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 * This code is distributed in the hope that it will be useful, but WITHOUT

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 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License

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 * accompanied this code).

 *

 * You should have received a copy of the GNU General Public License version

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package sun.util.locale.provider;

import java.util.ArrayList;

import java.util.Arrays;

import java.util.Collections;

import java.util.HashSet;

import java.util.IllformedLocaleException;

import java.util.List;

import java.util.Locale;

import java.util.Locale.Builder;

import java.util.ResourceBundle.Control;

import java.util.Set;

import java.util.concurrent.ConcurrentHashMap;

import java.util.concurrent.ConcurrentMap;

import java.util.spi.LocaleServiceProvider;

import sun.util.logging.PlatformLogger;

/**

 * An instance of this class holds a set of the third party implementations of a particular

 * locale sensitive service, such as {@link java.util.spi.LocaleNameProvider}.

 *

 * @author Naoto Sato

 * @author Masayoshi Okutsu

 */

public final class LocaleServiceProviderPool {

    /**

     * A Map that holds singleton instances of this class.  Each instance holds a

     * set of provider implementations of a particular locale sensitive service.

     */

    private static final ConcurrentMap<Class<? extends LocaleServiceProvider>, LocaleServiceProviderPool> poolOfPools =

        new ConcurrentHashMap<>();

    /**

     * A Map that retains Locale->provider mapping

     */

    private final ConcurrentMap<Locale, List<LocaleServiceProvider>> providersCache =

        new ConcurrentHashMap<>();

    /**

     * Available locales for this locale sensitive service.  This also contains

     * JRE's available locales

     */

    private Set<Locale> availableLocales = null;

    /**

     * Provider class

     */

    private final Class<? extends LocaleServiceProvider> providerClass;

    /**

     * Array of all Locale Sensitive SPI classes.

     *

     * We know "spiClasses" contains classes that extends LocaleServiceProvider,

     * but generic array creation is not allowed, thus the "unchecked" warning

     * is suppressed here.

     */

    @SuppressWarnings("unchecked")

    static final Class<LocaleServiceProvider>[] spiClasses =

                (Class<LocaleServiceProvider>[]) new Class<?>[] {

        java.text.spi.BreakIteratorProvider.class,

        java.text.spi.CollatorProvider.class,

        java.text.spi.DateFormatProvider.class,

        java.text.spi.DateFormatSymbolsProvider.class,

        java.text.spi.DecimalFormatSymbolsProvider.class,

        java.text.spi.NumberFormatProvider.class,

        java.util.spi.CurrencyNameProvider.class,

        java.util.spi.LocaleNameProvider.class,

        java.util.spi.TimeZoneNameProvider.class,

        java.util.spi.CalendarDataProvider.class

    };

    /**

     * A factory method that returns a singleton instance

     */

    public static LocaleServiceProviderPool getPool(Class<? extends LocaleServiceProvider> providerClass) {

        LocaleServiceProviderPool pool = poolOfPools.get(providerClass);

        if (pool == null) {

            LocaleServiceProviderPool newPool =

                new LocaleServiceProviderPool(providerClass);

            pool = poolOfPools.putIfAbsent(providerClass, newPool);

            if (pool == null) {

                pool = newPool;

            }

        }

        return pool;

    }

    /**

     * The sole constructor.

     *

     * @param c class of the locale sensitive service

     */

    private LocaleServiceProviderPool (final Class<? extends LocaleServiceProvider> c) {

        providerClass = c;

    }

    static void config(Class<? extends Object> caller, String message) {

        PlatformLogger logger = PlatformLogger.getLogger(caller.getCanonicalName());

        logger.config(message);

    }

    /**

     * Lazy loaded set of available locales.

     * Loading all locales is a very long operation.

     */

    private static class AllAvailableLocales {

        /**

         * Available locales for all locale sensitive services.

         * This also contains JRE's available locales

         */

        static final Locale[] allAvailableLocales;

        static {

            Set<Locale> all = new HashSet<>();

            for (Class<? extends LocaleServiceProvider> c : spiClasses) {

                LocaleServiceProviderPool pool =

                    LocaleServiceProviderPool.getPool(c);

                all.addAll(pool.getAvailableLocaleSet());

            }

            allAvailableLocales = all.toArray(new Locale[0]);

        }

        // No instantiation

        private AllAvailableLocales() {

        }

    }

    /**

     * Returns an array of available locales for all the provider classes.

