1 /*
   2  * Copyright (c) 1996, 2012, Oracle and/or its affiliates. All rights reserved.
   3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   4  *
   5  * This code is free software; you can redistribute it and/or modify it
   6  * under the terms of the GNU General Public License version 2 only, as
   7  * published by the Free Software Foundation.  Oracle designates this
   8  * particular file as subject to the "Classpath" exception as provided
   9  * by Oracle in the LICENSE file that accompanied this code.
  10  *
  11  * This code is distributed in the hope that it will be useful, but WITHOUT
  12  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  13  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  14  * version 2 for more details (a copy is included in the LICENSE file that
  15  * accompanied this code).
  16  *
  17  * You should have received a copy of the GNU General Public License version
  18  * 2 along with this work; if not, write to the Free Software Foundation,
  19  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  20  *
  21  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  22  * or visit www.oracle.com if you need additional information or have any
  23  * questions.
  24  */
  25 
  26 /*
  27  * (C) Copyright Taligent, Inc. 1996 - All Rights Reserved
  28  * (C) Copyright IBM Corp. 1996 - All Rights Reserved
  29  *
  30  *   The original version of this source code and documentation is copyrighted
  31  * and owned by Taligent, Inc., a wholly-owned subsidiary of IBM. These
  32  * materials are provided under terms of a License Agreement between Taligent
  33  * and Sun. This technology is protected by multiple US and International
  34  * patents. This notice and attribution to Taligent may not be removed.
  35  *   Taligent is a registered trademark of Taligent, Inc.
  36  *
  37  */
  38 
  39 package java.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.ResourceBundle;
  49 import java.util.TimeZone;
  50 import java.util.concurrent.ConcurrentHashMap;
  51 import java.util.concurrent.ConcurrentMap;
  52 import sun.util.locale.provider.LocaleProviderAdapter;
  53 import sun.util.locale.provider.LocaleServiceProviderPool;
  54 import sun.util.locale.provider.TimeZoneNameUtility;
  55 import sun.util.resources.LocaleData;
  56 
  57 /**
  58  * <code>DateFormatSymbols</code> is a public class for encapsulating
  59  * localizable date-time formatting data, such as the names of the
  60  * months, the names of the days of the week, and the time zone data.
  61  * <code>DateFormat</code> and <code>SimpleDateFormat</code> both use
  62  * <code>DateFormatSymbols</code> to encapsulate this information.
  63  *
  64  * <p>
  65  * Typically you shouldn't use <code>DateFormatSymbols</code> directly.
  66  * Rather, you are encouraged to create a date-time formatter with the
  67  * <code>DateFormat</code> class's factory methods: <code>getTimeInstance</code>,
  68  * <code>getDateInstance</code>, or <code>getDateTimeInstance</code>.
  69  * These methods automatically create a <code>DateFormatSymbols</code> for
  70  * the formatter so that you don't have to. After the
  71  * formatter is created, you may modify its format pattern using the
  72  * <code>setPattern</code> method. For more information about
  73  * creating formatters using <code>DateFormat</code>'s factory methods,
  74  * see {@link DateFormat}.
  75  *
  76  * <p>
  77  * If you decide to create a date-time formatter with a specific
  78  * format pattern for a specific locale, you can do so with:
  79  * <blockquote>
  80  * <pre>
  81  * new SimpleDateFormat(aPattern, DateFormatSymbols.getInstance(aLocale)).
  82  * </pre>
  83  * </blockquote>
  84  *
  85  * <p>
  86  * <code>DateFormatSymbols</code> objects are cloneable. When you obtain
  87  * a <code>DateFormatSymbols</code> object, feel free to modify the
  88  * date-time formatting data. For instance, you can replace the localized
  89  * date-time format pattern characters with the ones that you feel easy
  90  * to remember. Or you can change the representative cities
  91  * to your favorite ones.
  92  *
  93  * <p>
  94  * New <code>DateFormatSymbols</code> subclasses may be added to support
  95  * <code>SimpleDateFormat</code> for date-time formatting for additional locales.
