described by <code>DateFormat.ERA_FIELD</code>,
 267      * <code>DateFormat.YEAR_FIELD</code>, etc.  Thus, if the string were
 268      * "Xz...", then localized patterns would use 'X' for era and 'z' for year.
 269      * @serial
 270      */
 271     String  localPatternChars = null;
 272 
 273     /**
 274      * The locale which is used for initializing this DateFormatSymbols object.
 275      *
 276      * @since 1.6
 277      * @serial
 278      */
 279     Locale locale = null;
 280 
 281     /* use serialVersionUID from JDK 1.1.4 for interoperability */
 282     static final long serialVersionUID = -5987973545549424702L;
 283 
 284     /**
 285      * Returns an array of all locales for which the
 286      * <code>getInstance</code> methods of this class can return
 287      * localized instances.
 288      * The returned array represents the union of locales supported by the
 289      * Java runtime and by installed
 290      * {@link java.text.spi.DateFormatSymbolsProvider DateFormatSymbolsProvider}
 291      * implementations.  It must contain at least a <code>Locale</code>
 292      * instance equal to {@link java.util.Locale#US Locale.US}.
 293      *
 294      * @return An array of locales for which localized
 295      *         <code>DateFormatSymbols</code> instances are available.
 296      * @since 1.6
 297      */
 298     public static Locale[] getAvailableLocales() {
 299         LocaleServiceProviderPool pool=
 300             LocaleServiceProviderPool.getPool(DateFormatSymbolsProvider.class);
 301         return pool.getAvailableLocales();
 302     }
 303 
 304     /**
 305      * Gets the <code>DateFormatSymbols</code> instance for the default
 306      * locale.  This method provides access to <code>DateFormatSymbols</code>
 307      * instances for locales supported by the Java runtime itself as well
 308      * as for those supported by installed
 309      * {@link java.text.spi.DateFormatSymbolsProvider DateFormatSymbolsProvider}
 310      * implementations.
 311      * <p>This is equivalent to calling {@link #getInstance(Locale)
 312      *     getInstance(Locale.getDefault(Locale.Category.FORMAT))}.
 313      * @see java.util.Locale#getDefault(java.util.Locale.Category)
 314      * @see java.util.Locale.Category#FORMAT
 315      * @return a <code>DateFormatSymbols</code> instance.
 316      * @since 1.6
 317      */
 318     public static final DateFormatSymbols getInstance() {
 319         return getInstance(Locale.getDefault(Locale.Category.FORMAT));
 320     }
 321 
 322     /**
 323      * Gets the <code>DateFormatSymbols</code> instance for the specified
 324      * locale.  This method provides access to <code>DateFormatSymbols</code>
 325      * instances for locales supported by the Java runtime itself as well
 326      * as for those supported by installed
 327      * {@link java.text.spi.DateFormatSymbolsProvider DateFormatSymbolsProvider}
 328      * implementations.
 329      * @param locale the given locale.
 330      * @return a <code>DateFormatSymbols</code> instance.
 331      * @exception NullPointerException if <code>locale</code> is null
 332      * @since 1.6
 333      */
 334     public static final DateFormatSymbols getInstance(Locale locale) {
 335         DateFormatSymbols dfs = getProviderInstance(locale);
 336         if (dfs != null) {
 337             return dfs;
 338         }
 339         throw new RuntimeException("DateFormatSymbols instance creation failed.");
 340     }
 341 
 342     /**
 343      * Returns a DateFormatSymbols provided by a provider or found in
 344      * the cache. Note that this method returns a cached instance,
 345      * not its clone. Therefore, the instance should never be given to
 346      * an application.
