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 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.

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 * 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.

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 * 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

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package sun.util.locale.provider;

import java.text.spi.BreakIteratorProvider;

import java.text.spi.CollatorProvider;

import java.text.spi.DateFormatProvider;

import java.text.spi.DateFormatSymbolsProvider;

import java.text.spi.DecimalFormatSymbolsProvider;

import java.text.spi.NumberFormatProvider;

import java.util.ArrayList;

import java.util.Collections;

import java.util.List;

import java.util.Locale;

import java.util.Map;

import java.util.ResourceBundle;

import java.util.Set;

import java.util.concurrent.ConcurrentHashMap;

import java.util.concurrent.ConcurrentMap;

import java.util.spi.CalendarDataProvider;

import java.util.spi.CalendarNameProvider;

import java.util.spi.CurrencyNameProvider;

import java.util.spi.LocaleNameProvider;

import java.util.spi.LocaleServiceProvider;

import java.util.spi.TimeZoneNameProvider;

import sun.security.action.GetPropertyAction;

import sun.text.spi.JavaTimeDateTimePatternProvider;

import sun.util.spi.CalendarProvider;

/**

 * The LocaleProviderAdapter abstract class.

 *

 * @author Naoto Sato

 * @author Masayoshi Okutsu

 */

public abstract class LocaleProviderAdapter {

    /**

     * Adapter type.

     */

    public static enum Type {

        JRE("sun.util.locale.provider.JRELocaleProviderAdapter", "sun.util.resources", "sun.text.resources"),

        CLDR("sun.util.cldr.CLDRLocaleProviderAdapter", "sun.util.resources.cldr", "sun.text.resources.cldr"),

        SPI("sun.util.locale.provider.SPILocaleProviderAdapter"),

        HOST("sun.util.locale.provider.HostLocaleProviderAdapter"),

        FALLBACK("sun.util.locale.provider.FallbackLocaleProviderAdapter", "sun.util.resources", "sun.text.resources");

        private final String CLASSNAME;

        private final String UTIL_RESOURCES_PACKAGE;

        private final String TEXT_RESOURCES_PACKAGE;

        private Type(String className) {

            this(className, null, null);

        }

        private Type(String className, String util, String text) {

            CLASSNAME = className;

            UTIL_RESOURCES_PACKAGE = util;

            TEXT_RESOURCES_PACKAGE = text;

        }

        public String getAdapterClassName() {

            return CLASSNAME;

        }

        public String getUtilResourcesPackage() {

            return UTIL_RESOURCES_PACKAGE;

        }

        public String getTextResourcesPackage() {

            return TEXT_RESOURCES_PACKAGE;

        }

    }

    /**

     * LocaleProviderAdapter preference list.

     */

    private static final List<Type> adapterPreference;

    /**

     * LocaleProviderAdapter instances

     */

    private static final Map<Type, LocaleProviderAdapter> adapterInstances = new ConcurrentHashMap<>();

    /**

     * Default fallback adapter type, which should return something meaningful in any case.

     * This is either CLDR or FALLBACK.

     */

    static volatile LocaleProviderAdapter.Type defaultLocaleProviderAdapter;

    /**

     * Adapter lookup cache.

     */

    private static ConcurrentMap<Class<? extends LocaleServiceProvider>, ConcurrentMap<Locale, LocaleProviderAdapter>>

        adapterCache = new ConcurrentHashMap<>();

    static {

        String order = GetPropertyAction.privilegedGetProperty("java.locale.providers");

        List<Type> typeList = new ArrayList<>();

        // Check user specified adapter preference

        if (order != null && !order.isEmpty()) {

            String[] types = order.split(",");

            for (String type : types) {

                type = type.trim().toUpperCase(Locale.ROOT);

                if (type.equals("COMPAT")) {

                    type = "JRE";

                }

                try {

                    Type aType = Type.valueOf(type.trim().toUpperCase(Locale.ROOT));

                    if (!typeList.contains(aType)) {

                        typeList.add(aType);

                    }

                } catch (IllegalArgumentException | UnsupportedOperationException e) {

                    // could be caused by the user specifying wrong

                    // provider name or format in the system property

                    LocaleServiceProviderPool.config(LocaleProviderAdapter.class, e.toString());

                }

            }

        }

        defaultLocaleProviderAdapter = Type.CLDR;

        if (!typeList.isEmpty()) {

            // bona fide preference exists

            if (!(typeList.contains(Type.CLDR) || (typeList.contains(Type.JRE)))) {

                // Append FALLBACK as the last resort when no ResourceBundleBasedAdapter is available.

                typeList.add(Type.FALLBACK);

                defaultLocaleProviderAdapter = Type.FALLBACK;

            }

        } else {

            // Default preference list.

            typeList.add(Type.CLDR);

            typeList.add(Type.JRE);

        }

        adapterPreference = Collections.unmodifiableList(typeList);