  96 
  97  * @see          DateFormat
  98  * @see          SimpleDateFormat
  99  * @see          java.util.SimpleTimeZone
 100  * @author       Chen-Lieh Huang
 101  */
 102 public class DateFormatSymbols implements Serializable, Cloneable {
 103 
 104     /**
 105      * Construct a DateFormatSymbols object by loading format data from
 106      * resources for the default locale. This constructor can only
 107      * construct instances for the locales supported by the Java
 108      * runtime environment, not for those supported by installed
 109      * {@link java.text.spi.DateFormatSymbolsProvider DateFormatSymbolsProvider}
 110      * implementations. For full locale coverage, use the
 111      * {@link #getInstance(Locale) getInstance} method.
 112      *
 113      * @see #getInstance()
 114      * @exception  java.util.MissingResourceException
 115      *             if the resources for the default locale cannot be
 116      *             found or cannot be loaded.
 117      */
 118     public DateFormatSymbols()
 119     {
 120         initializeData(Locale.getDefault(Locale.Category.FORMAT));
 121     }
 122 
 123     /**
 124      * Construct a DateFormatSymbols object by loading format data from
 125      * resources for the given locale. This constructor can only
 126      * construct instances for the locales supported by the Java
 127      * runtime environment, not for those supported by installed
 128      * {@link java.text.spi.DateFormatSymbolsProvider DateFormatSymbolsProvider}
 129      * implementations. For full locale coverage, use the
 130      * {@link #getInstance(Locale) getInstance} method.
 131      *
 132      * @see #getInstance(Locale)
 133      * @exception  java.util.MissingResourceException
 134      *             if the resources for the specified locale cannot be
 135      *             found or cannot be loaded.
 136      */
 137     public DateFormatSymbols(Locale locale)
 138     {
 139         initializeData(locale);
 140     }
 141 
 142     /**
 143      * Era strings. For example: "AD" and "BC".  An array of 2 strings,
 144      * indexed by <code>Calendar.BC</code> and <code>Calendar.AD</code>.
 145      * @serial
 146      */
 147     String eras[] = null;
 148 
 149     /**
 150      * Month strings. For example: "January", "February", etc.  An array
 151      * of 13 strings (some calendars have 13 months), indexed by
 152      * <code>Calendar.JANUARY</code>, <code>Calendar.FEBRUARY</code>, etc.
 153      * @serial
 154      */
 155     String months[] = null;
 156 
 157     /**
 158      * Short month strings. For example: "Jan", "Feb", etc.  An array of
 159      * 13 strings (some calendars have 13 months), indexed by
 160      * <code>Calendar.JANUARY</code>, <code>Calendar.FEBRUARY</code>, etc.
 161 
 162      * @serial
 163      */
 164     String shortMonths[] = null;
 165 
 166     /**
 167      * Weekday strings. For example: "Sunday", "Monday", etc.  An array
 168      * of 8 strings, indexed by <code>Calendar.SUNDAY</code>,
 169      * <code>Calendar.MONDAY</code>, etc.
 170      * The element <code>weekdays[0]</code> is ignored.
 171      * @serial
 172      */
 173     String weekdays[] = null;
 174 
 175     /**
 176      * Short weekday strings. For example: "Sun", "Mon", etc.  An array
 177      * of 8 strings, indexed by <code>Calendar.SUNDAY</code>,
 178      * <code>Calendar.MONDAY</code>, etc.
 179      * The element <code>shortWeekdays[0]</code> is ignored.
 180      * @serial
 181      */
 182     String shortWeekdays[] = null;
 183 
 184     /**
 185      * AM and PM strings. For example: "AM" and "PM".  An array of
 186      * 2 strings, indexed by <code>Calendar.AM</code> and
 187      * <code>Calendar.PM</code>.
 188      * @serial
 189      */
 190     String ampms[] = null;
 191 
 192     /**
 193      * Localized names of time zones in this locale.  This is a
 194      * two-dimensional array of strings of size <em>n</em> by <em>m</em>,
 195      * where <em>m</em> is at least 5.  Each of the <em>n</em> rows is an
 196      * entry containing the localized names for a single <code>TimeZone</code>.
