/*
 *******************************************************************************
 * Copyright (C) 1996-2010, International Business Machines Corporation and    *
 * others. All Rights Reserved.                                                *
 *******************************************************************************
 */

package com.ibm.icu.text;

import java.io.IOException;
import java.io.ObjectInputStream;
import java.io.Serializable;
import java.util.Locale;
import java.util.MissingResourceException;
import java.util.ResourceBundle;

import com.ibm.icu.impl.CalendarData;
import com.ibm.icu.impl.CalendarUtil;
import com.ibm.icu.impl.ICUCache;
import com.ibm.icu.impl.ICUResourceBundle;
import com.ibm.icu.impl.SimpleCache;
import com.ibm.icu.impl.Utility;
import com.ibm.icu.impl.ZoneMeta;
import com.ibm.icu.impl.ZoneStringFormat;
import com.ibm.icu.util.Calendar;
import com.ibm.icu.util.ULocale;
import com.ibm.icu.util.UResourceBundle;

/**
 * {@icuenhanced java.text.DateFormatSymbols}.{@icu _usage_}
 *
 * <p><code>DateFormatSymbols</code> 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>DateFormat</code> and <code>SimpleDateFormat</code> both use
 * <code>DateFormatSymbols</code> to encapsulate this information.
 *
 * <p>Typically you shouldn't use <code>DateFormatSymbols</code> directly.
 * Rather, you are encouraged to create a date-time formatter with the
 * <code>DateFormat</code> class's factory methods: <code>getTimeInstance</code>,
 * <code>getDateInstance</code>, or <code>getDateTimeInstance</code>.
 * These methods automatically create a <code>DateFormatSymbols</code> 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</code> method. For more information about
 * creating formatters using <code>DateFormat</code>'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, new DateFormatSymbols(aLocale)).
 * </pre>
 * </blockquote>
 *
 * <p><code>DateFormatSymbols</code> objects are clonable. When you obtain
 * a <code>DateFormatSymbols</code> 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</code> subclasses may be added to support
 * <code>SimpleDateFormat</code> for date-time formatting for additional locales.
 *
 * @see          DateFormat
 * @see          SimpleDateFormat
 * @see          com.ibm.icu.util.SimpleTimeZone
 * @author       Chen-Lieh Huang
 * @stable ICU 2.0
 */
public class DateFormatSymbols implements Serializable, Cloneable {

    // TODO make sure local pattern char string is 18 characters long,
    // that is, that it encompasses the new 'u' char for
    // EXTENDED_YEAR.  Two options: 1. Make sure resource data is
    // correct; 2. Make code add in 'u' at end if len == 17.

    // Constants for context
    /**
     * {@icu} Constant for context.
     * @stable ICU 3.6
     */
    public static final int FORMAT = 0;

    /**
     * {@icu} Constant for context.
     * @stable ICU 3.6
     */
    public static final int STANDALONE = 1;

    /**
     * {@icu} Constant for context.
     * @internal
     * @deprecated This API is ICU internal only.
     */
    public static final int DT_CONTEXT_COUNT = 2;

    // Constants for width

    /**
     * {@icu} Constant for width.
     * @stable ICU 3.6
     */
    public static final int ABBREVIATED = 0;

    /**
     * {@icu} Constant for width.
     * @stable ICU 3.6
     */
    public static final int WIDE = 1;

    /**
     * {@icu} Constant for width.
     * @stable ICU 3.6
     */
    public static final int NARROW = 2;

    /**
     * {@icu} Constant for width.
     * @internal
     * @deprecated This API is ICU internal only.
     */
    public static final int DT_WIDTH_COUNT = 3;

    /**
     * Constructs a DateFormatSymbols object by loading format data from
     * resources for the default locale.
     *
     * @throws java.util.MissingResourceException if the resources for the default locale
     *          cannot be found or cannot be loaded.
     * @stable ICU 2.0
     */
    public DateFormatSymbols()
    {
        this(ULocale.getDefault());
    }

    /**
     * Constructs a DateFormatSymbols object by loading format data from
     * resources for the given locale.
     *
     * @throws java.util.MissingResourceException if the resources for the specified
     *          locale cannot be found or cannot be loaded.
     * @stable ICU 2.0
     */
    public DateFormatSymbols(Locale locale)
    {
        this(ULocale.forLocale(locale));
    }

    /**
     * {@icu} Constructs a DateFormatSymbols object by loading format data from
     * resources for the given ulocale.
     *
     * @throws java.util.MissingResourceException if the resources for the specified
     *          locale cannot be found or cannot be loaded.
     * @stable ICU 3.2
     */
    public DateFormatSymbols(ULocale locale)
    {
        initializeData(locale, CalendarUtil.getCalendarType(locale));
    }

    /**
     * Returns a DateFormatSymbols instance for the default locale.
     *
     * {@icunote} Unlike <code>java.text.DateFormatSymbols#getInstance</code>,
     * this method simply returns <code>new com.ibm.icu.text.DateFormatSymbols()</code>.
     * ICU does not support <code>DateFormatSymbolsProvider</code> introduced in Java 6
     * or its equivalent implementation for now.
     *
     * @return A DateFormatSymbols instance.
     * @stable ICU 3.8
     */
    public static DateFormatSymbols getInstance() {
        return new DateFormatSymbols();
    }

    /**
     * Returns a DateFormatSymbols instance for the given locale.
     *
     * {@icunote} Unlike <code>java.text.DateFormatSymbols#getInstance</code>,
     * this method simply returns <code>new com.ibm.icu.text.DateFormatSymbols(locale)</code>.
     * ICU does not support <code>DateFormatSymbolsProvider</code> introduced in Java 6
     * or its equivalent implementation for now.
     *
     * @param locale the locale.
     * @return A DateFormatSymbols instance.
     * @stable ICU 3.8
     */
    public static DateFormatSymbols getInstance(Locale locale) {
        return new DateFormatSymbols(locale);
    }

    /**
     * {@icu} Returns a DateFormatSymbols instance for the given locale.
     *
     * {@icunote} Unlike <code>java.text.DateFormatSymbols#getInstance</code>,
     * this method simply returns <code>new com.ibm.icu.text.DateFormatSymbols(locale)</code>.
     * ICU does not support <code>DateFormatSymbolsProvider</code> introduced in Java 6
     * or its equivalent implementation for now.
     *
     * @param locale the locale.
     * @return A DateFormatSymbols instance.
     * @stable ICU 3.8
     */
    public static DateFormatSymbols getInstance(ULocale locale) {
        return new DateFormatSymbols(locale);
    }

    /**
     * Returns an array of all locales for which the <code>getInstance</code> methods of
     * this class can return localized instances.
     *
     * {@icunote} Unlike <code>java.text.DateFormatSymbols#getAvailableLocales</code>,
     * this method simply returns the array of <code>Locale</code>s available in this
     * class.  ICU does not support <code>DateFormatSymbolsProvider</code> introduced in
     * Java 6 or its equivalent implementation for now.
     *
     * @return An array of <code>Locale</code>s for which localized
     * <code>DateFormatSymbols</code> instances are available.
     * @stable ICU 3.8
     */
    public static Locale[] getAvailableLocales() {
        return ICUResourceBundle.getAvailableLocales();
    }