 347      */
 348     static final DateFormatSymbols getInstanceRef(Locale locale) {
 349         DateFormatSymbols dfs = getProviderInstance(locale);
 350         if (dfs != null) {
 351             return dfs;
 352         }
 353         throw new RuntimeException("DateFormatSymbols instance creation failed.");
 354     }
 355 
 356     private static DateFormatSymbols getProviderInstance(Locale locale) {
 357         LocaleProviderAdapter adapter = LocaleProviderAdapter.getAdapter(DateFormatSymbolsProvider.class, locale);
 358         DateFormatSymbolsProvider provider = adapter.getDateFormatSymbolsProvider();
 359         DateFormatSymbols dfsyms = provider.getInstance(locale);
 360         if (dfsyms == null) {
 361             provider = LocaleProviderAdapter.forJRE().getDateFormatSymbolsProvider();
 362             dfsyms = provider.getInstance(locale);
 363         }
 364         return dfsyms;
 365     }
 366 
 367     /**
 368      * Gets era strings. For example: "AD" and "BC".
 369      * @return the era strings.
 370      */
 371     public String[] getEras() {
 372         return Arrays.copyOf(eras, eras.length);
 373     }
 374 
 375     /**
 376      * Sets era strings. For example: "AD" and "BC".
 377      * @param newEras the new era strings.
 378      */
 379     public void setEras(String[] newEras) {
 380         eras = Arrays.copyOf(newEras, newEras.length);
 381         cachedHashCode = 0;
 382     }
 383 
 384     /**
 385      * Gets month strings. For example: "January", "February", etc.
 386      *
 387      * <p>If the language requires different forms for formatting and
 388      * stand-alone usages, this method returns month names in the
 389      * formatting form. For example, the preferred month name for
 390      * January in the Czech language is <em>ledna</em> in the
 391      * formatting form, while it is <em>leden</em> in the stand-alone
 392      * form. This method returns {@code "ledna"} in this case. Refer
 393      * to the <a href="http://unicode.org/reports/tr35/#Calendar_Elements">
 394      * Calendar Elements in the Unicode Locale Data Markup Language
 395      * (LDML) specification</a> for more details.
 396      *
 397      * @return the month strings.
 398      */
 399     public String[] getMonths() {
 400         return Arrays.copyOf(months, months.length);
 401     }
 402 
 403     /**
 404      * Sets month strings. For example: "January", "February", etc.
 405      * @param newMonths the new month strings.
 406      */
 407     public void setMonths(String[] newMonths) {
 408         months = Arrays.copyOf(newMonths, newMonths.length);
 409         cachedHashCode = 0;
 410     }
 411 
 412     /**
 413      * Gets short month strings. For example: "Jan", "Feb", etc.
 414      *
 415      * <p>If the language requires different forms for formatting and
 416      * stand-alone usages, This method returns short month names in
 417      * the formatting form. For example, the preferred abbreviation
 418      * for January in the Catalan language is <em>de gen.</em> in the
 419      * formatting form, while it is <em>gen.</em> in the stand-alone
 420      * form. This method returns {@code "de gen."} in this case. Refer
 421      * to the <a href="http://unicode.org/reports/tr35/#Calendar_Elements">
 422      * Calendar Elements in the Unicode Locale Data Markup Language
 423      * (LDML) specification</a> for more details.
 424      *
 425      * @return the short month strings.
 426      */
 427     public String[] getShortMonths() {
 428         return Arrays.copyOf(shortMonths, shortMonths.length);
 429     }
 430 
 431     /**
 432      * Sets short month strings. For example: "Jan", "Feb", etc.
 433      * @param newShortMonths the new short month strings.
 434      */
 435     public void setShortMonths(String[] newShortMonths) {
 436         shortMonths = Arrays.copyOf(newShortMonths, newShortMonths.length);
 437         cachedHashCode = 0;
 438     }
 439 
 440     /**
 441      * Gets weekday strings. For example: "Sunday", "Monday", etc.
 442      * @return the weekday strings. Use <code>Calendar.SUNDAY</code>,
 443      * <code>Calendar.MONDAY</code>, etc. to index the result array.