 197      * Each such row contains (with <code>i</code> ranging from
 198      * 0..<em>n</em>-1):
 199      * <ul>
 200      * <li><code>zoneStrings[i][0]</code> - time zone ID</li>
 201      * <li><code>zoneStrings[i][1]</code> - long name of zone in standard
 202      * time</li>
 203      * <li><code>zoneStrings[i][2]</code> - short name of zone in
 204      * standard time</li>
 205      * <li><code>zoneStrings[i][3]</code> - long name of zone in daylight
 206      * saving time</li>
 207      * <li><code>zoneStrings[i][4]</code> - short name of zone in daylight
 208      * saving time</li>
 209      * </ul>
 210      * The zone ID is <em>not</em> localized; it's one of the valid IDs of
 211      * the {@link java.util.TimeZone TimeZone} class that are not
 212      * <a href="../java/util/TimeZone.html#CustomID">custom IDs</a>.
 213      * All other entries are localized names.
 214      * @see java.util.TimeZone
 215      * @serial
 216      */
 217     String zoneStrings[][] = null;
 218 
 219     /**
 220      * Indicates that zoneStrings is set externally with setZoneStrings() method.
 221      */
 222     transient boolean isZoneStringsSet = false;
 223 
 224     /**
 225      * Unlocalized date-time pattern characters. For example: 'y', 'd', etc.
 226      * All locales use the same these unlocalized pattern characters.
 227      */
 228     static final String  patternChars = "GyMdkHmsSEDFwWahKzZYuXL";
 229 
 230     static final int PATTERN_ERA                  =  0; // G
 231     static final int PATTERN_YEAR                 =  1; // y
 232     static final int PATTERN_MONTH                =  2; // M
 233     static final int PATTERN_DAY_OF_MONTH         =  3; // d
 234     static final int PATTERN_HOUR_OF_DAY1         =  4; // k
 235     static final int PATTERN_HOUR_OF_DAY0         =  5; // H
 236     static final int PATTERN_MINUTE               =  6; // m
 237     static final int PATTERN_SECOND               =  7; // s
 238     static final int PATTERN_MILLISECOND          =  8; // S
 239     static final int PATTERN_DAY_OF_WEEK          =  9; // E
 240     static final int PATTERN_DAY_OF_YEAR          = 10; // D
 241     static final int PATTERN_DAY_OF_WEEK_IN_MONTH = 11; // F
 242     static final int PATTERN_WEEK_OF_YEAR         = 12; // w
 243     static final int PATTERN_WEEK_OF_MONTH        = 13; // W
 244     static final int PATTERN_AM_PM                = 14; // a
 245     static final int PATTERN_HOUR1                = 15; // h
 246     static final int PATTERN_HOUR0                = 16; // K
 247     static final int PATTERN_ZONE_NAME            = 17; // z
 248     static final int PATTERN_ZONE_VALUE           = 18; // Z
 249     static final int PATTERN_WEEK_YEAR            = 19; // Y
 250     static final int PATTERN_ISO_DAY_OF_WEEK      = 20; // u
 251     static final int PATTERN_ISO_ZONE             = 21; // X
 252     static final int PATTERN_MONTH_STANDALONE     = 22; // L
 253 
 254     /**
 255      * Localized date-time pattern characters. For example, a locale may
 256      * wish to use 'u' rather than 'y' to represent years in its date format
 257      * pattern strings.
 258      * This string must be exactly 18 characters long, with the index of
 259      * the characters described by <code>DateFormat.ERA_FIELD</code>,
 260      * <code>DateFormat.YEAR_FIELD</code>, etc.  Thus, if the string were
 261      * "Xz...", then localized patterns would use 'X' for era and 'z' for year.
 262      * @serial
 263      */
 264     String  localPatternChars = null;
 265 
 266     /**
 267      * The locale which is used for initializing this DateFormatSymbols object.
 268      *
 269      * @since 1.6
 270      * @serial
 271      */
 272     Locale locale = null;
 273 
 274     /* use serialVersionUID from JDK 1.1.4 for interoperability */
 275     static final long serialVersionUID = -5987973545549424702L;
 276 
 277     /**
 278      * Returns an array of all locales for which the
 279      * <code>getInstance</code> methods of this class can return
 280      * localized instances.
 281      * The returned array represents the union of locales supported by the
 282      * Java runtime and by installed
 283      * {@link java.text.spi.DateFormatSymbolsProvider DateFormatSymbolsProvider}
 284      * implementations.  It must contain at least a <code>Locale</code>
 285      * instance equal to {@link java.util.Locale#US Locale.US}.
 286      *
 287      * @return An array of locales for which localized
 288      *         <code>DateFormatSymbols</code> instances are available.