    }

    /**

     * Returns the singleton instance for each adapter type

     */

    public static LocaleProviderAdapter forType(Type type) {

        switch (type) {

        case JRE:

        case CLDR:

        case SPI:

        case HOST:

        case FALLBACK:

            LocaleProviderAdapter adapter = null;

            LocaleProviderAdapter cached = adapterInstances.get(type);

            if (cached == null) {

                try {

                    // lazily load adapters here

                    @SuppressWarnings("deprecation")

                    Object tmp = Class.forName(type.getAdapterClassName()).newInstance();

                    adapter = (LocaleProviderAdapter)tmp;

                    cached = adapterInstances.putIfAbsent(type, adapter);

                    if (cached != null) {

                        adapter = cached;

                    }

                } catch (ClassNotFoundException |

                         IllegalAccessException |

                         InstantiationException |

                         UnsupportedOperationException e) {

                    LocaleServiceProviderPool.config(LocaleProviderAdapter.class, e.toString());

                    adapterInstances.putIfAbsent(type, NONEXISTENT_ADAPTER);

                    if (defaultLocaleProviderAdapter == type) {

                        defaultLocaleProviderAdapter = Type.FALLBACK;

                    }

                }

            } else if (cached != NONEXISTENT_ADAPTER) {

                adapter = cached;

            }

            return adapter;

        default:

            throw new InternalError("unknown locale data adapter type");

        }

    }

    public static LocaleProviderAdapter forJRE() {

        return forType(Type.JRE);

    }

    public static LocaleProviderAdapter getResourceBundleBased() {

        for (Type type : getAdapterPreference()) {

            if (type == Type.JRE || type == Type.CLDR || type == Type.FALLBACK) {

                LocaleProviderAdapter adapter = forType(type);

                if (adapter != null) {

                    return adapter;

                }

            }

        }

        // Shouldn't happen.

        throw new InternalError();

    }

    /**

     * Returns the preference order of LocaleProviderAdapter.Type

     */

    public static List<Type> getAdapterPreference() {

        return adapterPreference;

    }

    /**

     * Returns a LocaleProviderAdapter for the given locale service provider that

     * best matches the given locale. This method returns the LocaleProviderAdapter

     * for JRE if none is found for the given locale.

     *

     * @param providerClass the class for the locale service provider

     * @param locale the desired locale.

     * @return a LocaleProviderAdapter

     */

    public static LocaleProviderAdapter getAdapter(Class<? extends LocaleServiceProvider> providerClass,

                                               Locale locale) {

        LocaleProviderAdapter adapter;

        // cache lookup

        ConcurrentMap<Locale, LocaleProviderAdapter> adapterMap = adapterCache.get(providerClass);

        if (adapterMap != null) {

            if ((adapter = adapterMap.get(locale)) != null) {

                return adapter;

            }

        } else {

            adapterMap = new ConcurrentHashMap<>();

            adapterCache.putIfAbsent(providerClass, adapterMap);

        }

        // Fast look-up for the given locale

        adapter = findAdapter(providerClass, locale);

        if (adapter != null) {

            adapterMap.putIfAbsent(locale, adapter);

            return adapter;

        }

        // Try finding an adapter in the normal candidate locales path of the given locale.

        List<Locale> lookupLocales = ResourceBundle.Control.getControl(ResourceBundle.Control.FORMAT_DEFAULT)

                                        .getCandidateLocales("", locale);

        for (Locale loc : lookupLocales) {

            if (loc.equals(locale)) {

                // We've already done with this loc.

                continue;

            }

            adapter = findAdapter(providerClass, loc);

            if (adapter != null) {

                adapterMap.putIfAbsent(locale, adapter);

                return adapter;

            }

        }

        // returns the adapter for FALLBACK as the last resort

        adapterMap.putIfAbsent(locale, forType(Type.FALLBACK));

        return forType(Type.FALLBACK);

    }

    private static LocaleProviderAdapter findAdapter(Class<? extends LocaleServiceProvider> providerClass,

                                                 Locale locale) {

        for (Type type : getAdapterPreference()) {

            LocaleProviderAdapter adapter = forType(type);

            if (adapter != null) {

                LocaleServiceProvider provider = adapter.getLocaleServiceProvider(providerClass);

                if (provider != null) {

                    if (provider.isSupportedLocale(locale)) {

                        return adapter;

                    }

                }

            }

        }

        return null;

    }

    /**

     * A utility method for implementing the default LocaleServiceProvider.isSupportedLocale

     * for the JRE, CLDR, and FALLBACK adapters.