    /**
     * {@icu} Returns an array of all locales for which the <code>getInstance</code>
     * methods of this class can return localized instances.
     *
     * {@icunote} Unlike <code>java.text.DateFormatSymbols#getAvailableLocales</code>,
     * this method simply returns the array of <code>ULocale</code>s available in this
     * class.  ICU does not support <code>DateFormatSymbolsProvider</code> introduced in
     * Java 6 or its equivalent implementation for now.
     *
     * @return An array of <code>ULocale</code>s for which localized
     * <code>DateFormatSymbols</code> instances are available.
     * @draft ICU 3.8 (retain)
     * @provisional This API might change or be removed in a future release.
     */
    public static ULocale[] getAvailableULocales() {
        return ICUResourceBundle.getAvailableULocales();
    }

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

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

    /**
     * Narrow era names. For example: "A" and "B". An array of 2 strings,
     * indexed by <code>Calendar.BC</code> and <code>Calendar.AD</code>.
     * @serial
     */
    String narrowEras[] = null;

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

    /**
     * Abbreviated quarter names. For example: "Q1", "Q2", "Q3", "Q4". An array
     * of 4 strings indexed by the month divided by 3.
     * @serial
     */
    String shortQuarters[] = null;

    /**
     * Full quarter names. For example: "1st Quarter", "2nd Quarter", "3rd Quarter",
     * "4th Quarter". An array of 4 strings, indexed by the month divided by 3.
     * @serial
     */
    String quarters[] = null;

    /**
     * Standalone abbreviated quarter names. For example: "Q1", "Q2", "Q3", "Q4". An array
     * of 4 strings indexed by the month divided by 3.
     * @serial
     */
    String standaloneShortQuarters[] = null;

    /**
     * Standalone full quarter names. For example: "1st Quarter", "2nd Quarter", "3rd Quarter",
     * "4th Quarter". An array of 4 strings, indexed by the month divided by 3.
     * @serial
     */
    String standaloneQuarters[] = null;

    /**
     * Pattern string used for localized time zone GMT format.  For example, "GMT{0}"
     * @serial
     */
    String gmtFormat = null;

    /**
     * Pattern strings used for formatting zone offset in a localized time zone GMT string.
     * This is 2x2 String array holding followings
     * [0][0] Negative H + m + s
     * [0][1] Negative H + m
     * [1][0] Positive H + m + s
     * [1][1] Positive H + m
     * @serial
     */
    String gmtHourFormats[][] = null;

    /**
     * Localized names of time zones in this locale.  This is a
     * two-dimensional array of strings of size <em>n</em> by <em>m</em>,
     * where <em>m</em> is at least 5 and up to 7.  Each of the <em>n</em> rows is an
     * entry containing the localized names for a single <code>TimeZone</code>.
     * Each such row contains (with <code>i</code> ranging from
     * 0..<em>n</em>-1):
     * <ul>
     * <li><code>zoneStrings[i][0]</code> - time zone ID</li>
     * <li><code>zoneStrings[i][1]</code> - long name of zone in standard
     * time</li>
     * <li><code>zoneStrings[i][2]</code> - short name of zone in
     * standard time</li>
     * <li><code>zoneStrings[i][3]</code> - long name of zone in daylight
     * savings time</li>
     * <li><code>zoneStrings[i][4]</code> - short name of zone in daylight
     * savings time</li>
     * <li><code>zoneStrings[i][5]</code> - location name of zone</li>
     * <li><code>zoneStrings[i][6]</code> - long generic name of zone</li>
     * <li><code>zoneStrings[i][7]</code> - short generic of zone</li>
     * The zone ID is <em>not</em> localized; it corresponds to the ID
     * value associated with a system time zone object.  All other entries
     * are localized names.  If a zone does not implement daylight savings
     * time, the daylight savings time names are ignored.
     * <em>Note:</em>CLDR 1.5 introduced metazone and its historical mappings.
     * This simple two-dimensional array is no longer sufficient to represent
     * localized names and its historic changes.  Since ICU 3.8.1, localized
     * zone names extracted from ICU locale data is stored in a ZoneStringFormat
     * instance.  But we still need to support the old way of customizing
     * localized zone names, so we keep this field for the purpose.
     * @see com.ibm.icu.util.TimeZone
     * @serial
     */
    private String zoneStrings[][] = null;

     /**
      * Since ICU 3.8.1, we use ZoneStringFormat to access localized
      * zone names.  This field remains null unless setZoneStrings is
      * called.
      */
    private transient ZoneStringFormat zsformat = null;

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

    /**
     * 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>,
     * <code>DateFormat.YEAR_FIELD</code>, etc.  Thus, if the string were
     * "Xz...", then localized patterns would use 'X' for era and 'z' for year.
     * @serial
     */
    String localPatternChars = null;

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

    /**
     * Returns era strings. For example: "AD" and "BC".
     * @return the era strings.
     * @stable ICU 2.0
     */
    public String[] getEras() {
        return duplicate(eras);
    }

    /**
     * Sets era strings. For example: "AD" and "BC".
     * @param newEras the new era strings.
     * @stable ICU 2.0
     */
    public void setEras(String[] newEras) {
        eras = duplicate(newEras);
    }

    /**
     * {@icu} Returns era name strings. For example: "Anno Domini" and "Before Christ".
     * @return the era strings.
     * @stable ICU 3.4
     */
    public String[] getEraNames() {
        return duplicate(eraNames);
    }

    /**
     * {@icu} Sets era name strings. For example: "Anno Domini" and "Before Christ".
     * @param newEraNames the new era strings.
     * @stable ICU 3.8
     */
    public void setEraNames(String[] newEraNames) {
        eraNames = duplicate(newEraNames);
    }

    /**
     * Returns month strings. For example: "January", "February", etc.
     * @return the month strings.
     * @stable ICU 2.0
     */
    public String[] getMonths() {
        return duplicate(months);
    }

    /**
     * Returns month strings. For example: "January", "February", etc.
     * @param context    The month context, FORMAT or STANDALONE.
     * @param width      The width or the returned month string,
     *                   either WIDE, ABBREVIATED, or NARROW.
     * @return the month strings.
     * @stable ICU 3.4
     */
    public String[] getMonths(int context, int width) {
        String [] returnValue = null;
        switch (context) {
           case FORMAT :
              switch(width) {
                 case WIDE :
                    returnValue = months;
                    break;
                 case ABBREVIATED :
                    returnValue = shortMonths;
                    break;
                 case NARROW :
                    returnValue = narrowMonths;
                    break;
              }
              break;
           case STANDALONE :
              switch(width) {
                 case WIDE :
                    returnValue = standaloneMonths;
                    break;
                 case ABBREVIATED :
                    returnValue = standaloneShortMonths;
                    break;
                 case NARROW :
                    returnValue = standaloneNarrowMonths;
                    break;
              }
              break;
        }
        return duplicate(returnValue);
    }

