https://openjdk.java.net/ 
/*
 * Copyright (c) 2012, 2018, 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.
 */

package sun.util.locale.provider;

import java.util.Locale;
import java.util.Objects;
import java.util.Set;
import java.util.TimeZone;
import java.util.spi.TimeZoneNameProvider;


Concrete implementation of the TimeZoneNameProvider class for the JRE LocaleProviderAdapter. 
Author:Naoto Sato, Masayoshi Okutsu
/**
 * Concrete implementation of the
 * {@link java.util.spi.TimeZoneNameProvider TimeZoneNameProvider} class
 * for the JRE LocaleProviderAdapter.
 *
 * @author Naoto Sato
 * @author Masayoshi Okutsu
 */
public class TimeZoneNameProviderImpl extends TimeZoneNameProvider {
    private final LocaleProviderAdapter.Type type;
    private final Set<String> langtags;

    protected TimeZoneNameProviderImpl(LocaleProviderAdapter.Type type, Set<String> langtags) {
        this.type = type;
        this.langtags = langtags;
    }

    
Returns an array of all locales for which this locale service provider
can provide localized objects or names.

Returns:An array of all locales for which this locale service provider
can provide localized objects or names.
/**
     * Returns an array of all locales for which this locale service provider
     * can provide localized objects or names.
     *
     * @return An array of all locales for which this locale service provider
     * can provide localized objects or names.
     */
    @Override
    public Locale[] getAvailableLocales() {
        return LocaleProviderAdapter.toLocaleArray(langtags);
    }

    @Override
    public boolean isSupportedLocale(Locale locale) {
        return LocaleProviderAdapter.forType(type).isSupportedProviderLocale(locale, langtags);
    }

    
Returns a name for the given time zone ID that's suitable for
presentation to the user in the specified locale. The given time
zone ID is "GMT" or one of the names defined using "Zone" entries
in the "tz database", a public domain time zone database at
ftp://elsie.nci.nih.gov/pub/.
The data of this database is contained in a file whose name starts with
"tzdata", and the specification of the data format is part of the zic.8
man page, which is contained in a file whose name starts with "tzcode".


If daylight is true, the method should return a name
appropriate for daylight saving time even if the specified time zone
has not observed daylight saving time in the past.

Params:
  • id – a time zone ID string
  • daylight – if true, return the daylight saving name.
  • style – either TimeZone.LONG or TimeZone.SHORT
  • locale – the desired locale
Throws:
See Also:
Returns:the human-readable name of the given time zone in the
    given locale, or null if it's not available.
/**
     * Returns a name for the given time zone ID that's suitable for
     * presentation to the user in the specified locale. The given time
     * zone ID is "GMT" or one of the names defined using "Zone" entries
     * in the "tz database", a public domain time zone database at
     * <a href="ftp://elsie.nci.nih.gov/pub/">ftp://elsie.nci.nih.gov/pub/</a>.
     * The data of this database is contained in a file whose name starts with
     * "tzdata", and the specification of the data format is part of the zic.8
     * man page, which is contained in a file whose name starts with "tzcode".
     * <p>
     * If <code>daylight</code> is true, the method should return a name
     * appropriate for daylight saving time even if the specified time zone
     * has not observed daylight saving time in the past.
     *
     * @param id a time zone ID string
     * @param daylight if true, return the daylight saving name.
     * @param style either {@link java.util.TimeZone#LONG TimeZone.LONG} or
     *    {@link java.util.TimeZone#SHORT TimeZone.SHORT}
     * @param locale the desired locale
     * @return the human-readable name of the given time zone in the
     *     given locale, or null if it's not available.
     * @exception IllegalArgumentException if <code>style</code> is invalid,
     *     or <code>locale</code> isn't one of the locales returned from
     *     {@link java.util.spi.LocaleServiceProvider#getAvailableLocales()
     *     getAvailableLocales()}.
     * @exception NullPointerException if <code>ID</code> or <code>locale</code>
     *     is null
     * @see java.util.TimeZone#getDisplayName(boolean, int, java.util.Locale)
     */
    @Override
    public String getDisplayName(String id, boolean daylight, int style, Locale locale) {
        String[] names = getDisplayNameArray(id, locale);
        if (Objects.nonNull(names)) {
            assert names.length >= 7;
            int index = daylight ? 3 : 1;
            if (style == TimeZone.SHORT) {
                index++;
            }
            return names[index];
        }
        return null;
    }

    @Override
    public String getGenericDisplayName(String id, int style, Locale locale) {
        String[] names = getDisplayNameArray(id, locale);
        if (Objects.nonNull(names)) {
            assert names.length >= 7;
            return names[(style == TimeZone.LONG) ? 5 : 6];
        }
        return null;
    }

    protected String[] getDisplayNameArray(String id, Locale locale) {
        Objects.requireNonNull(id);
        Objects.requireNonNull(locale);

        return (String []) LocaleProviderAdapter.forType(type)
            .getLocaleResources(locale)
            .getTimeZoneNames(id);
    }

    
Returns a String[][] as the DateFormatSymbols.getZoneStrings() value for
the given locale.

Params:
  • locale – a Locale for time zone names
Returns:an array of time zone names arrays
/**
     * Returns a String[][] as the DateFormatSymbols.getZoneStrings() value for
     * the given locale.
     *
     * @param locale a Locale for time zone names
     * @return an array of time zone names arrays
     */
    protected String[][] getZoneStrings(Locale locale) {
        return LocaleProviderAdapter.forType(type).getLocaleResources(locale).getZoneStrings();
    }
}