 289      * @since 1.6
 290      */
 291     public static Locale[] getAvailableLocales() {
 292         LocaleServiceProviderPool pool=
 293             LocaleServiceProviderPool.getPool(DateFormatSymbolsProvider.class);
 294         return pool.getAvailableLocales();
 295     }
 296 
 297     /**
 298      * Gets the <code>DateFormatSymbols</code> instance for the default
 299      * locale.  This method provides access to <code>DateFormatSymbols</code>
 300      * instances for locales supported by the Java runtime itself as well
 301      * as for those supported by installed
 302      * {@link java.text.spi.DateFormatSymbolsProvider DateFormatSymbolsProvider}
 303      * implementations.
 304      * @return a <code>DateFormatSymbols</code> instance.
 305      * @since 1.6
 306      */
 307     public static final DateFormatSymbols getInstance() {
 308         return getInstance(Locale.getDefault(Locale.Category.FORMAT));
 309     }
 310 
 311     /**
 312      * Gets the <code>DateFormatSymbols</code> instance for the specified
 313      * locale.  This method provides access to <code>DateFormatSymbols</code>
 314      * instances for locales supported by the Java runtime itself as well
 315      * as for those supported by installed
 316      * {@link java.text.spi.DateFormatSymbolsProvider DateFormatSymbolsProvider}
 317      * implementations.
 318      * @param locale the given locale.
 319      * @return a <code>DateFormatSymbols</code> instance.
 320      * @exception NullPointerException if <code>locale</code> is null
 321      * @since 1.6
 322      */
 323     public static final DateFormatSymbols getInstance(Locale locale) {
 324         DateFormatSymbols dfs = getProviderInstance(locale);
 325         if (dfs != null) {
 326             return dfs;
 327         }
 328         throw new RuntimeException("DateFormatSymbols instance creation failed.");
 329     }
 330 
 331     /**
 332      * Returns a DateFormatSymbols provided by a provider or found in
 333      * the cache. Note that this method returns a cached instance,
 334      * not its clone. Therefore, the instance should never be given to
 335      * an application.
 336      */
 337     static final DateFormatSymbols getInstanceRef(Locale locale) {
 338         DateFormatSymbols dfs = getProviderInstance(locale);
 339         if (dfs != null) {
 340             return dfs;
 341         }
 342         throw new RuntimeException("DateFormatSymbols instance creation failed.");
 343     }
 344 
 345     private static DateFormatSymbols getProviderInstance(Locale locale) {
 346         LocaleProviderAdapter adapter = LocaleProviderAdapter.getAdapter(DateFormatSymbolsProvider.class, locale);
 347         DateFormatSymbolsProvider provider = adapter.getDateFormatSymbolsProvider();
 348         return provider.getInstance(locale);
 349     }
 350 
 351     /**
 352      * Gets era strings. For example: "AD" and "BC".
 353      * @return the era strings.
 354      */
 355     public String[] getEras() {
 356         return Arrays.copyOf(eras, eras.length);
 357     }
 358 
 359     /**
 360      * Sets era strings. For example: "AD" and "BC".
 361      * @param newEras the new era strings.
 362      */
 363     public void setEras(String[] newEras) {
 364         eras = Arrays.copyOf(newEras, newEras.length);
 365     }
 366 
 367     /**
 368      * Gets month strings. For example: "January", "February", etc.
 369      *
 370      * <p>If the language requires different forms for formatting and
 371      * stand-alone usages, this method returns month names in the
 372      * formatting form. For example, the preferred month name for
 373      * January in the Czech language is <em>ledna</em> in the
 374      * formatting form, while it is <em>leden</em> in the stand-alone
 375      * form. This method returns {@code "ledna"} in this case. Refer
 376      * to the <a href="http://unicode.org/reports/tr35/#Calendar_Elements">
 377      * Calendar Elements in the Unicode Locale Data Markup Language
 378      * (LDML) specification</a> for more details.
 379      *
 380      * @return the month strings.
 381      */
 382     public String[] getMonths() {
 383         return Arrays.copyOf(months, months.length);
 384     }
 385 
 386     /**
 387      * Sets month strings. For example: "January", "February", etc.
 388      * @param newMonths the new month strings.
 389      */
 390     public void setMonths(String[] newMonths) {
 391         months = Arrays.copyOf(newMonths, newMonths.length);
 392     }
 393 
 394     /**
 395      * Gets short month strings. For example: "Jan", "Feb", etc.
