Java example source code file (DateFormatSymbols.java)

This example Java source code file (DateFormatSymbols.java) is included in the alvinalexander.com "Java Source Code Warehouse" project. The intent of this project is to help you "Learn Java by Example" ^TM.

Learn more about this Java project at its project page.

Java - Java tags/keywords

dateformatsymbols, dayabbreviations, daynames, eras, localeprovideradapter, pattern_day_of_month, pattern_day_of_week_in_month, pattern_minute, pattern_second, pattern_week_year, runtimeexception, softreference, string, threading, threads, util

The DateFormatSymbols.java Java example source code

/*
 * Copyright (c) 1996, 2013, Oracle and/or its affiliates. All rights reserved.
 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
 *
 * This code is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License version 2 only, as
 * published by the Free Software Foundation.  Oracle designates this
 * particular file as subject to the "Classpath" exception as provided
 * by Oracle in the LICENSE file that accompanied this code.
 *
 * This code is distributed in the hope that it will be useful, but WITHOUT
 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
 * version 2 for more details (a copy is included in the LICENSE file that
 * accompanied this code).
 *
 * You should have received a copy of the GNU General Public License version
 * 2 along with this work; if not, write to the Free Software Foundation,
 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
 *
 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
 * or visit www.oracle.com if you need additional information or have any
 * questions.
 */

/*
 * (C) Copyright Taligent, Inc. 1996 - All Rights Reserved
 * (C) Copyright IBM Corp. 1996 - All Rights Reserved
 *
 *   The original version of this source code and documentation is copyrighted
 * and owned by Taligent, Inc., a wholly-owned subsidiary of IBM. These
 * materials are provided under terms of a License Agreement between Taligent
 * and Sun. This technology is protected by multiple US and International
 * patents. This notice and attribution to Taligent may not be removed.
 *   Taligent is a registered trademark of Taligent, Inc.
 *
 */

package java.text;

import java.io.IOException;
import java.io.ObjectOutputStream;
import java.io.Serializable;
import java.lang.ref.SoftReference;
import java.text.spi.DateFormatSymbolsProvider;
import java.util.Arrays;
import java.util.Locale;
import java.util.Objects;
import java.util.ResourceBundle;
import java.util.TimeZone;
import java.util.concurrent.ConcurrentHashMap;
import java.util.concurrent.ConcurrentMap;
import sun.util.locale.provider.LocaleProviderAdapter;
import sun.util.locale.provider.LocaleServiceProviderPool;
import sun.util.locale.provider.ResourceBundleBasedAdapter;
import sun.util.locale.provider.TimeZoneNameUtility;

/**
 * <code>DateFormatSymbols is a public class for encapsulating
 * localizable date-time formatting data, such as the names of the
 * months, the names of the days of the week, and the time zone data.
 * <code>SimpleDateFormat uses
 * <code>DateFormatSymbols to encapsulate this information.
 *
 * <p>
 * Typically you shouldn't use <code>DateFormatSymbols directly.
 * Rather, you are encouraged to create a date-time formatter with the
 * <code>DateFormat class's factory methods: getTimeInstance,
 * <code>getDateInstance, or getDateTimeInstance.
 * These methods automatically create a <code>DateFormatSymbols for
 * the formatter so that you don't have to. After the
 * formatter is created, you may modify its format pattern using the
 * <code>setPattern method. For more information about
 * creating formatters using <code>DateFormat's factory methods,
 * see {@link DateFormat}.
 *
 * <p>
 * If you decide to create a date-time formatter with a specific
 * format pattern for a specific locale, you can do so with:
 * <blockquote>
 * <pre>
 * new SimpleDateFormat(aPattern, DateFormatSymbols.getInstance(aLocale)).
 * </pre>
 * </blockquote>
 *
 * <p>
 * <code>DateFormatSymbols objects are cloneable. When you obtain
 * a <code>DateFormatSymbols object, feel free to modify the
 * date-time formatting data. For instance, you can replace the localized
 * date-time format pattern characters with the ones that you feel easy
 * to remember. Or you can change the representative cities
 * to your favorite ones.
 *
 * <p>
 * New <code>DateFormatSymbols subclasses may be added to support
 * <code>SimpleDateFormat for date-time formatting for additional locales.