    /**
     * Sets month strings. For example: "January", "February", etc.
     * @param newMonths the new month strings.
     * @stable ICU 2.0
     */
    public void setMonths(String[] newMonths) {
        months = duplicate(newMonths);
    }

    /**
     * Sets month strings. For example: "January", "February", etc.
     * @param newMonths the new month strings.
     * @param context    The formatting context, FORMAT or STANDALONE.
     * @param width      The width of the month string,
     *                   either WIDE, ABBREVIATED, or NARROW.
     * @stable ICU 3.8
     */
    public void setMonths(String[] newMonths, int context, int width) {
        switch (context) {
           case FORMAT :
              switch(width) {
                 case WIDE :
                    months = duplicate(newMonths);
                    break;
                 case ABBREVIATED :
                    shortMonths = duplicate(newMonths);
                    break;
                 case NARROW :
                    narrowMonths = duplicate(newMonths);
                    break;
              }
              break;
           case STANDALONE :
              switch(width) {
                 case WIDE :
                    standaloneMonths = duplicate(newMonths);
                    break;
                 case ABBREVIATED :
                    standaloneShortMonths = duplicate(newMonths);
                    break;
                 case NARROW :
                    standaloneNarrowMonths = duplicate(newMonths);
                    break;
              }
              break;
        }
    }

    /**
     * Returns short month strings. For example: "Jan", "Feb", etc.
     * @return the short month strings.
     * @stable ICU 2.0
     */
    public String[] getShortMonths() {
        return duplicate(shortMonths);
    }

    /**
     * Sets short month strings. For example: "Jan", "Feb", etc.
     * @param newShortMonths the new short month strings.
     * @stable ICU 2.0
     */
    public void setShortMonths(String[] newShortMonths) {
        shortMonths = duplicate(newShortMonths);
    }

    /**
     * Returns weekday strings. For example: "Sunday", "Monday", etc.
     * @return the weekday strings. Use <code>Calendar.SUNDAY</code>,
     * <code>Calendar.MONDAY</code>, etc. to index the result array.
     * @stable ICU 2.0
     */
    public String[] getWeekdays() {
        return duplicate(weekdays);
    }

    /**
     * Returns weekday strings. For example: "Sunday", "Monday", etc.
     * @return the weekday strings. Use <code>Calendar.SUNDAY</code>,
     * <code>Calendar.MONDAY</code>, etc. to index the result array.
     * @param context    Formatting context, either FORMAT or STANDALONE.
     * @param width      Width of strings to be returned, either
     *                   WIDE, ABBREVIATED, or NARROW
     * @stable ICU 3.4
     */
    public String[] getWeekdays(int context, int width) {
        String [] returnValue = null;
        switch (context) {
           case FORMAT :
              switch(width) {
                 case WIDE :
                    returnValue = weekdays;
                    break;
                 case ABBREVIATED :
                    returnValue = shortWeekdays;
                    break;
                 case NARROW :
                    returnValue = narrowWeekdays;
                    break;
              }
              break;
           case STANDALONE :
              switch(width) {
                 case WIDE :
                    returnValue = standaloneWeekdays;
                    break;
                 case ABBREVIATED :
                    returnValue = standaloneShortWeekdays;
                    break;
                 case NARROW :
                    returnValue = standaloneNarrowWeekdays;
                    break;
              }
              break;
        }
        return duplicate(returnValue);
    }

    /**
     * Sets weekday strings. For example: "Sunday", "Monday", etc.
     * @param newWeekdays The new weekday strings.
     * @param context     The formatting context, FORMAT or STANDALONE.
     * @param width       The width of the strings,
     *                    either WIDE, ABBREVIATED, or NARROW.
     * @stable ICU 3.8
     */
    public void setWeekdays(String[] newWeekdays, int context, int width) {
        switch (context) {
           case FORMAT :
              switch(width) {
                 case WIDE :
                    weekdays = duplicate(newWeekdays);
                    break;
                 case ABBREVIATED :
                    shortWeekdays = duplicate(newWeekdays);
                    break;
                 case NARROW :
                    narrowWeekdays = duplicate(newWeekdays);
                    break;
              }
              break;
           case STANDALONE :
              switch(width) {
                 case WIDE :
                    standaloneWeekdays = duplicate(newWeekdays);
                    break;
                 case ABBREVIATED :
                    standaloneShortWeekdays = duplicate(newWeekdays);
                    break;
                 case NARROW :
                    standaloneNarrowWeekdays = duplicate(newWeekdays);
                    break;
              }
              break;
        }
    }

    /**
     * Sets weekday strings. For example: "Sunday", "Monday", etc.
     * @param newWeekdays the new weekday strings. The array should
     * be indexed by <code>Calendar.SUNDAY</code>,
     * <code>Calendar.MONDAY</code>, etc.
     * @stable ICU 2.0
     */
    public void setWeekdays(String[] newWeekdays) {
        weekdays = duplicate(newWeekdays);
    }

    /**
     * Returns short weekday strings. For example: "Sun", "Mon", etc.
     * @return the short weekday strings. Use <code>Calendar.SUNDAY</code>,
     * <code>Calendar.MONDAY</code>, etc. to index the result array.
     * @stable ICU 2.0
     */
    public String[] getShortWeekdays() {
        return duplicate(shortWeekdays);
    }

    /**
     * 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>,
     * <code>Calendar.MONDAY</code>, etc.
     * @stable ICU 2.0
     */
    public void setShortWeekdays(String[] newShortWeekdays) {
        shortWeekdays = duplicate(newShortWeekdays);
    }
    /**
     * {@icu} Returns quarter strings. For example: "1st Quarter", "2nd Quarter", etc.
     * @param context    The quarter context, FORMAT or STANDALONE.
     * @param width      The width or the returned quarter string,
     *                   either WIDE or ABBREVIATED. There are no NARROW quarters.
     * @return the quarter strings.
     * @stable ICU 3.6
     */
    public String[] getQuarters(int context, int width) {
        String [] returnValue = null;
        switch (context) {
           case FORMAT :
              switch(width) {
                 case WIDE :
                    returnValue = quarters;
                    break;
                 case ABBREVIATED :
                    returnValue = shortQuarters;
                    break;
                 case NARROW :
                     returnValue = null;
                     break;
              }
              break;

           case STANDALONE :
              switch(width) {
                 case WIDE :
                    returnValue = standaloneQuarters;
                    break;
                 case ABBREVIATED :
                    returnValue = standaloneShortQuarters;
                    break;
                 case NARROW:
                     returnValue = null;
                     break;
              }
              break;
        }
        return duplicate(returnValue);
    }