 396      *
 397      * <p>If the language requires different forms for formatting and
 398      * stand-alone usages, This method returns short month names in
 399      * the formatting form. For example, the preferred abbreviation
 400      * for January in the Catalan language is <em>de gen.</em> in the
 401      * formatting form, while it is <em>gen.</em> in the stand-alone
 402      * form. This method returns {@code "de gen."} in this case. Refer
 403      * to the <a href="http://unicode.org/reports/tr35/#Calendar_Elements">
 404      * Calendar Elements in the Unicode Locale Data Markup Language
 405      * (LDML) specification</a> for more details.
 406      *
 407      * @return the short month strings.
 408      */
 409     public String[] getShortMonths() {
 410         return Arrays.copyOf(shortMonths, shortMonths.length);
 411     }
 412 
 413     /**
 414      * Sets short month strings. For example: "Jan", "Feb", etc.
 415      * @param newShortMonths the new short month strings.
 416      */
 417     public void setShortMonths(String[] newShortMonths) {
 418         shortMonths = Arrays.copyOf(newShortMonths, newShortMonths.length);
 419     }
 420 
 421     /**
 422      * Gets weekday strings. For example: "Sunday", "Monday", etc.
 423      * @return the weekday strings. Use <code>Calendar.SUNDAY</code>,
 424      * <code>Calendar.MONDAY</code>, etc. to index the result array.
 425      */
 426     public String[] getWeekdays() {
 427         return Arrays.copyOf(weekdays, weekdays.length);
 428     }
 429 
 430     /**
 431      * Sets weekday strings. For example: "Sunday", "Monday", etc.
 432      * @param newWeekdays the new weekday strings. The array should
 433      * be indexed by <code>Calendar.SUNDAY</code>,
 434      * <code>Calendar.MONDAY</code>, etc.
 435      */
 436     public void setWeekdays(String[] newWeekdays) {
 437         weekdays = Arrays.copyOf(newWeekdays, newWeekdays.length);
 438     }
 439 
 440     /**
 441      * Gets short weekday strings. For example: "Sun", "Mon", etc.
 442      * @return the short weekday strings. Use <code>Calendar.SUNDAY</code>,
 443      * <code>Calendar.MONDAY</code>, etc. to index the result array.
 444      */
 445     public String[] getShortWeekdays() {
 446         return Arrays.copyOf(shortWeekdays, shortWeekdays.length);
 447     }
 448 
 449     /**
 450      * Sets short weekday strings. For example: "Sun", "Mon", etc.
 451      * @param newShortWeekdays the new short weekday strings. The array should
 452      * be indexed by <code>Calendar.SUNDAY</code>,
 453      * <code>Calendar.MONDAY</code>, etc.
 454      */
 455     public void setShortWeekdays(String[] newShortWeekdays) {
 456         shortWeekdays = Arrays.copyOf(newShortWeekdays, newShortWeekdays.length);
 457     }
 458 
 459     /**
 460      * Gets ampm strings. For example: "AM" and "PM".
 461      * @return the ampm strings.
 462      */
 463     public String[] getAmPmStrings() {
 464         return Arrays.copyOf(ampms, ampms.length);
 465     }
 466 
 467     /**
 468      * Sets ampm strings. For example: "AM" and "PM".
 469      * @param newAmpms the new ampm strings.
 470      */
 471     public void setAmPmStrings(String[] newAmpms) {
 472         ampms = Arrays.copyOf(newAmpms, newAmpms.length);
 473     }
 474 
 475     /**
 476      * Gets time zone strings.  Use of this method is discouraged; use
 477      * {@link java.util.TimeZone#getDisplayName() TimeZone.getDisplayName()}
 478      * instead.
 479      * <p>
 480      * The value returned is a
 481      * two-dimensional array of strings of size <em>n</em> by <em>m</em>,
 482      * where <em>m</em> is at least 5.  Each of the <em>n</em> rows is an
 483      * entry containing the localized names for a single <code>TimeZone</code>.
