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	/*
	* Copyright (c) 1996, 2021, 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
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	/*
	* (C) Copyright Taligent, Inc. 1996, 1997 - All Rights Reserved
	* (C) Copyright IBM Corp. 1996 - 1998 - All Rights Reserved
	*
	* The original version of this source code and documentation
	* is copyrighted and owned by Taligent, Inc., a wholly-owned
	* subsidiary of IBM. These materials are provided under terms
	* of a License Agreement between Taligent and Sun. This technology
	* is protected by multiple US and International patents.
	*
	* This notice and attribution to Taligent may not be removed.
	* Taligent is a registered trademark of Taligent, Inc.
	*
	*/

	package java.util;

	import java.io.IOException;
	import java.io.ObjectInputStream;
	import java.io.ObjectOutputStream;
	import java.io.ObjectStreamField;
	import java.io.Serializable;
	import java.text.MessageFormat;
	import java.util.concurrent.ConcurrentHashMap;
	import java.util.spi.LocaleNameProvider;
	import java.util.stream.Collectors;

	import sun.security.action.GetPropertyAction;
	import sun.util.locale.BaseLocale;
	import sun.util.locale.InternalLocaleBuilder;
	import sun.util.locale.LanguageTag;
	import sun.util.locale.LocaleExtensions;
	import sun.util.locale.LocaleMatcher;
	import sun.util.locale.LocaleObjectCache;
	import sun.util.locale.LocaleSyntaxException;
	import sun.util.locale.LocaleUtils;
	import sun.util.locale.ParseStatus;
	import sun.util.locale.provider.LocaleProviderAdapter;
	import sun.util.locale.provider.LocaleResources;
	import sun.util.locale.provider.LocaleServiceProviderPool;
	import sun.util.locale.provider.TimeZoneNameUtility;