    /**
     * {@icu} Sets quarter strings. For example: "1st Quarter", "2nd Quarter", etc.
     * @param newQuarters the new quarter strings.
     * @param context    The formatting context, FORMAT or STANDALONE.
     * @param width      The width of the quarter string,
     *                   either WIDE or ABBREVIATED. There are no NARROW quarters.
     * @stable ICU 3.8
     */
    public void setQuarters(String[] newQuarters, int context, int width) {
        switch (context) {
           case FORMAT :
              switch(width) {
                 case WIDE :
                    quarters = duplicate(newQuarters);
                    break;
                 case ABBREVIATED :
                    shortQuarters = duplicate(newQuarters);
                    break;
                 case NARROW :
                    //narrowQuarters = duplicate(newQuarters);
                    break;
              }
              break;
           case STANDALONE :
              switch(width) {
                 case WIDE :
                    standaloneQuarters = duplicate(newQuarters);
                    break;
                 case ABBREVIATED :
                    standaloneShortQuarters = duplicate(newQuarters);
                    break;
                 case NARROW :
                    //standaloneNarrowQuarters = duplicate(newQuarters);
                    break;
              }
              break;
        }
    }

    /**
     * Returns am/pm strings. For example: "AM" and "PM".
     * @return the weekday strings.
     * @stable ICU 2.0
     */
    public String[] getAmPmStrings() {
        return duplicate(ampms);
    }

    /**
     * Sets am/pm strings. For example: "AM" and "PM".
     * @param newAmpms the new ampm strings.
     * @stable ICU 2.0
     */
    public void setAmPmStrings(String[] newAmpms) {
        ampms = duplicate(newAmpms);
    }

    /**
     * Returns timezone strings.
     * @return the timezone strings.
     * @stable ICU 2.0
     */
    public String[][] getZoneStrings() {
        if (zoneStrings != null) {
            return duplicate(zoneStrings);
        }
        return ZoneStringFormat.getInstance(requestedLocale).getZoneStrings();
    }

    /**
     * Sets timezone strings.
     * @param newZoneStrings the new timezone strings.
     * @stable ICU 2.0
     */
    public void setZoneStrings(String[][] newZoneStrings) {
        zoneStrings = duplicate(newZoneStrings);
        zsformat = new ZoneStringFormat(zoneStrings);
    }

    /**
     * Returns localized date-time pattern characters. For example: 'u', 't', etc.
     *
     * <p>Note: ICU no longer provides localized date-time pattern characters for a locale
     * starting ICU 3.8.  This method returns the non-localized date-time pattern
     * characters unless user defined localized data is set by setLocalPatternChars.
     * @return the localized date-time pattern characters.
     * @stable ICU 2.0
     */
    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.
     * @stable ICU 2.0
     */
    public void setLocalPatternChars(String newLocalPatternChars) {
        localPatternChars = newLocalPatternChars;
    }

    /**
     * Overrides clone.
     * @stable ICU 2.0
     */
    public Object clone()
    {
        try {
            DateFormatSymbols other = (DateFormatSymbols)super.clone();
            return other;
        } catch (CloneNotSupportedException e) {
            ///CLOVER:OFF
            throw new IllegalStateException();
            ///CLOVER:ON
        }
    }

    /**
     * Override hashCode.
     * Generates a hash code for the DateFormatSymbols object.
     * @stable ICU 2.0
     */
    public int hashCode() {
        // Is this sufficient?
        return requestedLocale.toString().hashCode();
    }

    /**
     * Overrides equals.
     * @stable ICU 2.0
     */
    public boolean equals(Object obj)
    {
        if (this == obj) return true;
        if (obj == null || getClass() != obj.getClass()) return false;
        DateFormatSymbols that = (DateFormatSymbols) obj;
        return (Utility.arrayEquals(eras, that.eras)
                && Utility.arrayEquals(eraNames, that.eraNames)
                && Utility.arrayEquals(months, that.months)
                && Utility.arrayEquals(shortMonths, that.shortMonths)
                && Utility.arrayEquals(narrowMonths, that.narrowMonths)
                && Utility.arrayEquals(standaloneMonths, that.standaloneMonths)
                && Utility.arrayEquals(standaloneShortMonths, that.standaloneShortMonths)
                && Utility.arrayEquals(standaloneNarrowMonths, that.standaloneNarrowMonths)
                && Utility.arrayEquals(weekdays, that.weekdays)
                && Utility.arrayEquals(shortWeekdays, that.shortWeekdays)
                && Utility.arrayEquals(narrowWeekdays, that.narrowWeekdays)
                && Utility.arrayEquals(standaloneWeekdays, that.standaloneWeekdays)
                && Utility.arrayEquals(standaloneShortWeekdays, that.standaloneShortWeekdays)
                && Utility.arrayEquals(standaloneNarrowWeekdays, that.standaloneNarrowWeekdays)
                && Utility.arrayEquals(ampms, that.ampms)
                && gmtFormat.equals(that.gmtFormat)
                && arrayOfArrayEquals(gmtHourFormats, that.gmtHourFormats)
                && arrayOfArrayEquals(zoneStrings, that.zoneStrings)
                // getDiplayName maps deprecated country and language codes to the current ones
                // too bad there is no way to get the current codes!
                // I thought canolicalize() would map the codes but .. alas! it doesn't.
                && requestedLocale.getDisplayName().equals(that.requestedLocale.getDisplayName())
                && Utility.arrayEquals(localPatternChars,
                                       that.localPatternChars));
    }

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

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

    // DateFormatSymbols cache
    private static ICUCache<String, DateFormatSymbols> DFSCACHE =
        new SimpleCache<String, DateFormatSymbols>();

    /**
     * Initializes format symbols for the locale and calendar type
     * @param desiredLocale The locale whose symbols are desired.
     * @param type          The calendar type whose date format symbols are desired.
     * @stable ICU 3.0
     */
    //TODO: This protected seems to be marked as @stable accidentally.
    // We may need to deescalate this API to @internal.
    protected void initializeData(ULocale desiredLocale, String type)
    {
        String key = desiredLocale.toString() + "+" + type;
        DateFormatSymbols dfs = DFSCACHE.get(key);
        if (dfs == null) {
            // Initialize data from scratch put a clone of this instance into the cache
            CalendarData calData = new CalendarData(desiredLocale, type);
            initializeData(desiredLocale, calData);
            dfs = (DateFormatSymbols)this.clone();
            DFSCACHE.put(key, dfs);
        } else {
            initializeData(dfs);
        }
    }