 484      * Each such row contains (with <code>i</code> ranging from
 485      * 0..<em>n</em>-1):
 486      * <ul>
 487      * <li><code>zoneStrings[i][0]</code> - time zone ID</li>
 488      * <li><code>zoneStrings[i][1]</code> - long name of zone in standard
 489      * time</li>
 490      * <li><code>zoneStrings[i][2]</code> - short name of zone in
 491      * standard time</li>
 492      * <li><code>zoneStrings[i][3]</code> - long name of zone in daylight
 493      * saving time</li>
 494      * <li><code>zoneStrings[i][4]</code> - short name of zone in daylight
 495      * saving time</li>
 496      * </ul>
 497      * The zone ID is <em>not</em> localized; it's one of the valid IDs of
 498      * the {@link java.util.TimeZone TimeZone} class that are not
 499      * <a href="../util/TimeZone.html#CustomID">custom IDs</a>.
 500      * All other entries are localized names.  If a zone does not implement
 501      * daylight saving time, the daylight saving time names should not be used.
 502      * <p>
 503      * If {@link #setZoneStrings(String[][]) setZoneStrings} has been called
 504      * on this <code>DateFormatSymbols</code> instance, then the strings
 505      * provided by that call are returned. Otherwise, the returned array
 506      * contains names provided by the Java runtime and by installed
 507      * {@link java.util.spi.TimeZoneNameProvider TimeZoneNameProvider}
 508      * implementations.
 509      *
 510      * @return the time zone strings.
 511      * @see #setZoneStrings(String[][])
 512      */
 513     public String[][] getZoneStrings() {
 514         return getZoneStringsImpl(true);
 515     }
 516 
 517     /**
 518      * Sets time zone strings.  The argument must be a
 519      * two-dimensional array of strings of size <em>n</em> by <em>m</em>,
 520      * where <em>m</em> is at least 5.  Each of the <em>n</em> rows is an
 521      * entry containing the localized names for a single <code>TimeZone</code>.
 522      * Each such row contains (with <code>i</code> ranging from
 523      * 0..<em>n</em>-1):
 524      * <ul>
 525      * <li><code>zoneStrings[i][0]</code> - time zone ID</li>
 526      * <li><code>zoneStrings[i][1]</code> - long name of zone in standard
 527      * time</li>
 528      * <li><code>zoneStrings[i][2]</code> - short name of zone in
 529      * standard time</li>
 530      * <li><code>zoneStrings[i][3]</code> - long name of zone in daylight
 531      * saving time</li>
 532      * <li><code>zoneStrings[i][4]</code> - short name of zone in daylight
 533      * saving time</li>
 534      * </ul>
 535      * The zone ID is <em>not</em> localized; it's one of the valid IDs of
 536      * the {@link java.util.TimeZone TimeZone} class that are not
 537      * <a href="../util/TimeZone.html#CustomID">custom IDs</a>.
 538      * All other entries are localized names.
 539      *
 540      * @param newZoneStrings the new time zone strings.
 541      * @exception IllegalArgumentException if the length of any row in
 542      *    <code>newZoneStrings</code> is less than 5
 543      * @exception NullPointerException if <code>newZoneStrings</code> is null
 544      * @see #getZoneStrings()
 545      */
 546     public void setZoneStrings(String[][] newZoneStrings) {
 547         String[][] aCopy = new String[newZoneStrings.length][];
 548         for (int i = 0; i < newZoneStrings.length; ++i) {
 549             int len = newZoneStrings[i].length;
 550             if (len < 5) {
 551                 throw new IllegalArgumentException();
 552             }
 553             aCopy[i] = Arrays.copyOf(newZoneStrings[i], len);
 554         }
 555         zoneStrings = aCopy;
 556         isZoneStringsSet = true;
 557     }
 558 
 559     /**
 560      * Gets localized date-time pattern characters. For example: 'u', 't', etc.
 561      * @return the localized date-time pattern characters.
 562      */
 563     public String getLocalPatternChars() {
 564         return localPatternChars;
 565     }
 566 
 567     /**
 568      * Sets localized date-time pattern characters. For example: 'u', 't', etc.
 569      * @param newLocalPatternChars the new localized date-time
 570      * pattern characters.
 571      */
 572     public void setLocalPatternChars(String newLocalPatternChars) {
 573         // Call toString() to throw an NPE in case the argument is null
 574         localPatternChars = newLocalPatternChars.toString();
 575     }
 576 
 577     /**
 578      * Overrides Cloneable
 579      */
 580     public Object clone()
 581     {
 582         try
 583         {
 584             DateFormatSymbols other = (DateFormatSymbols)super.clone();
 585             copyMembers(this, other);
 586             return other;
 587         } catch (CloneNotSupportedException e) {
 588             throw new InternalError(e);
 589         }
 590     }
 591 
 592     /**
 593      * Override hashCode.