     */

    public boolean isSupportedProviderLocale(Locale locale,  Set<String> langtags) {

        LocaleProviderAdapter.Type type = getAdapterType();

        assert type == Type.JRE || type == Type.CLDR || type == Type.FALLBACK;

        return false;

    }

    public static Locale[] toLocaleArray(Set<String> tags) {

        Locale[] locs = new Locale[tags.size() + 1];

        int index = 0;

        locs[index++] = Locale.ROOT;

        for (String tag : tags) {

            switch (tag) {

            case "ja-JP-JP":

                locs[index++] = JRELocaleConstants.JA_JP_JP;

                break;

            case "th-TH-TH":

                locs[index++] = JRELocaleConstants.TH_TH_TH;

                break;

            default:

                locs[index++] = Locale.forLanguageTag(tag);

                break;

            }

        }

        return locs;

    }

    /**

     * Returns the type of this LocaleProviderAdapter

     */

    public abstract LocaleProviderAdapter.Type getAdapterType();

    /**

     * Getter method for Locale Service Providers.

     */

    public abstract <P extends LocaleServiceProvider> P getLocaleServiceProvider(Class<P> c);

    /**

     * Returns a BreakIteratorProvider for this LocaleProviderAdapter, or null if no

     * BreakIteratorProvider is available.

     *

     * @return a BreakIteratorProvider

     */

    public abstract BreakIteratorProvider getBreakIteratorProvider();

    /**

     * Returns a ollatorProvider for this LocaleProviderAdapter, or null if no

     * ollatorProvider is available.

     *

     * @return a ollatorProvider

     */

    public abstract CollatorProvider getCollatorProvider();

    /**

     * Returns a DateFormatProvider for this LocaleProviderAdapter, or null if no

     * DateFormatProvider is available.

     *

     * @return a DateFormatProvider

     */

    public abstract DateFormatProvider getDateFormatProvider();

    /**

     * Returns a DateFormatSymbolsProvider for this LocaleProviderAdapter, or null if no

     * DateFormatSymbolsProvider is available.

     *

     * @return a DateFormatSymbolsProvider

     */

    public abstract DateFormatSymbolsProvider getDateFormatSymbolsProvider();

    /**

     * Returns a DecimalFormatSymbolsProvider for this LocaleProviderAdapter, or null if no

     * DecimalFormatSymbolsProvider is available.

     *

     * @return a DecimalFormatSymbolsProvider

     */

    public abstract DecimalFormatSymbolsProvider getDecimalFormatSymbolsProvider();

    /**

     * Returns a NumberFormatProvider for this LocaleProviderAdapter, or null if no

     * NumberFormatProvider is available.

     *

     * @return a NumberFormatProvider

     */

    public abstract NumberFormatProvider getNumberFormatProvider();

    /*

     * Getter methods for java.util.spi.* providers

     */

    /**

     * Returns a CurrencyNameProvider for this LocaleProviderAdapter, or null if no

     * CurrencyNameProvider is available.

     *

     * @return a CurrencyNameProvider

     */

    public abstract CurrencyNameProvider getCurrencyNameProvider();

    /**

     * Returns a LocaleNameProvider for this LocaleProviderAdapter, or null if no

     * LocaleNameProvider is available.

     *

     * @return a LocaleNameProvider

     */

    public abstract LocaleNameProvider getLocaleNameProvider();

    /**

     * Returns a TimeZoneNameProvider for this LocaleProviderAdapter, or null if no

     * TimeZoneNameProvider is available.

     *

     * @return a TimeZoneNameProvider

     */

    public abstract TimeZoneNameProvider getTimeZoneNameProvider();

    /**

     * Returns a CalendarDataProvider for this LocaleProviderAdapter, or null if no

     * CalendarDataProvider is available.

     *

     * @return a CalendarDataProvider

     */

    public abstract CalendarDataProvider getCalendarDataProvider();

    /**

     * Returns a CalendarNameProvider for this LocaleProviderAdapter, or null if no

     * CalendarNameProvider is available.

     *

     * @return a CalendarNameProvider

     */

    public abstract CalendarNameProvider getCalendarNameProvider();

    /**

     * Returns a CalendarProvider for this LocaleProviderAdapter, or null if no

     * CalendarProvider is available.

     *

     * @return a CalendarProvider

     */

    public abstract CalendarProvider getCalendarProvider();

    /**

     * Returns a JavaTimeDateTimePatternProvider for this LocaleProviderAdapter,

     * or null if no JavaTimeDateTimePatternProvider is available.

     *

     * @return a JavaTimeDateTimePatternProvider

     */

    public abstract JavaTimeDateTimePatternProvider getJavaTimeDateTimePatternProvider();

    public abstract LocaleResources getLocaleResources(Locale locale);

    public abstract Locale[] getAvailableLocales();

    private static final LocaleProviderAdapter NONEXISTENT_ADAPTER = new NonExistentAdapter();

    private static final class NonExistentAdapter extends FallbackLocaleProviderAdapter {

        @Override

        public LocaleProviderAdapter.Type getAdapterType() {

            return null;

        }

        private NonExistentAdapter() {};

    }

}