    /**
     * Initializes format symbols using another instance.
     *
     * TODO Clean up initialization methods for subclasses
     */
    void initializeData(DateFormatSymbols dfs) {
        this.eras = dfs.eras;
        this.eraNames = dfs.eraNames;
        this.narrowEras = dfs.narrowEras;
        this.months = dfs.months;
        this.shortMonths = dfs.shortMonths;
        this.narrowMonths = dfs.narrowMonths;
        this.standaloneMonths = dfs.standaloneMonths;
        this.standaloneShortMonths = dfs.standaloneShortMonths;
        this.standaloneNarrowMonths = dfs.standaloneNarrowMonths;
        this.weekdays = dfs.weekdays;
        this.shortWeekdays = dfs.shortWeekdays;
        this.narrowWeekdays = dfs.narrowWeekdays;
        this.standaloneWeekdays = dfs.standaloneWeekdays;
        this.standaloneShortWeekdays = dfs.standaloneShortWeekdays;
        this.standaloneNarrowWeekdays = dfs.standaloneNarrowWeekdays;
        this.ampms = dfs.ampms;
        this.shortQuarters = dfs.shortQuarters;
        this.quarters = dfs.quarters;
        this.standaloneShortQuarters = dfs.standaloneShortQuarters;
        this.standaloneQuarters = dfs.standaloneQuarters;

        this.gmtFormat = dfs.gmtFormat;
        this.gmtHourFormats = dfs.gmtHourFormats;

        this.zoneStrings = dfs.zoneStrings; // always null at initialization time for now
        this.localPatternChars = dfs.localPatternChars;

        this.actualLocale = dfs.actualLocale;
        this.validLocale = dfs.validLocale;
        this.requestedLocale = dfs.requestedLocale;
    }

    /**
     * Initializes format symbols for the locale and calendar type
     * @param desiredLocale The locale whose symbols are desired.
     * @param calData       The calendar resource data
     * @internal
     * @deprecated This API is ICU internal only.
     */
    // This API was accidentally marked as @stable ICU 3.0 formerly.
    protected void initializeData(ULocale desiredLocale, CalendarData calData)
    {
        // FIXME: cache only ResourceBundle. Hence every time, will do
        // getObject(). This won't be necessary if the Resource itself
        // is cached.
        eras = calData.getEras("abbreviated");

        try {
           eraNames = calData.getEras("wide");
        }
        catch (MissingResourceException e) {
           eraNames = calData.getEras("abbreviated");
        }

        // NOTE: since the above code assumes that abbreviated
        // era names exist, we make the same assumption here too.
        try {
            narrowEras = calData.getEras("narrow");
        } catch (MissingResourceException e) {
            narrowEras = calData.getEras("abbreviated");
        }

        months = calData.getStringArray("monthNames", "wide");
        shortMonths = calData.getStringArray("monthNames", "abbreviated");

        try {
           narrowMonths = calData.getStringArray("monthNames", "narrow");
        }
        catch (MissingResourceException e) {
            try {
                narrowMonths = calData.getStringArray("monthNames", "stand-alone", "narrow");
            }
            catch (MissingResourceException e1) {
               narrowMonths = calData.getStringArray("monthNames", "abbreviated");
            }
        }

        try {
           standaloneMonths = calData.getStringArray("monthNames", "stand-alone", "wide");
        }
        catch (MissingResourceException e) {
           standaloneMonths = calData.getStringArray("monthNames", "format", "wide");
        }

        try {
           standaloneShortMonths =
               calData.getStringArray("monthNames", "stand-alone", "abbreviated");
        }
        catch (MissingResourceException e) {
           standaloneShortMonths = calData.getStringArray("monthNames", "format", "abbreviated");
        }

        try {
           standaloneNarrowMonths = calData.getStringArray("monthNames", "stand-alone", "narrow");
        }
        catch (MissingResourceException e) {
           try {
              standaloneNarrowMonths = calData.getStringArray("monthNames", "format", "narrow");
           }
           catch (MissingResourceException e1) {
              standaloneNarrowMonths =
                  calData.getStringArray("monthNames", "format", "abbreviated");
           }
        }

        String[] lWeekdays = calData.getStringArray("dayNames", "wide");
        weekdays = new String[8];
        weekdays[0] = "";  // 1-based
        System.arraycopy(lWeekdays, 0, weekdays, 1, lWeekdays.length);

        String[] sWeekdays = calData.getStringArray("dayNames", "abbreviated");
        shortWeekdays = new String[8];
        shortWeekdays[0] = "";  // 1-based
        System.arraycopy(sWeekdays, 0, shortWeekdays, 1, sWeekdays.length);

        String [] nWeekdays = null;
        try {
           nWeekdays = calData.getStringArray("dayNames", "narrow");
        }
        catch (MissingResourceException e) {
            try {
                nWeekdays = calData.getStringArray("dayNames", "stand-alone", "narrow");
            }
            catch (MissingResourceException e1) {
                nWeekdays = calData.getStringArray("dayNames", "abbreviated");
            }
        }
        narrowWeekdays = new String[8];
        narrowWeekdays[0] = "";  // 1-based
        System.arraycopy(nWeekdays, 0, narrowWeekdays, 1, nWeekdays.length);

        String [] saWeekdays = null;
        try {
           saWeekdays = calData.getStringArray("dayNames", "stand-alone", "wide");
        }
        catch (MissingResourceException e) {
           saWeekdays = calData.getStringArray("dayNames", "format", "wide");
        }
        standaloneWeekdays = new String[8];
        standaloneWeekdays[0] = "";  // 1-based
        System.arraycopy(saWeekdays, 0, standaloneWeekdays, 1, saWeekdays.length);

        String [] ssWeekdays = null;
        try {
           ssWeekdays = calData.getStringArray("dayNames", "stand-alone", "abbreviated");
        }
        catch (MissingResourceException e) {
           ssWeekdays = calData.getStringArray("dayNames", "format", "abbreviated");
        }
        standaloneShortWeekdays = new String[8];
        standaloneShortWeekdays[0] = "";  // 1-based
        System.arraycopy(ssWeekdays, 0, standaloneShortWeekdays, 1, ssWeekdays.length);

        String [] snWeekdays = null;
        try {
           snWeekdays = calData.getStringArray("dayNames", "stand-alone", "narrow");
        }
        catch (MissingResourceException e) {
           try {
              snWeekdays = calData.getStringArray("dayNames", "format", "narrow");
           }
           catch (MissingResourceException e1) {
              snWeekdays = calData.getStringArray("dayNames", "format", "abbreviated");
           }
        }
        standaloneNarrowWeekdays = new String[8];
        standaloneNarrowWeekdays[0] = "";  // 1-based
        System.arraycopy(snWeekdays, 0, standaloneNarrowWeekdays, 1, snWeekdays.length);

        ampms = calData.getStringArray("AmPmMarkers");

        quarters = calData.getStringArray("quarters", "wide");
        shortQuarters = calData.getStringArray("quarters", "abbreviated");

        try {
           standaloneQuarters = calData.getStringArray("quarters", "stand-alone", "wide");
        }
        catch (MissingResourceException e) {
           standaloneQuarters = calData.getStringArray("quarters", "format", "wide");
        }

        try {
           standaloneShortQuarters = calData.getStringArray("quarters", "stand-alone", "abbreviated");
        }
        catch (MissingResourceException e) {
            standaloneShortQuarters = calData.getStringArray("quarters", "format", "abbreviated");
        }