 * @see          DateFormat
 * @see          SimpleDateFormat
 * @see          java.util.SimpleTimeZone
 * @author       Chen-Lieh Huang
 */
public class DateFormatSymbols implements Serializable, Cloneable {

    /**
     * Construct a DateFormatSymbols object by loading format data from
     * resources for the default {@link java.util.Locale.Category#FORMAT FORMAT}
     * locale. This constructor can only
     * construct instances for the locales supported by the Java
     * runtime environment, not for those supported by installed
     * {@link java.text.spi.DateFormatSymbolsProvider DateFormatSymbolsProvider}
     * implementations. For full locale coverage, use the
     * {@link #getInstance(Locale) getInstance} method.
     * <p>This is equivalent to calling
     * {@link #DateFormatSymbols(Locale)
     *     DateFormatSymbols(Locale.getDefault(Locale.Category.FORMAT))}.
     * @see #getInstance()
     * @see java.util.Locale#getDefault(java.util.Locale.Category)
     * @see java.util.Locale.Category#FORMAT
     * @exception  java.util.MissingResourceException
     *             if the resources for the default locale cannot be
     *             found or cannot be loaded.
     */
    public DateFormatSymbols()
    {
        initializeData(Locale.getDefault(Locale.Category.FORMAT));
    }

    /**
     * Construct a DateFormatSymbols object by loading format data from
     * resources for the given locale. This constructor can only
     * construct instances for the locales supported by the Java
     * runtime environment, not for those supported by installed
     * {@link java.text.spi.DateFormatSymbolsProvider DateFormatSymbolsProvider}
     * implementations. For full locale coverage, use the
     * {@link #getInstance(Locale) getInstance} method.
     *
     * @param locale the desired locale
     * @see #getInstance(Locale)
     * @exception  java.util.MissingResourceException
     *             if the resources for the specified locale cannot be
     *             found or cannot be loaded.
     */
    public DateFormatSymbols(Locale locale)
    {
        initializeData(locale);
    }

    /**
     * Era strings. For example: "AD" and "BC".  An array of 2 strings,
     * indexed by <code>Calendar.BC and Calendar.AD.
     * @serial
     */
    String eras[] = null;

    /**
     * Month strings. For example: "January", "February", etc.  An array
     * of 13 strings (some calendars have 13 months), indexed by
     * <code>Calendar.JANUARY, Calendar.FEBRUARY, etc.
     * @serial
     */
    String months[] = null;

    /**
     * Short month strings. For example: "Jan", "Feb", etc.  An array of
     * 13 strings (some calendars have 13 months), indexed by
     * <code>Calendar.JANUARY, Calendar.FEBRUARY, etc.

     * @serial
     */
    String shortMonths[] = null;

    /**
     * Weekday strings. For example: "Sunday", "Monday", etc.  An array
     * of 8 strings, indexed by <code>Calendar.SUNDAY,
     * <code>Calendar.MONDAY, etc.
     * The element <code>weekdays[0] is ignored.
     * @serial
     */
    String weekdays[] = null;

    /**
     * Short weekday strings. For example: "Sun", "Mon", etc.  An array
     * of 8 strings, indexed by <code>Calendar.SUNDAY,
     * <code>Calendar.MONDAY, etc.
     * The element <code>shortWeekdays[0] is ignored.
     * @serial
     */
    String shortWeekdays[] = null;

    /**
     * AM and PM strings. For example: "AM" and "PM".  An array of
     * 2 strings, indexed by <code>Calendar.AM and
     * <code>Calendar.PM.
     * @serial
     */
    String ampms[] = null;