 444      */
 445     public String[] getWeekdays() {
 446         return Arrays.copyOf(weekdays, weekdays.length);
 447     }
 448 
 449     /**
 450      * Sets weekday strings. For example: "Sunday", "Monday", etc.
 451      * @param newWeekdays the new weekday strings. The array should
 452      * be indexed by <code>Calendar.SUNDAY</code>,
 453      * <code>Calendar.MONDAY</code>, etc.
 454      */
 455     public void setWeekdays(String[] newWeekdays) {
 456         weekdays = Arrays.copyOf(newWeekdays, newWeekdays.length);
 457         cachedHashCode = 0;
 458     }
 459 
 460     /**
 461      * Gets short weekday strings. For example: "Sun", "Mon", etc.
 462      * @return the short weekday strings. Use <code>Calendar.SUNDAY</code>,
 463      * <code>Calendar.MONDAY</code>, etc. to index the result array.
 464      */
 465     public String[] getShortWeekdays() {
 466         return Arrays.copyOf(shortWeekdays, shortWeekdays.length);
 467     }
 468 
 469     /**
 470      * Sets short weekday strings. For example: "Sun", "Mon", etc.
 471      * @param newShortWeekdays the new short weekday strings. The array should
 472      * be indexed by <code>Calendar.SUNDAY</code>,
 473      * <code>Calendar.MONDAY</code>, etc.
 474      */
 475     public void setShortWeekdays(String[] newShortWeekdays) {
 476         shortWeekdays = Arrays.copyOf(newShortWeekdays, newShortWeekdays.length);
 477         cachedHashCode = 0;
 478     }
 479 
 480     /**
 481      * Gets ampm strings. For example: "AM" and "PM".
 482      * @return the ampm strings.
 483      */
 484     public String[] getAmPmStrings() {
 485         return Arrays.copyOf(ampms, ampms.length);
 486     }
 487 
 488     /**
 489      * Sets ampm strings. For example: "AM" and "PM".
 490      * @param newAmpms the new ampm strings.
 491      */
 492     public void setAmPmStrings(String[] newAmpms) {
 493         ampms = Arrays.copyOf(newAmpms, newAmpms.length);
 494         cachedHashCode = 0;
 495     }
 496 
 497     /**
 498      * Gets time zone strings.  Use of this method is discouraged; use
 499      * {@link java.util.TimeZone#getDisplayName() TimeZone.getDisplayName()}
 500      * instead.
 501      * <p>
 502      * The value returned is a
 503      * two-dimensional array of strings of size <em>n</em> by <em>m</em>,
 504      * where <em>m</em> is at least 5.  Each of the <em>n</em> rows is an
 505      * entry containing the localized names for a single <code>TimeZone</code>.
 506      * Each such row contains (with <code>i</code> ranging from
 507      * 0..<em>n</em>-1):
 508      * <ul>
 509      * <li><code>zoneStrings[i][0]</code> - time zone ID</li>
 510      * <li><code>zoneStrings[i][1]</code> - long name of zone in standard
 511      * time</li>
 512      * <li><code>zoneStrings[i][2]</code> - short name of zone in
 513      * standard time</li>
 514      * <li><code>zoneStrings[i][3]</code> - long name of zone in daylight
 515      * saving time</li>
 516      * <li><code>zoneStrings[i][4]</code> - short name of zone in daylight
 517      * saving time</li>
 518      * </ul>
 519      * The zone ID is <em>not</em> localized; it's one of the valid IDs of
 520      * the {@link java.util.TimeZone TimeZone} class that are not
 521      * <a href="../util/TimeZone.html#CustomID">custom IDs</a>.
 522      * All other entries are localized names.  If a zone does not implement
 523      * daylight saving time, the daylight saving time names should not be used.