        // Initialize localized GMT format patterns
        initializeGMTFormat(desiredLocale);

        requestedLocale = desiredLocale;

        ICUResourceBundle rb =
            (ICUResourceBundle)UResourceBundle.getBundleInstance(
                ICUResourceBundle.ICU_BASE_NAME, desiredLocale);

        // Because localized date/time pattern characters will be obsolete in CLDR,
        // we decided not to maintain localized pattern characters in ICU any more.
        // We always use the base pattern characters by default. (ticket#5597)

        //localPatternChars = rb.getString("localPatternChars");
        localPatternChars = patternChars;

        // TODO: obtain correct actual/valid locale later
        ULocale uloc = rb.getULocale();
        setLocale(uloc, uloc);
    }

    static final String DEFAULT_GMT_PATTERN = "GMT{0}";
    static final String[][] DEFAULT_GMT_HOUR_PATTERNS = {
        {"-HH:mm:ss", "-HH:mm"},
        {"+HH:mm:ss", "+HH:mm"}
    };

    /**
     * Initializes localized GMT format patterns
     */
    private void initializeGMTFormat(ULocale desiredLocale) {
        // TimeZone format localization is not included in CalendarData
        gmtFormat = ZoneMeta.getTZLocalizationInfo(desiredLocale, ZoneMeta.GMT);
        if (gmtFormat == null) {
            gmtFormat = DEFAULT_GMT_PATTERN;
        }

        try {
            String offsetHM = ZoneMeta.getTZLocalizationInfo(desiredLocale, ZoneMeta.HOUR);
            gmtHourFormats = new String[2][2];
            int sepIdx = offsetHM.indexOf(';');
            if (sepIdx != -1) {
                gmtHourFormats[OFFSET_POSITIVE][OFFSET_HM] = offsetHM.substring(0, sepIdx);
                gmtHourFormats[OFFSET_NEGATIVE][OFFSET_HM] = offsetHM.substring(sepIdx + 1);
            } else {
                gmtHourFormats[OFFSET_POSITIVE][OFFSET_HM] = "+HH:mm";
                gmtHourFormats[OFFSET_NEGATIVE][OFFSET_HM] = "-HH:mm";
            }
            // CLDR 1.5 does not have GMT offset pattern including second field.
            // For now, append "ss" to the end.
            if (gmtHourFormats[OFFSET_POSITIVE][OFFSET_HM].indexOf(':') != -1) {
                gmtHourFormats[OFFSET_POSITIVE][OFFSET_HMS] =
                    gmtHourFormats[OFFSET_POSITIVE][OFFSET_HM] + ":ss";
            } else if (gmtHourFormats[OFFSET_POSITIVE][OFFSET_HM].indexOf('.') != -1) {
                gmtHourFormats[OFFSET_POSITIVE][OFFSET_HMS] =
                    gmtHourFormats[OFFSET_POSITIVE][OFFSET_HM] + ".ss";
            } else {
                gmtHourFormats[OFFSET_POSITIVE][OFFSET_HMS] =
                    gmtHourFormats[OFFSET_POSITIVE][OFFSET_HM] + "ss";
            }
            if (gmtHourFormats[OFFSET_NEGATIVE][OFFSET_HM].indexOf(':') != -1) {
                gmtHourFormats[OFFSET_NEGATIVE][OFFSET_HMS] =
                    gmtHourFormats[OFFSET_NEGATIVE][OFFSET_HM] + ":ss";
            } else if (gmtHourFormats[OFFSET_NEGATIVE][OFFSET_HM].indexOf('.') != -1) {
                gmtHourFormats[OFFSET_NEGATIVE][OFFSET_HMS] =
                    gmtHourFormats[OFFSET_NEGATIVE][OFFSET_HM] + ".ss";
            } else {
                gmtHourFormats[OFFSET_NEGATIVE][OFFSET_HMS] =
                    gmtHourFormats[OFFSET_NEGATIVE][OFFSET_HM] + "ss";
            }
        } catch (MissingResourceException e) {
            gmtHourFormats = DEFAULT_GMT_HOUR_PATTERNS;
        }
    }

    private static final boolean arrayOfArrayEquals(Object[][] aa1, Object[][]aa2) {
        if (aa1 == aa2) { // both are null
            return true;
        }
        if (aa1 == null || aa2 == null) { // one is null and the other is not
            return false;
        }
        if (aa1.length != aa2.length) {
            return false;
        }
        boolean equal = true;
        for (int i = 0; i < aa1.length; i++) {
            equal = Utility.arrayEquals(aa1[i], aa2[i]);
            if (!equal) {
                break;
            }
        }
        return equal;
    }

    /**
     * Package local method (for now) to get localized GMT format pattern.
     */
    String getGmtFormat() {
        return gmtFormat;
    }

    static final int OFFSET_HMS = 0;
    static final int OFFSET_HM = 1;
    static final int OFFSET_NEGATIVE = 0;
    static final int OFFSET_POSITIVE = 1;

    /*
     * Package local method (for now) to get hour format pattern used by localized
     * GMT string.
     */
    String getGmtHourFormat(int sign, int width) {
        return gmtHourFormats[sign][width];
    }

    /*
     * Package local method to access ZoneStringFormat used by this
     * DateFormatSymbols instance.
     */
    ZoneStringFormat getZoneStringFormat() {
        if (zsformat != null) {
            return zsformat;
        }
        if (zoneStrings != null) {
            zsformat = new ZoneStringFormat(zoneStrings);
            return zsformat;
        }
        // We do not want to hold the reference to an instance of
        // ZoneStringFormat.  An instance of ZoneStringFormat for
        // a locale is shared and cached in ZoneStringFormat class
        // itself.
        return ZoneStringFormat.getInstance(requestedLocale);
    }

    /*
     * save the input locale
     */
    private ULocale requestedLocale;

    /*
     * Clones an array of Strings.
     * @param srcArray the source array to be cloned.
     * @return a cloned array.
     */
    private final String[] duplicate(String[] srcArray)
    {
        return srcArray.clone();
    }

    private final String[][] duplicate(String[][] srcArray)
    {
        String[][] aCopy = new String[srcArray.length][];
        for (int i = 0; i < srcArray.length; ++i)
            aCopy[i] = duplicate(srcArray[i]);
        return aCopy;
    }

    /*
     * Compares the equality of the two arrays of String.
     * @param current this String array.
     * @param other that String array.
    private final boolean equals(String[] current, String[] other)
    {
        int count = current.length;

        for (int i = 0; i < count; ++i)
            if (!current[i].equals(other[i]))
                return false;
        return true;
    }
     */