    /**
     * Localized names of time zones in this locale.  This is a
     * two-dimensional array of strings of size <em>n by m,
     * where <em>m is at least 5.  Each of the n rows is an
     * entry containing the localized names for a single <code>TimeZone.
     * Each such row contains (with <code>i ranging from
     * 0..<em>n-1):
     * <ul>
     * <li>zoneStrings[i][0] - time zone ID
     * <li>zoneStrings[i][1] - long name of zone in standard
     * time</li>
     * <li>zoneStrings[i][2] - short name of zone in
     * standard time</li>
     * <li>zoneStrings[i][3] - long name of zone in daylight
     * saving time</li>
     * <li>zoneStrings[i][4] - short name of zone in daylight
     * saving time</li>
     * </ul>
     * The zone ID is <em>not localized; it's one of the valid IDs of
     * the {@link java.util.TimeZone TimeZone} class that are not
     * <a href="../java/util/TimeZone.html#CustomID">custom IDs.
     * All other entries are localized names.
     * @see java.util.TimeZone
     * @serial
     */
    String zoneStrings[][] = null;

    /**
     * Indicates that zoneStrings is set externally with setZoneStrings() method.
     */
    transient boolean isZoneStringsSet = false;

    /**
     * Unlocalized date-time pattern characters. For example: 'y', 'd', etc.
     * All locales use the same these unlocalized pattern characters.
     */
    static final String  patternChars = "GyMdkHmsSEDFwWahKzZYuXL";

    static final int PATTERN_ERA                  =  0; // G
    static final int PATTERN_YEAR                 =  1; // y
    static final int PATTERN_MONTH                =  2; // M
    static final int PATTERN_DAY_OF_MONTH         =  3; // d
    static final int PATTERN_HOUR_OF_DAY1         =  4; // k
    static final int PATTERN_HOUR_OF_DAY0         =  5; // H
    static final int PATTERN_MINUTE               =  6; // m
    static final int PATTERN_SECOND               =  7; // s
    static final int PATTERN_MILLISECOND          =  8; // S
    static final int PATTERN_DAY_OF_WEEK          =  9; // E
    static final int PATTERN_DAY_OF_YEAR          = 10; // D
    static final int PATTERN_DAY_OF_WEEK_IN_MONTH = 11; // F
    static final int PATTERN_WEEK_OF_YEAR         = 12; // w
    static final int PATTERN_WEEK_OF_MONTH        = 13; // W
    static final int PATTERN_AM_PM                = 14; // a
    static final int PATTERN_HOUR1                = 15; // h
    static final int PATTERN_HOUR0                = 16; // K
    static final int PATTERN_ZONE_NAME            = 17; // z
    static final int PATTERN_ZONE_VALUE           = 18; // Z
    static final int PATTERN_WEEK_YEAR            = 19; // Y
    static final int PATTERN_ISO_DAY_OF_WEEK      = 20; // u
    static final int PATTERN_ISO_ZONE             = 21; // X
    static final int PATTERN_MONTH_STANDALONE     = 22; // L

    /**
     * Localized date-time pattern characters. For example, a locale may
     * wish to use 'u' rather than 'y' to represent years in its date format
     * pattern strings.
     * This string must be exactly 18 characters long, with the index of
     * the characters described by <code>DateFormat.ERA_FIELD,
     * <code>DateFormat.YEAR_FIELD, etc.  Thus, if the string were
     * "Xz...", then localized patterns would use 'X' for era and 'z' for year.
     * @serial
     */
    String  localPatternChars = null;

    /**
     * The locale which is used for initializing this DateFormatSymbols object.
     *
     * @since 1.6
     * @serial
     */
    Locale locale = null;

    /* use serialVersionUID from JDK 1.1.4 for interoperability */
    static final long serialVersionUID = -5987973545549424702L;

    /**
     * Returns an array of all locales for which the
     * <code>getInstance methods of this class can return
     * localized instances.
     * The returned array represents the union of locales supported by the
     * Java runtime and by installed
     * {@link java.text.spi.DateFormatSymbolsProvider DateFormatSymbolsProvider}
     * implementations.  It must contain at least a <code>Locale
     * instance equal to {@link java.util.Locale#US Locale.US}.
     *
     * @return An array of locales for which localized
     *         <code>DateFormatSymbols instances are available.
     * @since 1.6
     */
    public static Locale[] getAvailableLocales() {
        LocaleServiceProviderPool pool=
            LocaleServiceProviderPool.getPool(DateFormatSymbolsProvider.class);
        return pool.getAvailableLocales();
    }