 524      * <p>
 525      * If {@link #setZoneStrings(String[][]) setZoneStrings} has been called
 526      * on this <code>DateFormatSymbols</code> instance, then the strings
 527      * provided by that call are returned. Otherwise, the returned array
 528      * contains names provided by the Java runtime and by installed
 529      * {@link java.util.spi.TimeZoneNameProvider TimeZoneNameProvider}
 530      * implementations.
 531      *
 532      * @return the time zone strings.
 533      * @see #setZoneStrings(String[][])
 534      */
 535     public String[][] getZoneStrings() {
 536         return getZoneStringsImpl(true);
 537     }
 538 
 539     /**
 540      * Sets time zone strings.  The argument must be a
 541      * two-dimensional array of strings of size <em>n</em> by <em>m</em>,
 542      * where <em>m</em> is at least 5.  Each of the <em>n</em> rows is an
 543      * entry containing the localized names for a single <code>TimeZone</code>.
 544      * Each such row contains (with <code>i</code> ranging from
 545      * 0..<em>n</em>-1):
 546      * <ul>
 547      * <li><code>zoneStrings[i][0]</code> - time zone ID</li>
 548      * <li><code>zoneStrings[i][1]</code> - long name of zone in standard
 549      * time</li>
 550      * <li><code>zoneStrings[i][2]</code> - short name of zone in
 551      * standard time</li>
 552      * <li><code>zoneStrings[i][3]</code> - long name of zone in daylight
 553      * saving time</li>
 554      * <li><code>zoneStrings[i][4]</code> - short name of zone in daylight
 555      * saving time</li>
 556      * </ul>
 557      * The zone ID is <em>not</em> localized; it's one of the valid IDs of
 558      * the {@link java.util.TimeZone TimeZone} class that are not
 559      * <a href="../util/TimeZone.html#CustomID">custom IDs</a>.
 560      * All other entries are localized names.
 561      *
 562      * @param newZoneStrings the new time zone strings.
 563      * @exception IllegalArgumentException if the length of any row in
 564      *    <code>newZoneStrings</code> is less than 5
 565      * @exception NullPointerException if <code>newZoneStrings</code> is null
 566      * @see #getZoneStrings()
 567      */
 568     public void setZoneStrings(String[][] newZoneStrings) {
 569         String[][] aCopy = new String[newZoneStrings.length][];
 570         for (int i = 0; i < newZoneStrings.length; ++i) {
 571             int len = newZoneStrings[i].length;
 572             if (len < 5) {
 573                 throw new IllegalArgumentException();
 574             }
 575             aCopy[i] = Arrays.copyOf(newZoneStrings[i], len);
 576         }
 577         zoneStrings = aCopy;
 578         isZoneStringsSet = true;
 579         cachedHashCode = 0;
 580     }
 581 
 582     /**
 583      * Gets localized date-time pattern characters. For example: 'u', 't', etc.
 584      * @return the localized date-time pattern characters.
 585      */
 586     public String getLocalPatternChars() {
 587         return localPatternChars;
 588     }
 589 
 590     /**
 591      * Sets localized date-time pattern characters. For example: 'u', 't', etc.
 592      * @param newLocalPatternChars the new localized date-time
 593      * pattern characters.
 594      */
 595     public void setLocalPatternChars(String newLocalPatternChars) {
 596         // Call toString() to throw an NPE in case the argument is null
 597         localPatternChars = newLocalPatternChars.toString();
 598         cachedHashCode = 0;
 599     }
 600 
 601     /**
 602      * Overrides Cloneable
 603      */
 604     public Object clone()
 605     {
 606         try
 607         {
 608             DateFormatSymbols other = (DateFormatSymbols)super.clone();
 609             copyMembers(new SymbolsCacheEntry(locale), other);
 610             return other;
 611         } catch (CloneNotSupportedException e) {
 612             throw new InternalError(e);
 613         }
 614     }
 615 
 616     /**
 617      * Override hashCode.
 618      * Generates a hash code for the DateFormatSymbols object.