	/**
	* A {@code Locale} object represents a specific geographical, political,
	* or cultural region. An operation that requires a {@code Locale} to perform
	* its task is called <em>locale-sensitive</em> and uses the {@code Locale}
	* to tailor information for the user. For example, displaying a number
	* is a locale-sensitive operation— the number should be formatted
	* according to the customs and conventions of the user's native country,
	* region, or culture.
	*
	* <p> The {@code Locale} class implements IETF BCP 47 which is composed of
	* <a href="http://tools.ietf.org/html/rfc4647">RFC 4647 "Matching of Language
	* Tags"</a> and <a href="http://tools.ietf.org/html/rfc5646">RFC 5646 "Tags
	* for Identifying Languages"</a> with support for the LDML (UTS#35, "Unicode
	* Locale Data Markup Language") BCP 47-compatible extensions for locale data
	* exchange.
	*
	* <p> A {@code Locale} object logically consists of the fields
	* described below.
	*
	* <dl>
	* <dt><a id="def_language"><b>language</b></a></dt>
	*
	* <dd>ISO 639 alpha-2 or alpha-3 language code, or registered
	* language subtags up to 8 alpha letters (for future enhancements).
	* When a language has both an alpha-2 code and an alpha-3 code, the
	* alpha-2 code must be used. You can find a full list of valid
	* language codes in the IANA Language Subtag Registry (search for
	* "Type: language"). The language field is case insensitive, but
	* {@code Locale} always canonicalizes to lower case.</dd>
	*
	* <dd>Well-formed language values have the form
	* <code>[a-zA-Z]{2,8}</code>. Note that this is not the full
	* BCP47 language production, since it excludes extlang. They are
	* not needed since modern three-letter language codes replace
	* them.</dd>
	*
	* <dd>Example: "en" (English), "ja" (Japanese), "kok" (Konkani)</dd>
	*
	* <dt><a id="def_script"><b>script</b></a></dt>
	*
	* <dd>ISO 15924 alpha-4 script code. You can find a full list of
	* valid script codes in the IANA Language Subtag Registry (search
	* for "Type: script"). The script field is case insensitive, but
	* {@code Locale} always canonicalizes to title case (the first
	* letter is upper case and the rest of the letters are lower
	* case).</dd>
	*
	* <dd>Well-formed script values have the form
	* <code>[a-zA-Z]{4}</code></dd>
	*
	* <dd>Example: "Latn" (Latin), "Cyrl" (Cyrillic)</dd>
	*
	* <dt><a id="def_region"><b>country (region)</b></a></dt>
	*
	* <dd>ISO 3166 alpha-2 country code or UN M.49 numeric-3 area code.
	* You can find a full list of valid country and region codes in the
	* IANA Language Subtag Registry (search for "Type: region"). The
	* country (region) field is case insensitive, but
	* {@code Locale} always canonicalizes to upper case.</dd>
	*
	* <dd>Well-formed country/region values have
	* the form <code>[a-zA-Z]{2} \| [0-9]{3}</code></dd>
	*
	* <dd>Example: "US" (United States), "FR" (France), "029"
	* (Caribbean)</dd>
	*
	* <dt><a id="def_variant"><b>variant</b></a></dt>
	*
	* <dd>Any arbitrary value used to indicate a variation of a
	* {@code Locale}. Where there are two or more variant values
	* each indicating its own semantics, these values should be ordered
	* by importance, with most important first, separated by
	* underscore('_'). The variant field is case sensitive.</dd>
	*
	* <dd>Note: IETF BCP 47 places syntactic restrictions on variant
	* subtags. Also BCP 47 subtags are strictly used to indicate
	* additional variations that define a language or its dialects that
	* are not covered by any combinations of language, script and
	* region subtags. You can find a full list of valid variant codes
	* in the IANA Language Subtag Registry (search for "Type: variant").
	*
	* <p>However, the variant field in {@code Locale} has
	* historically been used for any kind of variation, not just
	* language variations. For example, some supported variants
	* available in Java SE Runtime Environments indicate alternative
	* cultural behaviors such as calendar type or number script. In
	* BCP 47 this kind of information, which does not identify the
	* language, is supported by extension subtags or private use
	* subtags.</dd>
	*
	* <dd>Well-formed variant values have the form <code>SUBTAG
	* (('_'\|'-') SUBTAG)*</code> where <code>SUBTAG =
	* [0-9][0-9a-zA-Z]{3} \| [0-9a-zA-Z]{5,8}</code>. (Note: BCP 47 only
	* uses hyphen ('-') as a delimiter, this is more lenient).</dd>
	*
	* <dd>Example: "polyton" (Polytonic Greek), "POSIX"</dd>
	*
	* <dt><a id="def_extensions"><b>extensions</b></a></dt>
	*
	* <dd>A map from single character keys to string values, indicating
	* extensions apart from language identification. The extensions in
	* {@code Locale} implement the semantics and syntax of BCP 47
	* extension subtags and private use subtags. The extensions are
	* case insensitive, but {@code Locale} canonicalizes all
	* extension keys and values to lower case. Note that extensions
	* cannot have empty values.</dd>
	*
	* <dd>Well-formed keys are single characters from the set
	* {@code [0-9a-zA-Z]}. Well-formed values have the form
	* {@code SUBTAG ('-' SUBTAG)*} where for the key 'x'
	* <code>SUBTAG = [0-9a-zA-Z]{1,8}</code> and for other keys
	* <code>SUBTAG = [0-9a-zA-Z]{2,8}</code> (that is, 'x' allows
	* single-character subtags).</dd>
	*
	* <dd>Example: key="u"/value="ca-japanese" (Japanese Calendar),
	* key="x"/value="java-1-7"</dd>
	* </dl>
	*
	* <b>Note:</b> Although BCP 47 requires field values to be registered
	* in the IANA Language Subtag Registry, the {@code Locale} class
	* does not provide any validation features. The {@code Builder}
	* only checks if an individual field satisfies the syntactic
	* requirement (is well-formed), but does not validate the value
	* itself. See {@link Builder} for details.
	*
	* <h2><a id="def_locale_extension">Unicode locale/language extension</a></h2>
	*
	* <p>UTS#35, "Unicode Locale Data Markup Language" defines optional
	* attributes and keywords to override or refine the default behavior
	* associated with a locale. A keyword is represented by a pair of
	* key and type. For example, "nu-thai" indicates that Thai local
	* digits (value:"thai") should be used for formatting numbers
	* (key:"nu").
	*
	* <p>The keywords are mapped to a BCP 47 extension value using the
	* extension key 'u' ({@link #UNICODE_LOCALE_EXTENSION}). The above
	* example, "nu-thai", becomes the extension "u-nu-thai".
	*
	* <p>Thus, when a {@code Locale} object contains Unicode locale
	* attributes and keywords,
	* {@code getExtension(UNICODE_LOCALE_EXTENSION)} will return a
	* String representing this information, for example, "nu-thai". The
	* {@code Locale} class also provides {@link
	* #getUnicodeLocaleAttributes}, {@link #getUnicodeLocaleKeys}, and
	* {@link #getUnicodeLocaleType} which allow you to access Unicode
	* locale attributes and key/type pairs directly. When represented as
	* a string, the Unicode Locale Extension lists attributes
	* alphabetically, followed by key/type sequences with keys listed
	* alphabetically (the order of subtags comprising a key's type is
	* fixed when the type is defined)
	*
	* <p>A well-formed locale key has the form
	* <code>[0-9a-zA-Z]{2}</code>. A well-formed locale type has the
	* form <code>"" \| [0-9a-zA-Z]{3,8} ('-' [0-9a-zA-Z]{3,8})*</code> (it
	* can be empty, or a series of subtags 3-8 alphanums in length). A
	* well-formed locale attribute has the form
	* <code>[0-9a-zA-Z]{3,8}</code> (it is a single subtag with the same
	* form as a locale type subtag).
	*
	* <p>The Unicode locale extension specifies optional behavior in
	* locale-sensitive services. Although the LDML specification defines
	* various keys and values, actual locale-sensitive service
	* implementations in a Java Runtime Environment might not support any
	* particular Unicode locale attributes or key/type pairs.
	*
	* <h3>Creating a Locale</h3>
	*
	* <p>There are several different ways to create a {@code Locale}
	* object.
	*
	* <h4>Builder</h4>
	*
	* <p>Using {@link Builder} you can construct a {@code Locale} object
	* that conforms to BCP 47 syntax.
	*
	* <h4>Constructors</h4>
	*
	* <p>The {@code Locale} class provides three constructors:
	* <blockquote>
	* <pre>
	* {@link #Locale(String language)}
	* {@link #Locale(String language, String country)}
	* {@link #Locale(String language, String country, String variant)}
	* </pre>
	* </blockquote>
	* These constructors allow you to create a {@code Locale} object
	* with language, country and variant, but you cannot specify
	* script or extensions.
	*
	* <h4>Factory Methods</h4>
	*
	* <p>The method {@link #forLanguageTag} creates a {@code Locale}
	* object for a well-formed BCP 47 language tag.
	*
	* <h4>Locale Constants</h4>
	*
	* <p>The {@code Locale} class provides a number of convenient constants
	* that you can use to create {@code Locale} objects for commonly used
	* locales. For example, the following creates a {@code Locale} object
	* for the United States:
	* <blockquote>
	* <pre>
	* Locale.US
	* </pre>
	* </blockquote>
	*
	* <h3><a id="LocaleMatching">Locale Matching</a></h3>
	*
	* <p>If an application or a system is internationalized and provides localized
	* resources for multiple locales, it sometimes needs to find one or more
	* locales (or language tags) which meet each user's specific preferences. Note
	* that a term "language tag" is used interchangeably with "locale" in this
	* locale matching documentation.
	*
	* <p>In order to do matching a user's preferred locales to a set of language
	* tags, <a href="http://tools.ietf.org/html/rfc4647">RFC 4647 Matching of
	* Language Tags</a> defines two mechanisms: filtering and lookup.
	* <em>Filtering</em> is used to get all matching locales, whereas
	* <em>lookup</em> is to choose the best matching locale.
	* Matching is done case-insensitively. These matching mechanisms are described