    /**
     * Gets the <code>DateFormatSymbols instance for the default
     * locale.  This method provides access to <code>DateFormatSymbols
     * instances for locales supported by the Java runtime itself as well
     * as for those supported by installed
     * {@link java.text.spi.DateFormatSymbolsProvider DateFormatSymbolsProvider}
     * implementations.
     * <p>This is equivalent to calling {@link #getInstance(Locale)
     *     getInstance(Locale.getDefault(Locale.Category.FORMAT))}.
     * @see java.util.Locale#getDefault(java.util.Locale.Category)
     * @see java.util.Locale.Category#FORMAT
     * @return a <code>DateFormatSymbols instance.
     * @since 1.6
     */
    public static final DateFormatSymbols getInstance() {
        return getInstance(Locale.getDefault(Locale.Category.FORMAT));
    }

    /**
     * Gets the <code>DateFormatSymbols instance for the specified
     * locale.  This method provides access to <code>DateFormatSymbols
     * instances for locales supported by the Java runtime itself as well
     * as for those supported by installed
     * {@link java.text.spi.DateFormatSymbolsProvider DateFormatSymbolsProvider}
     * implementations.
     * @param locale the given locale.
     * @return a <code>DateFormatSymbols instance.
     * @exception NullPointerException if <code>locale is null
     * @since 1.6
     */
    public static final DateFormatSymbols getInstance(Locale locale) {
        DateFormatSymbols dfs = getProviderInstance(locale);
        if (dfs != null) {
            return dfs;
        }
        throw new RuntimeException("DateFormatSymbols instance creation failed.");
    }

    /**
     * Returns a DateFormatSymbols provided by a provider or found in
     * the cache. Note that this method returns a cached instance,
     * not its clone. Therefore, the instance should never be given to
     * an application.
     */
    static final DateFormatSymbols getInstanceRef(Locale locale) {
        DateFormatSymbols dfs = getProviderInstance(locale);
        if (dfs != null) {
            return dfs;
        }
        throw new RuntimeException("DateFormatSymbols instance creation failed.");
    }

    private static DateFormatSymbols getProviderInstance(Locale locale) {
        LocaleProviderAdapter adapter = LocaleProviderAdapter.getAdapter(DateFormatSymbolsProvider.class, locale);
        DateFormatSymbolsProvider provider = adapter.getDateFormatSymbolsProvider();
        DateFormatSymbols dfsyms = provider.getInstance(locale);
        if (dfsyms == null) {
            provider = LocaleProviderAdapter.forJRE().getDateFormatSymbolsProvider();
            dfsyms = provider.getInstance(locale);
        }
        return dfsyms;
    }

    /**
     * Gets era strings. For example: "AD" and "BC".
     * @return the era strings.
     */
    public String[] getEras() {
        return Arrays.copyOf(eras, eras.length);
    }

    /**
     * Sets era strings. For example: "AD" and "BC".
     * @param newEras the new era strings.
     */
    public void setEras(String[] newEras) {
        eras = Arrays.copyOf(newEras, newEras.length);
        cachedHashCode = 0;
    }

    /**
     * Gets month strings. For example: "January", "February", etc.
     *
     * <p>If the language requires different forms for formatting and
     * stand-alone usages, this method returns month names in the
     * formatting form. For example, the preferred month name for
     * January in the Czech language is <em>ledna in the
     * formatting form, while it is <em>leden in the stand-alone
     * form. This method returns {@code "ledna"} in this case. Refer
     * to the <a href="http://unicode.org/reports/tr35/#Calendar_Elements">
     * Calendar Elements in the Unicode Locale Data Markup Language
     * (LDML) specification</a> for more details.
     *
     * @return the month strings.
     */
    public String[] getMonths() {
        return Arrays.copyOf(months, months.length);
    }