 594      * Generates a hash code for the DateFormatSymbols object.
 595      */
 596     public int hashCode() {
 597         int hashcode = 0;
 598         String[][] zoneStrings = getZoneStringsWrapper();
 599         for (int index = 0; index < zoneStrings[0].length; ++index)
 600             hashcode ^= zoneStrings[0][index].hashCode();
 601         return hashcode;
 602     }
 603 
 604     /**
 605      * Override equals
 606      */
 607     public boolean equals(Object obj)
 608     {
 609         if (this == obj) return true;
 610         if (obj == null || getClass() != obj.getClass()) return false;
 611         DateFormatSymbols that = (DateFormatSymbols) obj;
 612         return (Arrays.equals(eras, that.eras)
 613                 && Arrays.equals(months, that.months)
 614                 && Arrays.equals(shortMonths, that.shortMonths)
 615                 && Arrays.equals(weekdays, that.weekdays)
 616                 && Arrays.equals(shortWeekdays, that.shortWeekdays)
 617                 && Arrays.equals(ampms, that.ampms)
 618                 && Arrays.deepEquals(getZoneStringsWrapper(), that.getZoneStringsWrapper())
 619                 && ((localPatternChars != null
 620                   && localPatternChars.equals(that.localPatternChars))
 621                  || (localPatternChars == null
 622                   && that.localPatternChars == null)));
 623     }
 624 
 625     // =======================privates===============================
 626 
 627     /**
 628      * Useful constant for defining time zone offsets.
 629      */
 630     static final int millisPerHour = 60*60*1000;
 631 
 632     /**
 633      * Cache to hold DateFormatSymbols instances per Locale.
 634      */
 635     private static final ConcurrentMap<Locale, SoftReference<DateFormatSymbols>> cachedInstances
 636         = new ConcurrentHashMap<>(3);
 637 
 638     private transient int lastZoneIndex = 0;
 639 
 640     private void initializeData(Locale desiredLocale) {
 641         locale = desiredLocale;
 642 
 643         // Copy values of a cached instance if any.
 644         SoftReference<DateFormatSymbols> ref = cachedInstances.get(locale);
 645         DateFormatSymbols dfs;
 646         if (ref != null && (dfs = ref.get()) != null) {
 647             copyMembers(dfs, this);
 648             return;
 649         }
 650 
 651         // Initialize the fields from the ResourceBundle for locale.
 652         LocaleProviderAdapter adapter = LocaleProviderAdapter.getAdapter(DateFormatSymbolsProvider.class, locale);
 653         // Avaoid any potential recursions
 654         switch (adapter.getAdapterType()) {
 655         case HOST:
 656         case SPI:
 657             adapter = LocaleProviderAdapter.getResourceBundleBased();
 658             break;
 659         }
 660         ResourceBundle resource = adapter.getLocaleData().getDateFormatData(locale);
 661 
 662         eras = resource.getStringArray("Eras");
 663         months = resource.getStringArray("MonthNames");
 664         shortMonths = resource.getStringArray("MonthAbbreviations");
 665         ampms = resource.getStringArray("AmPmMarkers");
 666         localPatternChars = resource.getString("DateTimePatternChars");
 667 
 668         // Day of week names are stored in a 1-based array.
 669         weekdays = toOneBasedArray(resource.getStringArray("DayNames"));
 670         shortWeekdays = toOneBasedArray(resource.getStringArray("DayAbbreviations"));
 671 
 672         // Put a clone in the cache
 673         ref = new SoftReference<>((DateFormatSymbols)this.clone());
 674         SoftReference<DateFormatSymbols> x = cachedInstances.putIfAbsent(locale, ref);
 675         if (x != null) {
 676             DateFormatSymbols y = x.get();
 677             if (y == null) {
 678                 // Replace the empty SoftReference with ref.