	* in the following sections.
	*
	* <p>A user's preference is called a <em>Language Priority List</em> and is
	* expressed as a list of language ranges. There are syntactically two types of
	* language ranges: basic and extended. See
	* {@link Locale.LanguageRange Locale.LanguageRange} for details.
	*
	* <h4>Filtering</h4>
	*
	* <p>The filtering operation returns all matching language tags. It is defined
	* in RFC 4647 as follows:
	* "In filtering, each language range represents the least specific language
	* tag (that is, the language tag with fewest number of subtags) that is an
	* acceptable match. All of the language tags in the matching set of tags will
	* have an equal or greater number of subtags than the language range. Every
	* non-wildcard subtag in the language range will appear in every one of the
	* matching language tags."
	*
	* <p>There are two types of filtering: filtering for basic language ranges
	* (called "basic filtering") and filtering for extended language ranges
	* (called "extended filtering"). They may return different results by what
	* kind of language ranges are included in the given Language Priority List.
	* {@link Locale.FilteringMode} is a parameter to specify how filtering should
	* be done.
	*
	* <h4>Lookup</h4>
	*
	* <p>The lookup operation returns the best matching language tags. It is
	* defined in RFC 4647 as follows:
	* "By contrast with filtering, each language range represents the most
	* specific tag that is an acceptable match. The first matching tag found,
	* according to the user's priority, is considered the closest match and is the
	* item returned."
	*
	* <p>For example, if a Language Priority List consists of two language ranges,
	* {@code "zh-Hant-TW"} and {@code "en-US"}, in prioritized order, lookup
	* method progressively searches the language tags below in order to find the
	* best matching language tag.
	* <blockquote>
	* <pre>
	* 1. zh-Hant-TW
	* 2. zh-Hant
	* 3. zh
	* 4. en-US
	* 5. en
	* </pre>
	* </blockquote>
	* If there is a language tag which matches completely to a language range
	* above, the language tag is returned.
	*
	* <p>{@code "*"} is the special language range, and it is ignored in lookup.
	*
	* <p>If multiple language tags match as a result of the subtag {@code '*'}
	* included in a language range, the first matching language tag returned by
	* an {@link Iterator} over a {@link Collection} of language tags is treated as
	* the best matching one.
	*
	* <h3>Use of Locale</h3>
	*
	* <p>Once you've created a {@code Locale} you can query it for information
	* about itself. Use {@code getCountry} to get the country (or region)
	* code and {@code getLanguage} to get the language code.
	* You can use {@code getDisplayCountry} to get the
	* name of the country suitable for displaying to the user. Similarly,
	* you can use {@code getDisplayLanguage} to get the name of
	* the language suitable for displaying to the user. Interestingly,
	* the {@code getDisplayXXX} methods are themselves locale-sensitive
	* and have two versions: one that uses the default
	* {@link Locale.Category#DISPLAY DISPLAY} locale and one
	* that uses the locale specified as an argument.
	*
	* <p>The Java Platform provides a number of classes that perform locale-sensitive
	* operations. For example, the {@code NumberFormat} class formats
	* numbers, currency, and percentages in a locale-sensitive manner. Classes
	* such as {@code NumberFormat} have several convenience methods
	* for creating a default object of that type. For example, the
	* {@code NumberFormat} class provides these three convenience methods
	* for creating a default {@code NumberFormat} object:
	* <blockquote>
	* <pre>
	* NumberFormat.getInstance()
	* NumberFormat.getCurrencyInstance()
	* NumberFormat.getPercentInstance()
	* </pre>
	* </blockquote>
	* Each of these methods has two variants; one with an explicit locale
	* and one without; the latter uses the default
	* {@link Locale.Category#FORMAT FORMAT} locale:
	* <blockquote>
	* <pre>
	* NumberFormat.getInstance(myLocale)
	* NumberFormat.getCurrencyInstance(myLocale)
	* NumberFormat.getPercentInstance(myLocale)
	* </pre>
	* </blockquote>
	* A {@code Locale} is the mechanism for identifying the kind of object
	* ({@code NumberFormat}) that you would like to get. The locale is
	* <STRONG>just</STRONG> a mechanism for identifying objects,
	* <STRONG>not</STRONG> a container for the objects themselves.
	*
	* <h3>Compatibility</h3>
	*
	* <p>In order to maintain compatibility with existing usage, Locale's
	* constructors retain their behavior prior to the Java Runtime
	* Environment version 1.7. The same is largely true for the
	* {@code toString} method. Thus Locale objects can continue to
	* be used as they were. In particular, clients who parse the output
	* of toString into language, country, and variant fields can continue
	* to do so (although this is strongly discouraged), although the
	* variant field will have additional information in it if script or
	* extensions are present.
	*
	* <p>In addition, BCP 47 imposes syntax restrictions that are not
	* imposed by Locale's constructors. This means that conversions
	* between some Locales and BCP 47 language tags cannot be made without
	* losing information. Thus {@code toLanguageTag} cannot
	* represent the state of locales whose language, country, or variant
	* do not conform to BCP 47.
	*
	* <p>Because of these issues, it is recommended that clients migrate
	* away from constructing non-conforming locales and use the
	* {@code forLanguageTag} and {@code Locale.Builder} APIs instead.
	* Clients desiring a string representation of the complete locale can
	* then always rely on {@code toLanguageTag} for this purpose.
	*
	* <h4><a id="special_cases_constructor">Special cases</a></h4>
	*
	* <p>For compatibility reasons, two
	* non-conforming locales are treated as special cases. These are
	* <b>{@code ja_JP_JP}</b> and <b>{@code th_TH_TH}</b>. These are ill-formed
	* in BCP 47 since the variants are too short. To ease migration to BCP 47,
	* these are treated specially during construction. These two cases (and only
	* these) cause a constructor to generate an extension, all other values behave
	* exactly as they did prior to Java 7.
	*
	* <p>Java has used {@code ja_JP_JP} to represent Japanese as used in
	* Japan together with the Japanese Imperial calendar. This is now
	* representable using a Unicode locale extension, by specifying the
	* Unicode locale key {@code ca} (for "calendar") and type
	* {@code japanese}. When the Locale constructor is called with the
	* arguments "ja", "JP", "JP", the extension "u-ca-japanese" is
	* automatically added.
	*
	* <p>Java has used {@code th_TH_TH} to represent Thai as used in
	* Thailand together with Thai digits. This is also now representable using
	* a Unicode locale extension, by specifying the Unicode locale key
	* {@code nu} (for "number") and value {@code thai}. When the Locale
	* constructor is called with the arguments "th", "TH", "TH", the
	* extension "u-nu-thai" is automatically added.
	*
	* <h4>Serialization</h4>
	*
	* <p>During serialization, writeObject writes all fields to the output
	* stream, including extensions.
	*
	* <p>During deserialization, readResolve adds extensions as described
	* in <a href="#special_cases_constructor">Special Cases</a>, only
	* for the two cases th_TH_TH and ja_JP_JP.
	*
	* <h4><a id="legacy_language_codes">Legacy language codes</a></h4>
	*
	* <p>Locale's constructor has always converted three language codes to
	* their earlier, obsoleted forms: {@code he} maps to {@code iw},
	* {@code yi} maps to {@code ji}, and {@code id} maps to
	* {@code in}. Since Java SE 17, this is no longer the case. Each
	* language maps to its new form; {@code iw} maps to {@code he}, {@code ji}
	* maps to {@code yi}, and {@code in} maps to {@code id}.
	*
	* <p>For the backward compatible behavior, the system property
	* {@systemProperty java.locale.useOldISOCodes} reverts the behavior
	* back to that of before Java SE 17. If the system property is set to
	* {@code true}, those three current language codes are mapped to their
	* backward compatible forms. The property is only read at Java runtime
	* startup and subsequent calls to {@code System.setProperty()} will
	* have no effect.
	*
	* <p>The APIs added in 1.7 map between the old and new language codes,
	* maintaining the mapped codes internal to Locale (so that
	* {@code getLanguage} and {@code toString} reflect the mapped
	* code, which depends on the {@code java.locale.useOldISOCodes} system
	* property), but using the new codes in the BCP 47 language tag APIs (so
	* that {@code toLanguageTag} reflects the new one). This
	* preserves the equivalence between Locales no matter which code or
	* API is used to construct them. Java's default resource bundle
	* lookup mechanism also implements this mapping, so that resources
	* can be named using either convention, see {@link ResourceBundle.Control}.
	*
	* <h4>Three-letter language/country(region) codes</h4>
	*
	* <p>The Locale constructors have always specified that the language
	* and the country param be two characters in length, although in
	* practice they have accepted any length. The specification has now
	* been relaxed to allow language codes of two to eight characters and
	* country (region) codes of two to three characters, and in
	* particular, three-letter language codes and three-digit region
	* codes as specified in the IANA Language Subtag Registry. For
	* compatibility, the implementation still does not impose a length
	* constraint.
	*
	* @see Builder
	* @see ResourceBundle
	* @see java.text.Format
	* @see java.text.NumberFormat
	* @see java.text.Collator
	* @author Mark Davis
	* @since 1.1
	*/
	public final class Locale implements Cloneable, Serializable {