    /**
     * Sets month strings. For example: "January", "February", etc.
     * @param newMonths the new month strings.
     */
    public void setMonths(String[] newMonths) {
        months = Arrays.copyOf(newMonths, newMonths.length);
        cachedHashCode = 0;
    }

    /**
     * Gets short month strings. For example: "Jan", "Feb", etc.
     *
     * <p>If the language requires different forms for formatting and
     * stand-alone usages, This method returns short month names in
     * the formatting form. For example, the preferred abbreviation
     * for January in the Catalan language is <em>de gen. in the
     * formatting form, while it is <em>gen. in the stand-alone
     * form. This method returns {@code "de gen."} in this case. Refer
     * to the <a href="http://unicode.org/reports/tr35/#Calendar_Elements">
     * Calendar Elements in the Unicode Locale Data Markup Language
     * (LDML) specification</a> for more details.
     *
     * @return the short month strings.
     */
    public String[] getShortMonths() {
        return Arrays.copyOf(shortMonths, shortMonths.length);
    }

    /**
     * Sets short month strings. For example: "Jan", "Feb", etc.
     * @param newShortMonths the new short month strings.
     */
    public void setShortMonths(String[] newShortMonths) {
        shortMonths = Arrays.copyOf(newShortMonths, newShortMonths.length);
        cachedHashCode = 0;
    }

    /**
     * Gets weekday strings. For example: "Sunday", "Monday", etc.
     * @return the weekday strings. Use <code>Calendar.SUNDAY,
     * <code>Calendar.MONDAY, etc. to index the result array.
     */
    public String[] getWeekdays() {
        return Arrays.copyOf(weekdays, weekdays.length);
    }

    /**
     * Sets weekday strings. For example: "Sunday", "Monday", etc.
     * @param newWeekdays the new weekday strings. The array should
     * be indexed by <code>Calendar.SUNDAY,
     * <code>Calendar.MONDAY, etc.
     */
    public void setWeekdays(String[] newWeekdays) {
        weekdays = Arrays.copyOf(newWeekdays, newWeekdays.length);
        cachedHashCode = 0;
    }

    /**
     * Gets short weekday strings. For example: "Sun", "Mon", etc.
     * @return the short weekday strings. Use <code>Calendar.SUNDAY,
     * <code>Calendar.MONDAY, etc. to index the result array.
     */
    public String[] getShortWeekdays() {
        return Arrays.copyOf(shortWeekdays, shortWeekdays.length);
    }

    /**
     * Sets short weekday strings. For example: "Sun", "Mon", etc.
     * @param newShortWeekdays the new short weekday strings. The array should
     * be indexed by <code>Calendar.SUNDAY,
     * <code>Calendar.MONDAY, etc.
     */
    public void setShortWeekdays(String[] newShortWeekdays) {
        shortWeekdays = Arrays.copyOf(newShortWeekdays, newShortWeekdays.length);
        cachedHashCode = 0;
    }

    /**
     * Gets ampm strings. For example: "AM" and "PM".
     * @return the ampm strings.
     */
    public String[] getAmPmStrings() {
        return Arrays.copyOf(ampms, ampms.length);
    }

    /**
     * Sets ampm strings. For example: "AM" and "PM".
     * @param newAmpms the new ampm strings.
     */
    public void setAmPmStrings(String[] newAmpms) {
        ampms = Arrays.copyOf(newAmpms, newAmpms.length);
        cachedHashCode = 0;
    }