 619      */
 620     @Override
 621     public int hashCode() {
 622         int hashCode = cachedHashCode;
 623         if (hashCode == 0) {
 624             hashCode = 5;
 625             hashCode = 11 * hashCode + Arrays.hashCode(eras);
 626             hashCode = 11 * hashCode + Arrays.hashCode(months);
 627             hashCode = 11 * hashCode + Arrays.hashCode(shortMonths);
 628             hashCode = 11 * hashCode + Arrays.hashCode(weekdays);
 629             hashCode = 11 * hashCode + Arrays.hashCode(shortWeekdays);
 630             hashCode = 11 * hashCode + Arrays.hashCode(ampms);
 631             hashCode = 11 * hashCode + Arrays.deepHashCode(getZoneStringsWrapper());
 632             hashCode = 11 * hashCode + Objects.hashCode(localPatternChars);
 633             if (hashCode != 0) {
 634                 cachedHashCode = hashCode;
 635             }
 636         }
 637 
 638         return hashCode;
 639     }
 640 
 641     /**
 642      * Override equals
 643      */
 644     public boolean equals(Object obj)
 645     {
 646         if (this == obj) return true;
 647         if (obj == null || getClass() != obj.getClass()) return false;
 648         DateFormatSymbols that = (DateFormatSymbols) obj;
 649         return (Arrays.equals(eras, that.eras)
 650                 && Arrays.equals(months, that.months)
 651                 && Arrays.equals(shortMonths, that.shortMonths)
 652                 && Arrays.equals(weekdays, that.weekdays)
 653                 && Arrays.equals(shortWeekdays, that.shortWeekdays)
 654                 && Arrays.equals(ampms, that.ampms)
 655                 && Arrays.deepEquals(getZoneStringsWrapper(), that.getZoneStringsWrapper())
 656                 && ((localPatternChars != null
 657                   && localPatternChars.equals(that.localPatternChars))
 658                  || (localPatternChars == null
 659                   && that.localPatternChars == null)));
 660     }
 661 
 662     // =======================privates===============================
 663 
 664     /**
 665      * Useful constant for defining time zone offsets.
 666      */
 667     static final int millisPerHour = 60*60*1000;
 668 
 669     /**
 670      * Cache to hold DateFormatSymbols instances per Locale.
 671      */
 672     private static final ConcurrentMap<Locale, SoftReference<SymbolsCacheEntry>> cachedInstances
 673         = new ConcurrentHashMap<>(3);
 674 
 675     private transient int lastZoneIndex;
 676 
 677     /**
 678      * Cached hash code
 679      */
 680     transient volatile int cachedHashCode;
 681 
 682     private void initializeData(Locale desiredLocale) {
 683         locale = desiredLocale;
 684 
 685         // Copy values of a cached instance if any.
 686         SoftReference<SymbolsCacheEntry> ref = cachedInstances.get(locale);
 687         SymbolsCacheEntry sce;
 688         if (ref != null && (sce = ref.get()) != null) {
 689             copyMembers(sce, this);
 690             return;
 691         }
 692 
 693         // Initialize the fields from the ResourceBundle for locale.
 694         LocaleProviderAdapter adapter = LocaleProviderAdapter.getAdapter(DateFormatSymbolsProvider.class, locale);
 695         // Avoid any potential recursions
 696         if (!(adapter instanceof ResourceBundleBasedAdapter)) {
 697             adapter = LocaleProviderAdapter.getResourceBundleBased();
 698         }
 699         ResourceBundle resource = ((ResourceBundleBasedAdapter)adapter).getLocaleData().getDateFormatData(locale);
 700 
 701         // JRE and CLDR use different keys
 702         // JRE: Eras, short.Eras and narrow.Eras
 703         // CLDR: long.Eras, Eras and narrow.Eras
 704         if (resource.containsKey("Eras")) {
 705             eras = resource.getStringArray("Eras");
 706         } else if (resource.containsKey("long.Eras")) {
 707             eras = resource.getStringArray("long.Eras");
 708         } else if (resource.containsKey("short.Eras")) {
 709             eras = resource.getStringArray("short.Eras");
 710         }
 711         months = resource.getStringArray("MonthNames");
 712         shortMonths = resource.getStringArray("MonthAbbreviations");
 713         ampms = resource.getStringArray("AmPmMarkers");
 714         localPatternChars = resource.getString("DateTimePatternChars");
 715 
 716         // Day of week names are stored in a 1-based array.