    //~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

    /**
     * Returns the {@link DateFormatSymbols} object that should be used to format a
     * calendar system's dates in the given locale.
     * <p>
     * <b>Subclassing:</b><br>
     * When creating a new Calendar subclass, you must create the
     * {@link ResourceBundle ResourceBundle}
     * containing its {@link DateFormatSymbols DateFormatSymbols} in a specific place.
     * The resource bundle name is based on the calendar's fully-specified
     * class name, with ".resources" inserted at the end of the package name
     * (just before the class name) and "Symbols" appended to the end.
     * For example, the bundle corresponding to "com.ibm.icu.util.HebrewCalendar"
     * is "com.ibm.icu.impl.data.HebrewCalendarSymbols".
     * <p>
     * Within the ResourceBundle, this method searches for five keys:
     * <ul>
     * <li><b>DayNames</b> -
     *      An array of strings corresponding to each possible
     *      value of the <code>DAY_OF_WEEK</code> field.  Even though
     *      <code>DAY_OF_WEEK</code> starts with <code>SUNDAY</code> = 1,
     *      This array is 0-based; the name for Sunday goes in the
     *      first position, at index 0.  If this key is not found
     *      in the bundle, the day names are inherited from the
     *      default <code>DateFormatSymbols</code> for the requested locale.
     *
     * <li><b>DayAbbreviations</b> -
     *      An array of abbreviated day names corresponding
     *      to the values in the "DayNames" array.  If this key
     *      is not found in the resource bundle, the "DayNames"
     *      values are used instead.  If neither key is found,
     *      the day abbreviations are inherited from the default
     *      <code>DateFormatSymbols</code> for the locale.
     *
     * <li><b>MonthNames</b> -
     *      An array of strings corresponding to each possible
     *      value of the <code>MONTH</code> field.  If this key is not found
     *      in the bundle, the month names are inherited from the
     *      default <code>DateFormatSymbols</code> for the requested locale.
     *
     * <li><b>MonthAbbreviations</b> -
     *      An array of abbreviated day names corresponding
     *      to the values in the "MonthNames" array.  If this key
     *      is not found in the resource bundle, the "MonthNames"
     *      values are used instead.  If neither key is found,
     *      the day abbreviations are inherited from the default
     *      <code>DateFormatSymbols</code> for the locale.
     *
     * <li><b>Eras</b> -
     *      An array of strings corresponding to each possible
     *      value of the <code>ERA</code> field.  If this key is not found
     *      in the bundle, the era names are inherited from the
     *      default <code>DateFormatSymbols</code> for the requested locale.
     * </ul>
     * <p>
     * @param cal       The calendar system whose date format symbols are desired.
     * @param locale    The locale whose symbols are desired.
     *
     * @see DateFormatSymbols#DateFormatSymbols(java.util.Locale)
     * @stable ICU 2.0
     */
    public DateFormatSymbols(Calendar cal, Locale locale) {
        initializeData(ULocale.forLocale(locale), cal.getType());
    }

    /**
     * Returns the {@link DateFormatSymbols} object that should be used to format a
     * calendar system's dates in the given locale.
     * <p>
     * <b>Subclassing:</b><br>
     * When creating a new Calendar subclass, you must create the
     * {@link ResourceBundle ResourceBundle}
     * containing its {@link DateFormatSymbols DateFormatSymbols} in a specific place.
     * The resource bundle name is based on the calendar's fully-specified
     * class name, with ".resources" inserted at the end of the package name
     * (just before the class name) and "Symbols" appended to the end.
     * For example, the bundle corresponding to "com.ibm.icu.util.HebrewCalendar"
     * is "com.ibm.icu.impl.data.HebrewCalendarSymbols".
     * <p>
     * Within the ResourceBundle, this method searches for five keys:
     * <ul>
     * <li><b>DayNames</b> -
     *      An array of strings corresponding to each possible
     *      value of the <code>DAY_OF_WEEK</code> field.  Even though
     *      <code>DAY_OF_WEEK</code> starts with <code>SUNDAY</code> = 1,
     *      This array is 0-based; the name for Sunday goes in the
     *      first position, at index 0.  If this key is not found
     *      in the bundle, the day names are inherited from the
     *      default <code>DateFormatSymbols</code> for the requested locale.
     *
     * <li><b>DayAbbreviations</b> -
     *      An array of abbreviated day names corresponding
     *      to the values in the "DayNames" array.  If this key
     *      is not found in the resource bundle, the "DayNames"
     *      values are used instead.  If neither key is found,
     *      the day abbreviations are inherited from the default
     *      <code>DateFormatSymbols</code> for the locale.
     *
     * <li><b>MonthNames</b> -
     *      An array of strings corresponding to each possible
     *      value of the <code>MONTH</code> field.  If this key is not found
     *      in the bundle, the month names are inherited from the
     *      default <code>DateFormatSymbols</code> for the requested locale.
     *
     * <li><b>MonthAbbreviations</b> -
     *      An array of abbreviated day names corresponding
     *      to the values in the "MonthNames" array.  If this key
     *      is not found in the resource bundle, the "MonthNames"
     *      values are used instead.  If neither key is found,
     *      the day abbreviations are inherited from the default
     *      <code>DateFormatSymbols</code> for the locale.
     *
     * <li><b>Eras</b> -
     *      An array of strings corresponding to each possible
     *      value of the <code>ERA</code> field.  If this key is not found
     *      in the bundle, the era names are inherited from the
     *      default <code>DateFormatSymbols</code> for the requested locale.
     * </ul>
     * <p>
     * @param cal       The calendar system whose date format symbols are desired.
     * @param locale    The ulocale whose symbols are desired.
     *
     * @see DateFormatSymbols#DateFormatSymbols(java.util.Locale)
     * @stable ICU 3.2
     */
    public DateFormatSymbols(Calendar cal, ULocale locale) {
        initializeData(locale, cal.getType());
    }

    /**
     * Variant of DateFormatSymbols(Calendar, Locale) that takes the Calendar class
     * instead of a Calandar instance.
     * @see #DateFormatSymbols(Calendar, Locale)
     * @stable ICU 2.2
     */
    public DateFormatSymbols(Class<? extends Calendar> calendarClass, Locale locale) {
        this(calendarClass, ULocale.forLocale(locale));
    }

    /**
     * Variant of DateFormatSymbols(Calendar, ULocale) that takes the Calendar class
     * instead of a Calandar instance.
     * @see #DateFormatSymbols(Calendar, Locale)
     * @stable ICU 3.2
     */
    public DateFormatSymbols(Class<? extends Calendar> calendarClass, ULocale locale) {
        String fullName = calendarClass.getName();
        int lastDot = fullName.lastIndexOf('.');
        String className = fullName.substring(lastDot+1);
        String calType = className.replaceAll("Calendar", "").toLowerCase();

        initializeData(locale, calType);
    }

    /**
     * Fetches a custom calendar's DateFormatSymbols out of the given resource
     * bundle.  Symbols that are not overridden are inherited from the
     * default DateFormatSymbols for the locale.
     * @see DateFormatSymbols#DateFormatSymbols(java.util.Locale)
     * @stable ICU 2.0
     */
    public DateFormatSymbols(ResourceBundle bundle, Locale locale) {
        this(bundle, ULocale.forLocale(locale));
    }