    /**
     * Gets time zone strings.  Use of this method is discouraged; use
     * {@link java.util.TimeZone#getDisplayName() TimeZone.getDisplayName()}
     * instead.
     * <p>
     * The value returned is a
     * two-dimensional array of strings of size <em>n by m,
     * where <em>m is at least 5.  Each of the n rows is an
     * entry containing the localized names for a single <code>TimeZone.
     * Each such row contains (with <code>i ranging from
     * 0..<em>n-1):
     * <ul>
     * <li>zoneStrings[i][0] - time zone ID
     * <li>zoneStrings[i][1] - long name of zone in standard
     * time</li>
     * <li>zoneStrings[i][2] - short name of zone in
     * standard time</li>
     * <li>zoneStrings[i][3] - long name of zone in daylight
     * saving time</li>
     * <li>zoneStrings[i][4] - short name of zone in daylight
     * saving time</li>
     * </ul>
     * The zone ID is <em>not localized; it's one of the valid IDs of
     * the {@link java.util.TimeZone TimeZone} class that are not
     * <a href="../util/TimeZone.html#CustomID">custom IDs.
     * All other entries are localized names.  If a zone does not implement
     * daylight saving time, the daylight saving time names should not be used.
     * <p>
     * If {@link #setZoneStrings(String[][]) setZoneStrings} has been called
     * on this <code>DateFormatSymbols instance, then the strings
     * provided by that call are returned. Otherwise, the returned array
     * contains names provided by the Java runtime and by installed
     * {@link java.util.spi.TimeZoneNameProvider TimeZoneNameProvider}
     * implementations.
     *
     * @return the time zone strings.
     * @see #setZoneStrings(String[][])
     */
    public String[][] getZoneStrings() {
        return getZoneStringsImpl(true);
    }

    /**
     * Sets time zone strings.  The argument must be a
     * two-dimensional array of strings of size <em>n by m,
     * where <em>m is at least 5.  Each of the n rows is an
     * entry containing the localized names for a single <code>TimeZone.
     * Each such row contains (with <code>i ranging from
     * 0..<em>n-1):
     * <ul>
     * <li>zoneStrings[i][0] - time zone ID
     * <li>zoneStrings[i][1] - long name of zone in standard
     * time</li>
     * <li>zoneStrings[i][2] - short name of zone in
     * standard time</li>
     * <li>zoneStrings[i][3] - long name of zone in daylight
     * saving time</li>
     * <li>zoneStrings[i][4] - short name of zone in daylight
     * saving time</li>
     * </ul>
     * The zone ID is <em>not localized; it's one of the valid IDs of
     * the {@link java.util.TimeZone TimeZone} class that are not
     * <a href="../util/TimeZone.html#CustomID">custom IDs.
     * All other entries are localized names.
     *
     * @param newZoneStrings the new time zone strings.
     * @exception IllegalArgumentException if the length of any row in
     *    <code>newZoneStrings is less than 5
     * @exception NullPointerException if <code>newZoneStrings is null
     * @see #getZoneStrings()
     */
    public void setZoneStrings(String[][] newZoneStrings) {
        String[][] aCopy = new String[newZoneStrings.length][];
        for (int i = 0; i < newZoneStrings.length; ++i) {
            int len = newZoneStrings[i].length;
            if (len < 5) {
                throw new IllegalArgumentException();
            }
            aCopy[i] = Arrays.copyOf(newZoneStrings[i], len);
        }
        zoneStrings = aCopy;
        isZoneStringsSet = true;
        cachedHashCode = 0;
    }

    /**
     * Gets localized date-time pattern characters. For example: 'u', 't', etc.
     * @return the localized date-time pattern characters.
     */
    public String getLocalPatternChars() {
        return localPatternChars;
    }

    /**
     * Sets localized date-time pattern characters. For example: 'u', 't', etc.
     * @param newLocalPatternChars the new localized date-time
     * pattern characters.
     */
    public void setLocalPatternChars(String newLocalPatternChars) {
        // Call toString() to throw an NPE in case the argument is null
        localPatternChars = newLocalPatternChars.toString();
        cachedHashCode = 0;
    }

    /**
     * Overrides Cloneable
     */
    public Object clone()
    {
        try
        {
            DateFormatSymbols other = (DateFormatSymbols)super.clone();
            copyMembers(this, other);
            return other;
        } catch (CloneNotSupportedException e) {
            throw new InternalError(e);
        }
    }