	/** Useful constant for language.
	*/
	public static final Locale ENGLISH;

	/** Useful constant for language.
	*/
	public static final Locale FRENCH;

	/** Useful constant for language.
	*/
	public static final Locale GERMAN;

	/** Useful constant for language.
	*/
	public static final Locale ITALIAN;

	/** Useful constant for language.
	*/
	public static final Locale JAPANESE;

	/** Useful constant for language.
	*/
	public static final Locale KOREAN;

	/** Useful constant for language.
	*/
	public static final Locale CHINESE;

	/** Useful constant for language.
	*/
	public static final Locale SIMPLIFIED_CHINESE;

	/** Useful constant for language.
	*/
	public static final Locale TRADITIONAL_CHINESE;

	/** Useful constant for country.
	*/
	public static final Locale FRANCE;

	/** Useful constant for country.
	*/
	public static final Locale GERMANY;

	/** Useful constant for country.
	*/
	public static final Locale ITALY;

	/** Useful constant for country.
	*/
	public static final Locale JAPAN;

	/** Useful constant for country.
	*/
	public static final Locale KOREA;

	/** Useful constant for country.
	*/
	public static final Locale UK;

	/** Useful constant for country.
	*/
	public static final Locale US;

	/** Useful constant for country.
	*/
	public static final Locale CANADA;

	/** Useful constant for country.
	*/
	public static final Locale CANADA_FRENCH;

	/**
	* Useful constant for the root locale. The root locale is the locale whose
	* language, country, and variant are empty ("") strings. This is regarded
	* as the base locale of all locales, and is used as the language/country
	* neutral locale for the locale sensitive operations.
	*
	* @since 1.6
	*/
	public static final Locale ROOT;

	private static final Map<BaseLocale, Locale> CONSTANT_LOCALES = new HashMap<>();

	static {
	ENGLISH = createConstant(BaseLocale.ENGLISH);
	FRENCH = createConstant(BaseLocale.FRENCH);
	GERMAN = createConstant(BaseLocale.GERMAN);
	ITALIAN = createConstant(BaseLocale.ITALIAN);
	JAPANESE = createConstant(BaseLocale.JAPANESE);
	KOREAN = createConstant(BaseLocale.KOREAN);
	CHINESE = createConstant(BaseLocale.CHINESE);
	SIMPLIFIED_CHINESE = createConstant(BaseLocale.SIMPLIFIED_CHINESE);
	TRADITIONAL_CHINESE = createConstant(BaseLocale.TRADITIONAL_CHINESE);
	FRANCE = createConstant(BaseLocale.FRANCE);
	GERMANY = createConstant(BaseLocale.GERMANY);
	ITALY = createConstant(BaseLocale.ITALY);
	JAPAN = createConstant(BaseLocale.JAPAN);
	KOREA = createConstant(BaseLocale.KOREA);
	UK = createConstant(BaseLocale.UK);
	US = createConstant(BaseLocale.US);
	CANADA = createConstant(BaseLocale.CANADA);
	CANADA_FRENCH = createConstant(BaseLocale.CANADA_FRENCH);
	ROOT = createConstant(BaseLocale.ROOT);
	}

	/** Useful constant for country.
	*/
	public static final Locale CHINA = SIMPLIFIED_CHINESE;

	/** Useful constant for country.
	*/
	public static final Locale PRC = SIMPLIFIED_CHINESE;

	/** Useful constant for country.
	*/
	public static final Locale TAIWAN = TRADITIONAL_CHINESE;

	/**
	* This method must be called only for creating the Locale.*
	* constants due to making shortcuts.
	*/
	private static Locale createConstant(byte baseType) {
	BaseLocale base = BaseLocale.constantBaseLocales[baseType];
	Locale locale = new Locale(base, null);
	CONSTANT_LOCALES.put(base, locale);
	return locale;
	}

	/**
	* The key for the private use extension ('x').
	*
	* @see #getExtension(char)
	* @see Builder#setExtension(char, String)
	* @since 1.7
	*/
	public static final char PRIVATE_USE_EXTENSION = 'x';

	/**
	* The key for Unicode locale extension ('u').
	*
	* @see #getExtension(char)
	* @see Builder#setExtension(char, String)
	* @since 1.7
	*/
	public static final char UNICODE_LOCALE_EXTENSION = 'u';

	/** serialization ID
	*/
	@java.io.Serial
	static final long serialVersionUID = 9149081749638150636L;

	/**
	* Enum for specifying the type defined in ISO 3166. This enum is used to
	* retrieve the two-letter ISO3166-1 alpha-2, three-letter ISO3166-1
	* alpha-3, four-letter ISO3166-3 country codes.
	*
	* @see #getISOCountries(Locale.IsoCountryCode)
	* @since 9
	*/
	public static enum IsoCountryCode {
	/**
	* PART1_ALPHA2 is used to represent the ISO3166-1 alpha-2 two letter
	* country codes.
	*/
	PART1_ALPHA2 {
	@Override
	Set<String> createCountryCodeSet() {
	return Set.of(Locale.getISOCountries());
	}
	},

	/**
	*
	* PART1_ALPHA3 is used to represent the ISO3166-1 alpha-3 three letter
	* country codes.
	*/
	PART1_ALPHA3 {
	@Override
	Set<String> createCountryCodeSet() {
	return LocaleISOData.computeISO3166_1Alpha3Countries();
	}
	},

	/**
	* PART3 is used to represent the ISO3166-3 four letter country codes.
	*/
	PART3 {
	@Override
	Set<String> createCountryCodeSet() {
	return Set.of(LocaleISOData.ISO3166_3);
	}
	};

	/**
	* Concrete implementation of this method attempts to compute value
	* for iso3166CodesMap for each IsoCountryCode type key.
	*/
	abstract Set<String> createCountryCodeSet();

	/**
	* Map to hold country codes for each ISO3166 part.
	*/
	private static Map<IsoCountryCode, Set<String>> iso3166CodesMap = new ConcurrentHashMap<>();

	/**
	* This method is called from Locale class to retrieve country code set
	* for getISOCountries(type)
	*/
	static Set<String> retrieveISOCountryCodes(IsoCountryCode type) {
	return iso3166CodesMap.computeIfAbsent(type, IsoCountryCode::createCountryCodeSet);
	}
	}

	/**
	* Display types for retrieving localized names from the name providers.
	*/
	private static final int DISPLAY_LANGUAGE = 0;
	private static final int DISPLAY_COUNTRY = 1;
	private static final int DISPLAY_VARIANT = 2;
	private static final int DISPLAY_SCRIPT = 3;
	private static final int DISPLAY_UEXT_KEY = 4;
	private static final int DISPLAY_UEXT_TYPE = 5;

	/**
	* Private constructor used by getInstance method
	*/
	private Locale(BaseLocale baseLocale, LocaleExtensions extensions) {
	this.baseLocale = baseLocale;
	this.localeExtensions = extensions;
	}