 717         weekdays = toOneBasedArray(resource.getStringArray("DayNames"));
 718         shortWeekdays = toOneBasedArray(resource.getStringArray("DayAbbreviations"));
 719 
 720         sce = new SymbolsCacheEntry(locale);
 721         ref = new SoftReference<>(sce);
 722         SoftReference<SymbolsCacheEntry> x = cachedInstances.putIfAbsent(locale, ref);
 723         if (x != null) {
 724             SymbolsCacheEntry y = x.get();
 725             if (y == null) {
 726                 // Replace the empty SoftReference with ref.
 727                 cachedInstances.put(locale, ref);
 728             }
 729         }
 730     }
 731 
 732     private static String[] toOneBasedArray(String[] src) {
 733         int len = src.length;
 734         String[] dst = new String[len + 1];
 735         dst[0] = "";
 736         for (int i = 0; i < len; i++) {
 737             dst[i + 1] = src[i];
 738         }
 739         return dst;
 740     }
 741 
 742     /**
 743      * Package private: used by SimpleDateFormat
 744      * Gets the index for the given time zone ID to obtain the time zone
 745      * strings for formatting. The time zone ID is just for programmatic
 746      * lookup. NOT LOCALIZED!!!
 747      * @param ID the given time zone ID.
 748      * @return the index of the given time zone ID.  Returns -1 if
 749      * the given time zone ID can't be located in the DateFormatSymbols object.
 750      * @see java.util.SimpleTimeZone
 751      */
 752     final int getZoneIndex(String ID) {
 753         String[][] zoneStrings = getZoneStringsWrapper();
 754 
 755         /*
 756          * getZoneIndex has been re-written for performance reasons. instead of
 757          * traversing the zoneStrings array every time, we cache the last used zone
 758          * index
 759          */
 760         if (lastZoneIndex < zoneStrings.length && ID.equals(zoneStrings[lastZoneIndex][0])) {
 761             return lastZoneIndex;
 762         }
 763 
 764         /* slow path, search entire list */
 765         for (int index = 0; index < zoneStrings.length; index++) {
 766             if (ID.equals(zoneStrings[index][0])) {
 767                 lastZoneIndex = index;
 768                 return index;
 769             }
 770         }
 771 
 772         return -1;
 773     }
 774 
 775     /**
 776      * Wrapper method to the getZoneStrings(), which is called from inside
 777      * the java.text package and not to mutate the returned arrays, so that
 778      * it does not need to create a defensive copy.
 779      */
 780     final String[][] getZoneStringsWrapper() {
 781         if (isSubclassObject()) {
 782             return getZoneStrings();
 783         } else {
 784             return getZoneStringsImpl(false);
 785         }
 786     }
 787 
 788     private String[][] getZoneStringsImpl(boolean needsCopy) {
 789         if (zoneStrings == null) {
 790             zoneStrings = TimeZoneNameUtility.getZoneStrings(locale);
 791         }
 792 
 793         if (!needsCopy) {
 794             return zoneStrings;
 795         }
 796 
 797         int len = zoneStrings.length;
 798         String[][] aCopy = new String[len][];
 799         for (int i = 0; i < len; i++) {
 800             aCopy[i] = Arrays.copyOf(zoneStrings[i], zoneStrings[i].length);
 801         }
 802         return aCopy;
 803     }
 804 
 805     private boolean isSubclassObject() {
 806         return !getClass().getName().equals("java.text.DateFormatSymbols");
 807     }
 808 
 809     /**
 810      * Clones all the data members from the source DateFormatSymbols to
 811      * the target DateFormatSymbols. This is only for subclasses.