    /**
     * Override hashCode.
     * Generates a hash code for the DateFormatSymbols object.
     */
    @Override
    public int hashCode() {
        int hashCode = cachedHashCode;
        if (hashCode == 0) {
            hashCode = 5;
            hashCode = 11 * hashCode + Arrays.hashCode(eras);
            hashCode = 11 * hashCode + Arrays.hashCode(months);
            hashCode = 11 * hashCode + Arrays.hashCode(shortMonths);
            hashCode = 11 * hashCode + Arrays.hashCode(weekdays);
            hashCode = 11 * hashCode + Arrays.hashCode(shortWeekdays);
            hashCode = 11 * hashCode + Arrays.hashCode(ampms);
            hashCode = 11 * hashCode + Arrays.deepHashCode(getZoneStringsWrapper());
            hashCode = 11 * hashCode + Objects.hashCode(localPatternChars);
            cachedHashCode = hashCode;
        }

        return hashCode;
    }

    /**
     * Override equals
     */
    public boolean equals(Object obj)
    {
        if (this == obj) return true;
        if (obj == null || getClass() != obj.getClass()) return false;
        DateFormatSymbols that = (DateFormatSymbols) obj;
        return (Arrays.equals(eras, that.eras)
                && Arrays.equals(months, that.months)
                && Arrays.equals(shortMonths, that.shortMonths)
                && Arrays.equals(weekdays, that.weekdays)
                && Arrays.equals(shortWeekdays, that.shortWeekdays)
                && Arrays.equals(ampms, that.ampms)
                && Arrays.deepEquals(getZoneStringsWrapper(), that.getZoneStringsWrapper())
                && ((localPatternChars != null
                  && localPatternChars.equals(that.localPatternChars))
                 || (localPatternChars == null
                  && that.localPatternChars == null)));
    }

    // =======================privates===============================

    /**
     * Useful constant for defining time zone offsets.
     */
    static final int millisPerHour = 60*60*1000;

    /**
     * Cache to hold DateFormatSymbols instances per Locale.
     */
    private static final ConcurrentMap<Locale, SoftReference cachedInstances
        = new ConcurrentHashMap<>(3);

    private transient int lastZoneIndex = 0;

    /**
     * Cached hash code
     */
    transient volatile int cachedHashCode = 0;

    private void initializeData(Locale desiredLocale) {
        locale = desiredLocale;

        // Copy values of a cached instance if any.
        SoftReference<DateFormatSymbols> ref = cachedInstances.get(locale);
        DateFormatSymbols dfs;
        if (ref != null && (dfs = ref.get()) != null) {
            copyMembers(dfs, this);
            return;
        }

        // Initialize the fields from the ResourceBundle for locale.
        LocaleProviderAdapter adapter = LocaleProviderAdapter.getAdapter(DateFormatSymbolsProvider.class, locale);
        // Avoid any potential recursions
        if (!(adapter instanceof ResourceBundleBasedAdapter)) {
            adapter = LocaleProviderAdapter.getResourceBundleBased();
        }
        ResourceBundle resource = ((ResourceBundleBasedAdapter)adapter).getLocaleData().getDateFormatData(locale);

        // JRE and CLDR use different keys
        // JRE: Eras, short.Eras and narrow.Eras
        // CLDR: long.Eras, Eras and narrow.Eras
        if (resource.containsKey("Eras")) {
            eras = resource.getStringArray("Eras");
        } else if (resource.containsKey("long.Eras")) {
            eras = resource.getStringArray("long.Eras");
        } else if (resource.containsKey("short.Eras")) {
            eras = resource.getStringArray("short.Eras");
        }
        months = resource.getStringArray("MonthNames");
        shortMonths = resource.getStringArray("MonthAbbreviations");
        ampms = resource.getStringArray("AmPmMarkers");
        localPatternChars = resource.getString("DateTimePatternChars");

        // Day of week names are stored in a 1-based array.
        weekdays = toOneBasedArray(resource.getStringArray("DayNames"));
        shortWeekdays = toOneBasedArray(resource.getStringArray("DayAbbreviations"));