	/**
	* Construct a locale from language, country and variant.
	* This constructor normalizes the language value to lowercase and
	* the country value to uppercase.
	* @implNote
	* <ul>
	* <li>Obsolete ISO 639 codes ("iw", "ji", and "in") are mapped to
	* their current forms. See <a href="#legacy_language_codes">Legacy language
	* codes</a> for more information.
	* <li>For backward compatibility reasons, this constructor does not make
	* any syntactic checks on the input.
	* <li>The two cases ("ja", "JP", "JP") and ("th", "TH", "TH") are handled specially,
	* see <a href="#special_cases_constructor">Special Cases</a> for more information.
	* </ul>
	*
	* @param language An ISO 639 alpha-2 or alpha-3 language code, or a language subtag
	* up to 8 characters in length. See the {@code Locale} class description about
	* valid language values.
	* @param country An ISO 3166 alpha-2 country code or a UN M.49 numeric-3 area code.
	* See the {@code Locale} class description about valid country values.
	* @param variant Any arbitrary value used to indicate a variation of a {@code Locale}.
	* See the {@code Locale} class description for the details.
	* @throws NullPointerException thrown if any argument is null.
	*/
	public Locale(String language, String country, String variant) {
	if (language == null \|\| country == null \|\| variant == null) {
	throw new NullPointerException();
	}
	baseLocale = BaseLocale.getInstance(convertOldISOCodes(language), "", country, variant);
	localeExtensions = getCompatibilityExtensions(language, "", country, variant);
	}

	/**
	* Construct a locale from language and country.
	* This constructor normalizes the language value to lowercase and
	* the country value to uppercase.
	* @implNote
	* <ul>
	* <li>Obsolete ISO 639 codes ("iw", "ji", and "in") are mapped to
	* their current forms. See <a href="#legacy_language_codes">Legacy language
	* codes</a> for more information.
	* <li>For backward compatibility reasons, this constructor does not make
	* any syntactic checks on the input.
	* </ul>
	*
	* @param language An ISO 639 alpha-2 or alpha-3 language code, or a language subtag
	* up to 8 characters in length. See the {@code Locale} class description about
	* valid language values.
	* @param country An ISO 3166 alpha-2 country code or a UN M.49 numeric-3 area code.
	* See the {@code Locale} class description about valid country values.
	* @throws NullPointerException thrown if either argument is null.
	*/
	public Locale(String language, String country) {
	this(language, country, "");
	}

	/**
	* Construct a locale from a language code.
	* This constructor normalizes the language value to lowercase.
	* @implNote
	* <ul>
	* <li>Obsolete ISO 639 codes ("iw", "ji", and "in") are mapped to
	* their current forms. See <a href="#legacy_language_codes">Legacy language
	* codes</a> for more information.
	* <li>For backward compatibility reasons, this constructor does not make
	* any syntactic checks on the input.
	* </ul>
	*
	* @param language An ISO 639 alpha-2 or alpha-3 language code, or a language subtag
	* up to 8 characters in length. See the {@code Locale} class description about
	* valid language values.
	* @throws NullPointerException thrown if argument is null.
	* @since 1.4
	*/
	public Locale(String language) {
	this(language, "", "");
	}

	/**
	* Returns a {@code Locale} constructed from the given
	* {@code language}, {@code country} and
	* {@code variant}. If the same {@code Locale} instance
	* is available in the cache, then that instance is
	* returned. Otherwise, a new {@code Locale} instance is
	* created and cached.
	*
	* @param language lowercase 2 to 8 language code.
	* @param country uppercase two-letter ISO-3166 code and numeric-3 UN M.49 area code.
	* @param variant vendor and browser specific code. See class description.
	* @return the {@code Locale} instance requested
	* @throws NullPointerException if any argument is null.
	*/
	static Locale getInstance(String language, String country, String variant) {
	return getInstance(language, "", country, variant, null);
	}

	static Locale getInstance(String language, String script, String country,
	String variant, LocaleExtensions extensions) {
	if (language== null \|\| script == null \|\| country == null \|\| variant == null) {
	throw new NullPointerException();
	}

	if (extensions == null) {
	extensions = getCompatibilityExtensions(language, script, country, variant);
	}

	BaseLocale baseloc = BaseLocale.getInstance(convertOldISOCodes(language), script, country, variant);
	return getInstance(baseloc, extensions);
	}

	static Locale getInstance(BaseLocale baseloc, LocaleExtensions extensions) {
	if (extensions == null) {
	Locale locale = CONSTANT_LOCALES.get(baseloc);
	if (locale != null) {
	return locale;
	}
	return Cache.LOCALECACHE.get(baseloc);
	} else {
	LocaleKey key = new LocaleKey(baseloc, extensions);
	return Cache.LOCALECACHE.get(key);
	}
	}

	private static class Cache extends LocaleObjectCache<Object, Locale> {

	private static final Cache LOCALECACHE = new Cache();

	private Cache() {
	}

	@Override
	protected Locale createObject(Object key) {
	if (key instanceof BaseLocale) {
	return new Locale((BaseLocale)key, null);
	} else {
	LocaleKey lk = (LocaleKey)key;
	return new Locale(lk.base, lk.exts);
	}
	}
	}

	private static final class LocaleKey {
	private final BaseLocale base;
	private final LocaleExtensions exts;
	private final int hash;

	private LocaleKey(BaseLocale baseLocale, LocaleExtensions extensions) {
	base = baseLocale;
	exts = extensions;

	// Calculate the hash value here because it's always used.
	int h = base.hashCode();
	if (exts != null) {
	h ^= exts.hashCode();
	}
	hash = h;
	}

	@Override
	public boolean equals(Object obj) {
	if (this == obj) {
	return true;
	}
	if (!(obj instanceof LocaleKey other)) {
	return false;
	}
	if (hash != other.hash \|\| !base.equals(other.base)) {
	return false;
	}
	if (exts == null) {
	return other.exts == null;
	}
	return exts.equals(other.exts);
	}

	@Override
	public int hashCode() {
	return hash;
	}
	}

	/**
	* Gets the current value of the default locale for this instance
	* of the Java Virtual Machine.
	* <p>
	* The Java Virtual Machine sets the default locale during startup
	* based on the host environment. It is used by many locale-sensitive
	* methods if no locale is explicitly specified.
	* It can be changed using the
	* {@link #setDefault(java.util.Locale) setDefault} method.
	*
	* @return the default locale for this instance of the Java Virtual Machine
	*/
	public static Locale getDefault() {
	// do not synchronize this method - see 4071298
	return defaultLocale;
	}

	/**
	* Gets the current value of the default locale for the specified Category
	* for this instance of the Java Virtual Machine.
	* <p>
	* The Java Virtual Machine sets the default locale during startup based
	* on the host environment. It is used by many locale-sensitive methods
	* if no locale is explicitly specified. It can be changed using the
	* setDefault(Locale.Category, Locale) method.
	*
	* @param category the specified category to get the default locale
	* @throws NullPointerException if category is null
	* @return the default locale for the specified Category for this instance
	* of the Java Virtual Machine
	* @see #setDefault(Locale.Category, Locale)
	* @since 1.7
	*/
	public static Locale getDefault(Locale.Category category) {
	// do not synchronize this method - see 4071298
	Objects.requireNonNull(category);
	if (category == Category.DISPLAY) {
	Locale loc = defaultDisplayLocale; // volatile read
	if (loc == null) {
	loc = getDisplayLocale();
	}
	return loc;
	} else {
	assert category == Category.FORMAT : "Unknown category";
	Locale loc = defaultFormatLocale; // volatile read
	if (loc == null) {
	loc = getFormatLocale();
	}
	return loc;
	}
	}

	private static synchronized Locale getDisplayLocale() {
	Locale loc = defaultDisplayLocale;
	if (loc == null) {
	loc = defaultDisplayLocale = initDefault(Category.DISPLAY);
	}
	return loc;
	}