 679                 cachedInstances.put(locale, ref);
 680             }
 681         }
 682     }
 683 
 684     private static String[] toOneBasedArray(String[] src) {
 685         int len = src.length;
 686         String[] dst = new String[len + 1];
 687         dst[0] = "";
 688         for (int i = 0; i < len; i++) {
 689             dst[i + 1] = src[i];
 690         }
 691         return dst;
 692     }
 693 
 694     /**
 695      * Package private: used by SimpleDateFormat
 696      * Gets the index for the given time zone ID to obtain the time zone
 697      * strings for formatting. The time zone ID is just for programmatic
 698      * lookup. NOT LOCALIZED!!!
 699      * @param ID the given time zone ID.
 700      * @return the index of the given time zone ID.  Returns -1 if
 701      * the given time zone ID can't be located in the DateFormatSymbols object.
 702      * @see java.util.SimpleTimeZone
 703      */
 704     final int getZoneIndex(String ID) {
 705         String[][] zoneStrings = getZoneStringsWrapper();
 706 
 707         /*
 708          * getZoneIndex has been re-written for performance reasons. instead of
 709          * traversing the zoneStrings array every time, we cache the last used zone
 710          * index
 711          */
 712         if (lastZoneIndex < zoneStrings.length && ID.equals(zoneStrings[lastZoneIndex][0])) {
 713             return lastZoneIndex;
 714         }
 715 
 716         /* slow path, search entire list */
 717         for (int index = 0; index < zoneStrings.length; index++) {
 718             if (ID.equals(zoneStrings[index][0])) {
 719                 lastZoneIndex = index;
 720                 return index;
 721             }
 722         }
 723 
 724         return -1;
 725     }
 726 
 727     /**
 728      * Wrapper method to the getZoneStrings(), which is called from inside
 729      * the java.text package and not to mutate the returned arrays, so that
 730      * it does not need to create a defensive copy.
 731      */
 732     final String[][] getZoneStringsWrapper() {
 733         if (isSubclassObject()) {
 734             return getZoneStrings();
 735         } else {
 736             return getZoneStringsImpl(false);
 737         }
 738     }
 739 
 740     private String[][] getZoneStringsImpl(boolean needsCopy) {
 741         if (zoneStrings == null) {
 742             zoneStrings = TimeZoneNameUtility.getZoneStrings(locale);
 743         }
 744 
 745         if (!needsCopy) {
 746             return zoneStrings;
 747         }
 748 
 749         int len = zoneStrings.length;
 750         String[][] aCopy = new String[len][];
 751         for (int i = 0; i < len; i++) {
 752             aCopy[i] = Arrays.copyOf(zoneStrings[i], zoneStrings[i].length);
 753         }
 754         return aCopy;
 755     }
 756 
 757     private boolean isSubclassObject() {
 758         return !getClass().getName().equals("java.text.DateFormatSymbols");
 759     }
 760 
 761     /**
 762      * Clones all the data members from the source DateFormatSymbols to
 763      * the target DateFormatSymbols. This is only for subclasses.
 764      * @param src the source DateFormatSymbols.
 765      * @param dst the target DateFormatSymbols.
 766      */
 767     private void copyMembers(DateFormatSymbols src, DateFormatSymbols dst)
 768     {
 769         dst.eras = Arrays.copyOf(src.eras, src.eras.length);
 770         dst.months = Arrays.copyOf(src.months, src.months.length);
 771         dst.shortMonths = Arrays.copyOf(src.shortMonths, src.shortMonths.length);
 772         dst.weekdays = Arrays.copyOf(src.weekdays, src.weekdays.length);
 773         dst.shortWeekdays = Arrays.copyOf(src.shortWeekdays, src.shortWeekdays.length);
 774         dst.ampms = Arrays.copyOf(src.ampms, src.ampms.length);
 775         if (src.zoneStrings != null) {
 776             dst.zoneStrings = src.getZoneStringsImpl(true);
 777         } else {
 778             dst.zoneStrings = null;
 779         }
 780         dst.localPatternChars = src.localPatternChars;
 781     }
 782 
 783     /**
 784      * Write out the default serializable data, after ensuring the
 785      * <code>zoneStrings</code> field is initialized in order to make
 786      * sure the backward compatibility.
 787      *
 788      * @since 1.6
 789      */
 790     private void writeObject(ObjectOutputStream stream) throws IOException {
 791         if (zoneStrings == null) {
 792             zoneStrings = TimeZoneNameUtility.getZoneStrings(locale);
 793         }
 794         stream.defaultWriteObject();
 795     }
 796 }