     * This array is a merged array of all the locales that are provided by each

     * provider, including the JRE.

     *

     * @return an array of the available locales for all provider classes

     */

    public static Locale[] getAllAvailableLocales() {

        return AllAvailableLocales.allAvailableLocales.clone();

    }

    /**

     * Returns an array of available locales.  This array is a

     * merged array of all the locales that are provided by each

     * provider, including the JRE.

     *

     * @return an array of the available locales

     */

    public Locale[] getAvailableLocales() {

        Set<Locale> locList = new HashSet<>();

        locList.addAll(getAvailableLocaleSet());

        // Make sure it all contains JRE's locales for compatibility.

        locList.addAll(Arrays.asList(LocaleProviderAdapter.forJRE().getAvailableLocales()));

        Locale[] tmp = new Locale[locList.size()];

        locList.toArray(tmp);

        return tmp;

    }

    /**

     * Returns the union of locale sets that are available from

     * each service provider. This method does NOT return the

     * defensive copy.

     *

     * @return a set of available locales

     */

    private synchronized Set<Locale> getAvailableLocaleSet() {

        if (availableLocales == null) {

            availableLocales = new HashSet<>();

            for (LocaleProviderAdapter.Type type : LocaleProviderAdapter.getAdapterPreference()) {

                LocaleProviderAdapter lda = LocaleProviderAdapter.forType(type);

                if (lda != null) {

                    LocaleServiceProvider lsp = lda.getLocaleServiceProvider(providerClass);

                    if (lsp != null) {

                        Locale[] locales = lsp.getAvailableLocales();

                        for (Locale locale: locales) {

                            availableLocales.add(getLookupLocale(locale));

                        }

                    }

                }

            }

        }

        return availableLocales;

    }

    /**

     * Returns the provider's localized object for the specified

     * locale.

     *

     * @param getter an object on which getObject() method

     *     is called to obtain the provider's instance.

     * @param locale the given locale that is used as the starting one

     * @param params provider specific parameters

     * @return provider's instance, or null.

     */

    public <P extends LocaleServiceProvider, S> S getLocalizedObject(LocalizedObjectGetter<P, S> getter,

                                     Locale locale,

                                     Object... params) {

        return getLocalizedObjectImpl(getter, locale, true, null, params);

    }

    /**

     * Returns the provider's localized name for the specified

     * locale.

     *

     * @param getter an object on which getObject() method

     *     is called to obtain the provider's instance.

     * @param locale the given locale that is used as the starting one

     * @param key the key string for name providers

     * @param params provider specific parameters

     * @return provider's instance, or null.

     */

    public <P extends LocaleServiceProvider, S> S getLocalizedObject(LocalizedObjectGetter<P, S> getter,

                                     Locale locale,

                                     String key,

                                     Object... params) {

        return getLocalizedObjectImpl(getter, locale, false, key, params);

    }

    /**

     * Returns the provider's localized name for the specified

     * locale.

     *

     * @param getter an object on which getObject() method

     *     is called to obtain the provider's instance.

     * @param locale the given locale that is used as the starting one

     * @param isObjectProvider flag designating object provder or not

     * @param key the key string for name providers

     * @param params provider specific parameters

     * @return provider's instance, or null.

     */

    public <P extends LocaleServiceProvider, S> S getLocalizedObject(LocalizedObjectGetter<P, S> getter,

                                     Locale locale,

                                     Boolean isObjectProvider,

                                     String key,

                                     Object... params) {

        return getLocalizedObjectImpl(getter, locale, isObjectProvider, key, params);

    }

    @SuppressWarnings("unchecked")

    private <P extends LocaleServiceProvider, S> S getLocalizedObjectImpl(LocalizedObjectGetter<P, S> getter,

                                     Locale locale,

                                     boolean isObjectProvider,

                                     String key,

                                     Object... params) {

        if (locale == null) {

            throw new NullPointerException();

        }

        List<Locale> lookupLocales = getLookupLocales(locale);

        for (Locale current : lookupLocales) {

            S providersObj;

            for (LocaleServiceProvider lsp: findProviders(current, isObjectProvider)) {

                providersObj = getter.getObject((P)lsp, locale, key, params);

                if (providersObj != null) {

                    return providersObj;

                } else if (isObjectProvider) {

                    config(LocaleServiceProviderPool.class,

                }

            }

        }

        // not found.

        return null;

    }

    /**

     * Returns the list of locale service provider instances that support

     * the specified locale.