	private static synchronized Locale getFormatLocale() {
	Locale loc = defaultFormatLocale;
	if (loc == null) {
	loc = defaultFormatLocale = initDefault(Category.FORMAT);
	}
	return loc;
	}

	private static Locale initDefault() {
	String language, region, script, country, variant;
	Properties props = GetPropertyAction.privilegedGetProperties();
	language = props.getProperty("user.language", "en");
	// for compatibility, check for old user.region property
	region = props.getProperty("user.region");
	if (region != null) {
	// region can be of form country, country_variant, or _variant
	int i = region.indexOf('_');
	if (i >= 0) {
	country = region.substring(0, i);
	variant = region.substring(i + 1);
	} else {
	country = region;
	variant = "";
	}
	script = "";
	} else {
	script = props.getProperty("user.script", "");
	country = props.getProperty("user.country", "");
	variant = props.getProperty("user.variant", "");
	}

	return getInstance(language, script, country, variant,
	getDefaultExtensions(props.getProperty("user.extensions", ""))
	.orElse(null));
	}

	private static Locale initDefault(Locale.Category category) {
	Properties props = GetPropertyAction.privilegedGetProperties();

	return getInstance(
	props.getProperty(category.languageKey,
	defaultLocale.getLanguage()),
	props.getProperty(category.scriptKey,
	defaultLocale.getScript()),
	props.getProperty(category.countryKey,
	defaultLocale.getCountry()),
	props.getProperty(category.variantKey,
	defaultLocale.getVariant()),
	getDefaultExtensions(props.getProperty(category.extensionsKey, ""))
	.orElse(defaultLocale.getLocaleExtensions()));
	}

	private static Optional<LocaleExtensions> getDefaultExtensions(String extensionsProp) {
	if (LocaleUtils.isEmpty(extensionsProp)) {
	return Optional.empty();
	}

	LocaleExtensions exts = null;
	try {
	exts = new InternalLocaleBuilder()
	.setExtensions(extensionsProp)
	.getLocaleExtensions();
	} catch (LocaleSyntaxException e) {
	// just ignore this incorrect property
	}

	return Optional.ofNullable(exts);
	}

	/**
	* Sets the default locale for this instance of the Java Virtual Machine.
	* This does not affect the host locale.
	* <p>
	* If there is a security manager, its {@code checkPermission}
	* method is called with a {@code PropertyPermission("user.language", "write")}
	* permission before the default locale is changed.
	* <p>
	* The Java Virtual Machine sets the default locale during startup
	* based on the host environment. It is used by many locale-sensitive
	* methods if no locale is explicitly specified.
	* <p>
	* Since changing the default locale may affect many different areas
	* of functionality, this method should only be used if the caller
	* is prepared to reinitialize locale-sensitive code running
	* within the same Java Virtual Machine.
	* <p>
	* By setting the default locale with this method, all of the default
	* locales for each Category are also set to the specified default locale.
	*
	* @throws SecurityException
	* if a security manager exists and its
	* {@code checkPermission} method doesn't allow the operation.
	* @throws NullPointerException if {@code newLocale} is null
	* @param newLocale the new default locale
	* @see SecurityManager#checkPermission
	* @see java.util.PropertyPermission
	*/
	public static synchronized void setDefault(Locale newLocale) {
	setDefault(Category.DISPLAY, newLocale);
	setDefault(Category.FORMAT, newLocale);
	defaultLocale = newLocale;
	}

	/**
	* Sets the default locale for the specified Category for this instance
	* of the Java Virtual Machine. This does not affect the host locale.
	* <p>
	* If there is a security manager, its checkPermission method is called
	* with a PropertyPermission("user.language", "write") permission before
	* the default locale is changed.
	* <p>
	* The Java Virtual Machine sets the default locale during startup based
	* on the host environment. It is used by many locale-sensitive methods
	* if no locale is explicitly specified.
	* <p>
	* Since changing the default locale may affect many different areas of
	* functionality, this method should only be used if the caller is
	* prepared to reinitialize locale-sensitive code running within the
	* same Java Virtual Machine.
	*
	* @param category the specified category to set the default locale
	* @param newLocale the new default locale
	* @throws SecurityException if a security manager exists and its
	* checkPermission method doesn't allow the operation.
	* @throws NullPointerException if category and/or newLocale is null
	* @see SecurityManager#checkPermission(java.security.Permission)
	* @see PropertyPermission
	* @see #getDefault(Locale.Category)
	* @since 1.7
	*/
	public static synchronized void setDefault(Locale.Category category,
	Locale newLocale) {
	if (category == null)
	throw new NullPointerException("Category cannot be NULL");
	if (newLocale == null)
	throw new NullPointerException("Can't set default locale to NULL");

	@SuppressWarnings("removal")
	SecurityManager sm = System.getSecurityManager();
	if (sm != null) sm.checkPermission(new PropertyPermission
	("user.language", "write"));
	switch (category) {
	case DISPLAY:
	defaultDisplayLocale = newLocale;
	break;
	case FORMAT:
	defaultFormatLocale = newLocale;
	break;
	default:
	assert false: "Unknown Category";
	}
	}

	/**
	* Returns an array of all installed locales.
	* The returned array represents the union of locales supported
	* by the Java runtime environment and by installed
	* {@link java.util.spi.LocaleServiceProvider LocaleServiceProvider}
	* implementations. It must contain at least a {@code Locale}
	* instance equal to {@link java.util.Locale#US Locale.US}.
	*
	* @return An array of installed locales.
	*/
	public static Locale[] getAvailableLocales() {
	return LocaleServiceProviderPool.getAllAvailableLocales();
	}

	/**
	* Returns a list of all 2-letter country codes defined in ISO 3166.
	* Can be used to create Locales.
	* This method is equivalent to {@link #getISOCountries(Locale.IsoCountryCode type)}
	* with {@code type} {@link IsoCountryCode#PART1_ALPHA2}.
	* <p>
	* <b>Note:</b> The {@code Locale} class also supports other codes for
	* country (region), such as 3-letter numeric UN M.49 area codes.
	* Therefore, the list returned by this method does not contain ALL valid
	* codes that can be used to create Locales.
	* <p>
	* Note that this method does not return obsolete 2-letter country codes.
	* ISO3166-3 codes which designate country codes for those obsolete codes,
	* can be retrieved from {@link #getISOCountries(Locale.IsoCountryCode type)} with
	* {@code type} {@link IsoCountryCode#PART3}.
	* @return An array of ISO 3166 two-letter country codes.
	*/
	public static String[] getISOCountries() {
	if (isoCountries == null) {
	isoCountries = getISO2Table(LocaleISOData.isoCountryTable);
	}
	String[] result = new String[isoCountries.length];
	System.arraycopy(isoCountries, 0, result, 0, isoCountries.length);
	return result;
	}

	/**
	* Returns a {@code Set} of ISO3166 country codes for the specified type.
	*
	* @param type {@link Locale.IsoCountryCode} specified ISO code type.
	* @see java.util.Locale.IsoCountryCode
	* @throws NullPointerException if type is null
	* @return a {@code Set} of ISO country codes for the specified type.
	* @since 9
	*/
	public static Set<String> getISOCountries(IsoCountryCode type) {
	Objects.requireNonNull(type);
	return IsoCountryCode.retrieveISOCountryCodes(type);
	}