    /**
     * Fetches a custom calendar's DateFormatSymbols out of the given resource
     * bundle.  Symbols that are not overridden are inherited from the
     * default DateFormatSymbols for the locale.
     * @see DateFormatSymbols#DateFormatSymbols(java.util.Locale)
     * @stable ICU 3.2
     */
    public DateFormatSymbols(ResourceBundle bundle, ULocale locale) {
        initializeData(locale,
            new CalendarData((ICUResourceBundle)bundle, CalendarUtil.getCalendarType(locale)));
    }

    /**
     * Finds the ResourceBundle containing the date format information for
     * a specified calendar subclass in a given locale.
     * <p>
     * The resource bundle name is based on the calendar's fully-specified
     * class name, with ".resources" inserted at the end of the package name
     * (just before the class name) and "Symbols" appended to the end.
     * For example, the bundle corresponding to "com.ibm.icu.util.HebrewCalendar"
     * is "com.ibm.icu.impl.data.HebrewCalendarSymbols".
     * <p>
     * <b>Note:</b>Because of the structural changes in the ICU locale bundle,
     * this API no longer works as described.  This method always returns null.
     * @deprecated ICU 4.0
     */
    // This API was formerly @stable ICU 2.0
    static public ResourceBundle getDateFormatBundle(Class<? extends Calendar> calendarClass,
                                                     Locale locale)
        throws MissingResourceException {
        return null;
    }

    /**
     * Finds the ResourceBundle containing the date format information for
     * a specified calendar subclass in a given locale.
     * <p>
     * The resource bundle name is based on the calendar's fully-specified
     * class name, with ".resources" inserted at the end of the package name
     * (just before the class name) and "Symbols" appended to the end.
     * For example, the bundle corresponding to "com.ibm.icu.util.HebrewCalendar"
     * is "com.ibm.icu.impl.data.HebrewCalendarSymbols".
     * <p>
     * <b>Note:</b>Because of the structural changes in the ICU locale bundle,
     * this API no longer works as described.  This method always returns null.
     * @deprecated ICU 4.0
     */
    // This API was formerly @stable ICU 3.2
    static public ResourceBundle getDateFormatBundle(Class<? extends Calendar> calendarClass,
                                                     ULocale locale)
        throws MissingResourceException {
        return null;
    }

    /**
     * Variant of getDateFormatBundle(java.lang.Class, java.util.Locale) that takes
     * a Calendar instance instead of a Calendar class.
     * <p>
     * <b>Note:</b>Because of the structural changes in the ICU locale bundle,
     * this API no longer works as described.  This method always returns null.
     * @see #getDateFormatBundle(java.lang.Class, java.util.Locale)
     * @deprecated ICU 4.0
     */
    // This API was formerly @stable ICU 2.2
    public static ResourceBundle getDateFormatBundle(Calendar cal, Locale locale)
        throws MissingResourceException {
        return null;
    }

    /**
     * Variant of getDateFormatBundle(java.lang.Class, java.util.Locale) that takes
     * a Calendar instance instead of a Calendar class.
     * <p>
     * <b>Note:</b>Because of the structural changes in the ICU locale bundle,
     * this API no longer works as described.  This method always returns null.
     * @see #getDateFormatBundle(java.lang.Class, java.util.Locale)
     * @deprecated ICU 4.0
     */
    // This API was formerly @stable ICU 3.2
    public static ResourceBundle getDateFormatBundle(Calendar cal, ULocale locale)
        throws MissingResourceException {
        return null;
    }

    // -------- BEGIN ULocale boilerplate --------

    /**
     * Returns the locale that was used to create this object, or null.
     * This may may differ from the locale requested at the time of
     * this object's creation.  For example, if an object is created
     * for locale <tt>en_US_CALIFORNIA</tt>, the actual data may be
     * drawn from <tt>en</tt> (the <i>actual</i> locale), and
     * <tt>en_US</tt> may be the most specific locale that exists (the
     * <i>valid</i> locale).
     *
     * <p>Note: This method will be implemented in ICU 3.0; ICU 2.8
     * contains a partial preview implementation.  The * <i>actual</i>
     * locale is returned correctly, but the <i>valid</i> locale is
     * not, in most cases.
     * @param type type of information requested, either {@link
     * com.ibm.icu.util.ULocale#VALID_LOCALE} or {@link
     * com.ibm.icu.util.ULocale#ACTUAL_LOCALE}.
     * @return the information specified by <i>type</i>, or null if
     * this object was not constructed from locale data.
     * @see com.ibm.icu.util.ULocale
     * @see com.ibm.icu.util.ULocale#VALID_LOCALE
     * @see com.ibm.icu.util.ULocale#ACTUAL_LOCALE
     * @draft ICU 2.8 (retain)
     * @provisional This API might change or be removed in a future release.
     */
    public final ULocale getLocale(ULocale.Type type) {
        return type == ULocale.ACTUAL_LOCALE ?
            this.actualLocale : this.validLocale;
    }

    /**
     * Sets information about the locales that were used to create this
     * object.  If the object was not constructed from locale data,
     * both arguments should be set to null.  Otherwise, neither
     * should be null.  The actual locale must be at the same level or
     * less specific than the valid locale.  This method is intended
     * for use by factories or other entities that create objects of
     * this class.
     * @param valid the most specific locale containing any resource
     * data, or null
     * @param actual the locale containing data used to construct this
     * object, or null
     * @see com.ibm.icu.util.ULocale
     * @see com.ibm.icu.util.ULocale#VALID_LOCALE
     * @see com.ibm.icu.util.ULocale#ACTUAL_LOCALE
     */
    final void setLocale(ULocale valid, ULocale actual) {
        // Change the following to an assertion later
        if ((valid == null) != (actual == null)) {
            ///CLOVER:OFF
            throw new IllegalArgumentException();
            ///CLOVER:ON
        }
        // Another check we could do is that the actual locale is at
        // the same level or less specific than the valid locale.
        this.validLocale = valid;
        this.actualLocale = actual;
    }

    /**
     * The most specific locale containing any resource data, or null.
     * @see com.ibm.icu.util.ULocale
     */
    private ULocale validLocale;

    /**
     * The locale containing data used to construct this object, or
     * null.
     * @see com.ibm.icu.util.ULocale
     */
    private ULocale actualLocale;

    // -------- END ULocale boilerplate --------

    /**
     * 3.8 or older version did not have localized GMT format
     * patterns.
     */
    private void readObject(ObjectInputStream stream) throws IOException, ClassNotFoundException {
        stream.defaultReadObject();
        if (gmtFormat == null) {
            initializeGMTFormat(requestedLocale);
        }
    }
}