        // Put a clone in the cache
        ref = new SoftReference<>((DateFormatSymbols)this.clone());
        SoftReference<DateFormatSymbols> x = cachedInstances.putIfAbsent(locale, ref);
        if (x != null) {
            DateFormatSymbols y = x.get();
            if (y == null) {
                // Replace the empty SoftReference with ref.
                cachedInstances.put(locale, ref);
            }
        }
    }

    private static String[] toOneBasedArray(String[] src) {
        int len = src.length;
        String[] dst = new String[len + 1];
        dst[0] = "";
        for (int i = 0; i < len; i++) {
            dst[i + 1] = src[i];
        }
        return dst;
    }

    /**
     * Package private: used by SimpleDateFormat
     * Gets the index for the given time zone ID to obtain the time zone
     * strings for formatting. The time zone ID is just for programmatic
     * lookup. NOT LOCALIZED!!!
     * @param ID the given time zone ID.
     * @return the index of the given time zone ID.  Returns -1 if
     * the given time zone ID can't be located in the DateFormatSymbols object.
     * @see java.util.SimpleTimeZone
     */
    final int getZoneIndex(String ID) {
        String[][] zoneStrings = getZoneStringsWrapper();

        /*
         * getZoneIndex has been re-written for performance reasons. instead of
         * traversing the zoneStrings array every time, we cache the last used zone
         * index
         */
        if (lastZoneIndex < zoneStrings.length && ID.equals(zoneStrings[lastZoneIndex][0])) {
            return lastZoneIndex;
        }

        /* slow path, search entire list */
        for (int index = 0; index < zoneStrings.length; index++) {
            if (ID.equals(zoneStrings[index][0])) {
                lastZoneIndex = index;
                return index;
            }
        }

        return -1;
    }

    /**
     * Wrapper method to the getZoneStrings(), which is called from inside
     * the java.text package and not to mutate the returned arrays, so that
     * it does not need to create a defensive copy.
     */
    final String[][] getZoneStringsWrapper() {
        if (isSubclassObject()) {
            return getZoneStrings();
        } else {
            return getZoneStringsImpl(false);
        }
    }

    private String[][] getZoneStringsImpl(boolean needsCopy) {
        if (zoneStrings == null) {
            zoneStrings = TimeZoneNameUtility.getZoneStrings(locale);
        }

        if (!needsCopy) {
            return zoneStrings;
        }

        int len = zoneStrings.length;
        String[][] aCopy = new String[len][];
        for (int i = 0; i < len; i++) {
            aCopy[i] = Arrays.copyOf(zoneStrings[i], zoneStrings[i].length);
        }
        return aCopy;
    }

    private boolean isSubclassObject() {
        return !getClass().getName().equals("java.text.DateFormatSymbols");
    }

    /**
     * Clones all the data members from the source DateFormatSymbols to
     * the target DateFormatSymbols. This is only for subclasses.
     * @param src the source DateFormatSymbols.
     * @param dst the target DateFormatSymbols.
     */
    private void copyMembers(DateFormatSymbols src, DateFormatSymbols dst)
    {
        dst.eras = Arrays.copyOf(src.eras, src.eras.length);
        dst.months = Arrays.copyOf(src.months, src.months.length);
        dst.shortMonths = Arrays.copyOf(src.shortMonths, src.shortMonths.length);
        dst.weekdays = Arrays.copyOf(src.weekdays, src.weekdays.length);
        dst.shortWeekdays = Arrays.copyOf(src.shortWeekdays, src.shortWeekdays.length);
        dst.ampms = Arrays.copyOf(src.ampms, src.ampms.length);
        if (src.zoneStrings != null) {
            dst.zoneStrings = src.getZoneStringsImpl(true);
        } else {
            dst.zoneStrings = null;
        }
        dst.localPatternChars = src.localPatternChars;
        dst.cachedHashCode = 0;
    }

    /**
     * Write out the default serializable data, after ensuring the
     * <code>zoneStrings field is initialized in order to make
     * sure the backward compatibility.
     *
     * @since 1.6
     */
    private void writeObject(ObjectOutputStream stream) throws IOException {
        if (zoneStrings == null) {
            zoneStrings = TimeZoneNameUtility.getZoneStrings(locale);
        }
        stream.defaultWriteObject();
    }
}