	/**
	* Returns a list of all 2-letter language codes defined in ISO 639.
	* Can be used to create Locales.
	* <p>
	* <b>Note:</b>
	* <ul>
	* <li>ISO 639 is not a stable standard— some languages' codes have changed.
	* The list this function returns includes both the new and the old codes for the
	* languages whose codes have changed.
	* <li>The {@code Locale} class also supports language codes up to
	* 8 characters in length. Therefore, the list returned by this method does
	* not contain ALL valid codes that can be used to create Locales.
	* </ul>
	*
	* @return An array of ISO 639 two-letter language codes.
	*/
	public static String[] getISOLanguages() {
	if (isoLanguages == null) {
	isoLanguages = getISO2Table(LocaleISOData.isoLanguageTable);
	}
	String[] result = new String[isoLanguages.length];
	System.arraycopy(isoLanguages, 0, result, 0, isoLanguages.length);
	return result;
	}

	private static String[] getISO2Table(String table) {
	int len = table.length() / 5;
	String[] isoTable = new String[len];
	for (int i = 0, j = 0; i < len; i++, j += 5) {
	isoTable[i] = table.substring(j, j + 2);
	}
	return isoTable;
	}

	/**
	* Returns the language code of this Locale.
	*
	* @implNote This method returns the new forms for the obsolete ISO 639
	* codes ("iw", "ji", and "in"). See <a href="#legacy_language_codes">
	* Legacy language codes</a> for more information.
	*
	* @return The language code, or the empty string if none is defined.
	* @see #getDisplayLanguage
	*/
	public String getLanguage() {
	return baseLocale.getLanguage();
	}

	/**
	* Returns the script for this locale, which should
	* either be the empty string or an ISO 15924 4-letter script
	* code. The first letter is uppercase and the rest are
	* lowercase, for example, 'Latn', 'Cyrl'.
	*
	* @return The script code, or the empty string if none is defined.
	* @see #getDisplayScript
	* @since 1.7
	*/
	public String getScript() {
	return baseLocale.getScript();
	}

	/**
	* Returns the country/region code for this locale, which should
	* either be the empty string, an uppercase ISO 3166 2-letter code,
	* or a UN M.49 3-digit code.
	*
	* @return The country/region code, or the empty string if none is defined.
	* @see #getDisplayCountry
	*/
	public String getCountry() {
	return baseLocale.getRegion();
	}

	/**
	* Returns the variant code for this locale.
	*
	* @return The variant code, or the empty string if none is defined.
	* @see #getDisplayVariant
	*/
	public String getVariant() {
	return baseLocale.getVariant();
	}

	/**
	* Returns {@code true} if this {@code Locale} has any <a href="#def_extensions">
	* extensions</a>.
	*
	* @return {@code true} if this {@code Locale} has any extensions
	* @since 1.8
	*/
	public boolean hasExtensions() {
	return localeExtensions != null;
	}

	/**
	* Returns a copy of this {@code Locale} with no <a href="#def_extensions">
	* extensions</a>. If this {@code Locale} has no extensions, this {@code Locale}
	* is returned.
	*
	* @return a copy of this {@code Locale} with no extensions, or {@code this}
	* if {@code this} has no extensions
	* @since 1.8
	*/
	public Locale stripExtensions() {
	return hasExtensions() ? Locale.getInstance(baseLocale, null) : this;
	}

	/**
	* Returns the extension (or private use) value associated with
	* the specified key, or null if there is no extension
	* associated with the key. To be well-formed, the key must be one
	* of {@code [0-9A-Za-z]}. Keys are case-insensitive, so
	* for example 'z' and 'Z' represent the same extension.
	*
	* @param key the extension key
	* @return The extension, or null if this locale defines no
	* extension for the specified key.
	* @throws IllegalArgumentException if key is not well-formed
	* @see #PRIVATE_USE_EXTENSION
	* @see #UNICODE_LOCALE_EXTENSION
	* @since 1.7
	*/
	public String getExtension(char key) {
	if (!LocaleExtensions.isValidKey(key)) {
	throw new IllegalArgumentException("Ill-formed extension key: " + key);
	}
	return hasExtensions() ? localeExtensions.getExtensionValue(key) : null;
	}

	/**
	* Returns the set of extension keys associated with this locale, or the
	* empty set if it has no extensions. The returned set is unmodifiable.
	* The keys will all be lower-case.
	*
	* @return The set of extension keys, or the empty set if this locale has
	* no extensions.
	* @since 1.7
	*/
	public Set<Character> getExtensionKeys() {
	if (!hasExtensions()) {
	return Collections.emptySet();
	}
	return localeExtensions.getKeys();
	}

	/**
	* Returns the set of unicode locale attributes associated with
	* this locale, or the empty set if it has no attributes. The
	* returned set is unmodifiable.
	*
	* @return The set of attributes.
	* @since 1.7
	*/
	public Set<String> getUnicodeLocaleAttributes() {
	if (!hasExtensions()) {
	return Collections.emptySet();
	}
	return localeExtensions.getUnicodeLocaleAttributes();
	}

	/**
	* Returns the Unicode locale type associated with the specified Unicode locale key
	* for this locale. Returns the empty string for keys that are defined with no type.
	* Returns null if the key is not defined. Keys are case-insensitive. The key must
	* be two alphanumeric characters ([0-9a-zA-Z]), or an IllegalArgumentException is
	* thrown.
	*
	* @param key the Unicode locale key
	* @return The Unicode locale type associated with the key, or null if the
	* locale does not define the key.
	* @throws IllegalArgumentException if the key is not well-formed
	* @throws NullPointerException if {@code key} is null
	* @since 1.7
	*/
	public String getUnicodeLocaleType(String key) {
	if (!isUnicodeExtensionKey(key)) {
	throw new IllegalArgumentException("Ill-formed Unicode locale key: " + key);
	}
	return hasExtensions() ? localeExtensions.getUnicodeLocaleType(key) : null;
	}

	/**
	* Returns the set of Unicode locale keys defined by this locale, or the empty set if
	* this locale has none. The returned set is immutable. Keys are all lower case.
	*
	* @return The set of Unicode locale keys, or the empty set if this locale has
	* no Unicode locale keywords.
	* @since 1.7
	*/
	public Set<String> getUnicodeLocaleKeys() {
	if (localeExtensions == null) {
	return Collections.emptySet();
	}
	return localeExtensions.getUnicodeLocaleKeys();
	}

	/**
	* Package locale method returning the Locale's BaseLocale,
	* used by ResourceBundle
	* @return base locale of this Locale
	*/
	BaseLocale getBaseLocale() {
	return baseLocale;
	}

	/**
	* Package private method returning the Locale's LocaleExtensions,
	* used by ResourceBundle.
	* @return locale extensions of this Locale,
	* or {@code null} if no extensions are defined
	*/
	LocaleExtensions getLocaleExtensions() {
	return localeExtensions;
	}