     *

     * @param locale the given locale

     * @return the list of locale data adapter types

     */

    private List<LocaleServiceProvider> findProviders(Locale locale, boolean isObjectProvider) {

        List<LocaleServiceProvider> providersList = providersCache.get(locale);

        if (providersList == null) {

            for (LocaleProviderAdapter.Type type : LocaleProviderAdapter.getAdapterPreference()) {

                LocaleProviderAdapter lda = LocaleProviderAdapter.forType(type);

                if (lda != null) {

                    LocaleServiceProvider lsp = lda.getLocaleServiceProvider(providerClass);

                    if (lsp != null) {

                        if (lsp.isSupportedLocale(locale)) {

                            if (providersList == null) {

                                providersList = new ArrayList<>(2);

                            }

                            providersList.add(lsp);

                            if (isObjectProvider) {

                                break;

                            }

                        }

                    }

                }

            }

            if (providersList == null) {

                providersList = NULL_LIST;

            }

            List<LocaleServiceProvider> val = providersCache.putIfAbsent(locale, providersList);

            if (val != null) {

                providersList = val;

            }

        }

        return providersList;

    }

    /**

     * Returns a list of candidate locales for service look up.

     * @param locale the input locale

     * @return the list of candidate locales for the given locale

     */

    static List<Locale> getLookupLocales(Locale locale) {

        // Note: We currently use the default implementation of

        // ResourceBundle.Control.getCandidateLocales. The result

        // returned by getCandidateLocales are already normalized

        // (no extensions) for service look up.

        List<Locale> lookupLocales = Control.getNoFallbackControl(Control.FORMAT_DEFAULT)

                                            .getCandidateLocales("", locale);

        return lookupLocales;

    }

    /**

     * Returns an instance of Locale used for service look up.

     * The result Locale has no extensions except for ja_JP_JP

     * and th_TH_TH

     *

     * @param locale the locale

     * @return the locale used for service look up

     */

    static Locale getLookupLocale(Locale locale) {

        Locale lookupLocale = locale;

        if (locale.hasExtensions()

                && !locale.equals(JRELocaleConstants.JA_JP_JP)

                && !locale.equals(JRELocaleConstants.TH_TH_TH)) {

            // remove extensions

            Builder locbld = new Builder();

            try {

                locbld.setLocale(locale);

                locbld.clearExtensions();

                lookupLocale = locbld.build();

            } catch (IllformedLocaleException e) {

                // A Locale with non-empty extensions

                // should have well-formed fields except

                // for ja_JP_JP and th_TH_TH. Therefore,

                // it should never enter in this catch clause.

                config(LocaleServiceProviderPool.class,

                       "A locale(" + locale + ") has non-empty extensions, but has illformed fields.");

                // Fallback - script field will be lost.

                lookupLocale = new Locale(locale.getLanguage(), locale.getCountry(), locale.getVariant());

            }

        }

        return lookupLocale;

    }

    /**

     * A dummy locale service provider list that indicates there is no

     * provider available

     */

    private static final List<LocaleServiceProvider> NULL_LIST =

        Collections.emptyList();

    /**

     * An interface to get a localized object for each locale sensitive

     * service class.

     */

    public interface LocalizedObjectGetter<P extends LocaleServiceProvider, S> {

        /**

         * Returns an object from the provider

         *

         * @param lsp the provider

         * @param locale the locale

         * @param key key string to localize, or null if the provider is not

         *     a name provider

         * @param params provider specific params

         * @return localized object from the provider

         */

        public S getObject(P lsp,

                           Locale locale,

                           String key,

                           Object... params);

    }

}