 812      * @param src the source DateFormatSymbols.
 813      * @param dst the target DateFormatSymbols.
 814      */
 815     private void copyMembers(SymbolsCacheEntry src, DateFormatSymbols dst)
 816     {
 817         dst.eras = Arrays.copyOf(src.eras, src.eras.length);
 818         dst.months = Arrays.copyOf(src.months, src.months.length);
 819         dst.shortMonths = Arrays.copyOf(src.shortMonths, src.shortMonths.length);
 820         dst.weekdays = Arrays.copyOf(src.weekdays, src.weekdays.length);
 821         dst.shortWeekdays = Arrays.copyOf(src.shortWeekdays, src.shortWeekdays.length);
 822         dst.ampms = Arrays.copyOf(src.ampms, src.ampms.length);
 823         if (src.zoneStrings != null) {
 824             dst.zoneStrings = getZoneStringsImpl(true);
 825         } else {
 826             dst.zoneStrings = null;
 827         }
 828         dst.localPatternChars = src.localPatternChars;
 829         dst.cachedHashCode = 0;
 830     }
 831 
 832     /**
 833      * Write out the default serializable data, after ensuring the
 834      * <code>zoneStrings</code> field is initialized in order to make
 835      * sure the backward compatibility.
 836      *
 837      * @since 1.6
 838      */
 839     private void writeObject(ObjectOutputStream stream) throws IOException {
 840         if (zoneStrings == null) {
 841             zoneStrings = TimeZoneNameUtility.getZoneStrings(locale);
 842         }
 843         stream.defaultWriteObject();
 844     }
 845 
 846     private static class SymbolsCacheEntry {
 847 
 848         final String eras[];
 849         final String months[];
 850         final String shortMonths[];
 851         final String weekdays[];
 852         final String shortWeekdays[];
 853         final String ampms[];
 854         final String zoneStrings[][];
 855         final String localPatternChars;
 856 
 857         SymbolsCacheEntry(Locale locale) {
 858             // Initialize the fields from the ResourceBundle for locale.
 859             LocaleProviderAdapter adapter = LocaleProviderAdapter.getAdapter(DateFormatSymbolsProvider.class, locale);
 860             // Avoid any potential recursions
 861             if (!(adapter instanceof ResourceBundleBasedAdapter)) {
 862                 adapter = LocaleProviderAdapter.getResourceBundleBased();
 863             }
 864             ResourceBundle resource = ((ResourceBundleBasedAdapter) adapter).getLocaleData().getDateFormatData(locale);
 865             if (resource.containsKey("Eras")) {
 866                 this.eras = resource.getStringArray("Eras");
 867             } else if (resource.containsKey("long.Eras")) {
 868                 this.eras = resource.getStringArray("long.Eras");
 869             } else if (resource.containsKey("short.Eras")) {
 870                 this.eras = resource.getStringArray("short.Eras");
 871             } else {
 872                 this.eras = null;
 873             }
 874             this.months = resource.getStringArray("MonthNames");
 875             this.shortMonths = resource.getStringArray("MonthAbbreviations");
 876             this.weekdays = toOneBasedArray(resource.getStringArray("DayNames"));
 877             this.shortWeekdays = toOneBasedArray(resource.getStringArray("DayAbbreviations"));
 878             this.ampms = resource.getStringArray("AmPmMarkers");
 879             this.zoneStrings = TimeZoneNameUtility.getZoneStrings(locale);
 880             this.localPatternChars = resource.getString("DateTimePatternChars");
 881 
 882         }
 883     }
 884 }