	/**
	* Returns a string representation of this {@code Locale}
	* object, consisting of language, country, variant, script,
	* and extensions as below:
	* <blockquote>
	* language + "_" + country + "_" + (variant + "_#" \| "#") + script + "_" + extensions
	* </blockquote>
	*
	* Language is always lower case, country is always upper case, script is always title
	* case, and extensions are always lower case. Extensions and private use subtags
	* will be in canonical order as explained in {@link #toLanguageTag}.
	*
	* <p>When the locale has neither script nor extensions, the result is the same as in
	* Java 6 and prior.
	*
	* <p>If both the language and country fields are missing, this function will return
	* the empty string, even if the variant, script, or extensions field is present (you
	* can't have a locale with just a variant, the variant must accompany a well-formed
	* language or country code).
	*
	* <p>If script or extensions are present and variant is missing, no underscore is
	* added before the "#".
	*
	* <p>This behavior is designed to support debugging and to be compatible with
	* previous uses of {@code toString} that expected language, country, and variant
	* fields only. To represent a Locale as a String for interchange purposes, use
	* {@link #toLanguageTag}.
	*
	* <p>Examples: <ul>
	* <li>{@code en}</li>
	* <li>{@code de_DE}</li>
	* <li>{@code _GB}</li>
	* <li>{@code en_US_WIN}</li>
	* <li>{@code de__POSIX}</li>
	* <li>{@code zh_CN_#Hans}</li>
	* <li>{@code zh_TW_#Hant_x-java}</li>
	* <li>{@code th_TH_TH_#u-nu-thai}</li></ul>
	*
	* @return A string representation of the Locale, for debugging.
	* @see #getDisplayName
	* @see #toLanguageTag
	*/
	@Override
	public final String toString() {
	boolean l = !baseLocale.getLanguage().isEmpty();
	boolean s = !baseLocale.getScript().isEmpty();
	boolean r = !baseLocale.getRegion().isEmpty();
	boolean v = !baseLocale.getVariant().isEmpty();
	boolean e = localeExtensions != null && !localeExtensions.getID().isEmpty();

	StringBuilder result = new StringBuilder(baseLocale.getLanguage());
	if (r \|\| (l && (v \|\| s \|\| e))) {
	result.append('_')
	.append(baseLocale.getRegion()); // This may just append '_'
	}
	if (v && (l \|\| r)) {
	result.append('_')
	.append(baseLocale.getVariant());
	}

	if (s && (l \|\| r)) {
	result.append("_#")
	.append(baseLocale.getScript());
	}

	if (e && (l \|\| r)) {
	result.append('_');
	if (!s) {
	result.append('#');
	}
	result.append(localeExtensions.getID());
	}

	return result.toString();
	}

	/**
	* Returns a well-formed IETF BCP 47 language tag representing
	* this locale.
	*
	* <p>If this {@code Locale} has a language, country, or
	* variant that does not satisfy the IETF BCP 47 language tag
	* syntax requirements, this method handles these fields as
	* described below:
	*
	* <p><b>Language:</b> If language is empty, or not <a
	* href="#def_language" >well-formed</a> (for example "a" or
	* "e2"), it will be emitted as "und" (Undetermined).
	*
	* <p><b>Country:</b> If country is not <a
	* href="#def_region">well-formed</a> (for example "12" or "USA"),
	* it will be omitted.
	*
	* <p><b>Variant:</b> If variant <b>is</b> <a
	* href="#def_variant">well-formed</a>, each sub-segment
	* (delimited by '-' or '_') is emitted as a subtag. Otherwise:
	* <ul>
	*
	* <li>if all sub-segments match <code>[0-9a-zA-Z]{1,8}</code>
	* (for example "WIN" or "Oracle_JDK_Standard_Edition"), the first
	* ill-formed sub-segment and all following will be appended to
	* the private use subtag. The first appended subtag will be
	* "lvariant", followed by the sub-segments in order, separated by
	* hyphen. For example, "x-lvariant-WIN",
	* "Oracle-x-lvariant-JDK-Standard-Edition".
	*
	* <li>if any sub-segment does not match
	* <code>[0-9a-zA-Z]{1,8}</code>, the variant will be truncated
	* and the problematic sub-segment and all following sub-segments
	* will be omitted. If the remainder is non-empty, it will be
	* emitted as a private use subtag as above (even if the remainder
	* turns out to be well-formed). For example,
	* "Solaris_isjustthecoolestthing" is emitted as
	* "x-lvariant-Solaris", not as "solaris".</li></ul>
	*
	* <p><b>Special Conversions:</b> Java supports some old locale
	* representations, including deprecated ISO language codes,
	* for compatibility. This method performs the following
	* conversions:
	* <ul>
	*
	* <li>Deprecated ISO language codes "iw", "ji", and "in" are
	* converted to "he", "yi", and "id", respectively.
	*
	* <li>A locale with language "no", country "NO", and variant
	* "NY", representing Norwegian Nynorsk (Norway), is converted
	* to a language tag "nn-NO".</li></ul>
	*
	* <p><b>Note:</b> Although the language tag created by this
	* method is well-formed (satisfies the syntax requirements
	* defined by the IETF BCP 47 specification), it is not
	* necessarily a valid BCP 47 language tag. For example,
	* <pre>
	* new Locale("xx", "YY").toLanguageTag();</pre>
	*
	* will return "xx-YY", but the language subtag "xx" and the
	* region subtag "YY" are invalid because they are not registered
	* in the IANA Language Subtag Registry.
	*
	* @return a BCP47 language tag representing the locale
	* @see #forLanguageTag(String)
	* @since 1.7
	*/
	public String toLanguageTag() {
	if (languageTag != null) {
	return languageTag;
	}

	LanguageTag tag = LanguageTag.parseLocale(baseLocale, localeExtensions);
	StringBuilder buf = new StringBuilder();

	String subtag = tag.getLanguage();
	if (!subtag.isEmpty()) {
	buf.append(LanguageTag.canonicalizeLanguage(subtag));
	}

	subtag = tag.getScript();
	if (!subtag.isEmpty()) {
	buf.append(LanguageTag.SEP);
	buf.append(LanguageTag.canonicalizeScript(subtag));
	}

	subtag = tag.getRegion();
	if (!subtag.isEmpty()) {
	buf.append(LanguageTag.SEP);
	buf.append(LanguageTag.canonicalizeRegion(subtag));
	}

	List<String>subtags = tag.getVariants();
	for (String s : subtags) {
	buf.append(LanguageTag.SEP);
	// preserve casing
	buf.append(s);
	}

	subtags = tag.getExtensions();
	for (String s : subtags) {
	buf.append(LanguageTag.SEP);
	buf.append(LanguageTag.canonicalizeExtension(s));
	}

	subtag = tag.getPrivateuse();
	if (!subtag.isEmpty()) {
	if (buf.length() > 0) {
	buf.append(LanguageTag.SEP);
	}
	buf.append(LanguageTag.PRIVATEUSE).append(LanguageTag.SEP);
	// preserve casing
	buf.append(subtag);
	}

	String langTag = buf.toString();
	synchronized (this) {
	if (languageTag == null) {
	languageTag = langTag;
	}
	}
	return languageTag;
	}

	/**
	* Returns a locale for the specified IETF BCP 47 language tag string.
	*
	* <p>If the specified language tag contains any ill-formed subtags,
	* the first such subtag and all following subtags are ignored. Compare
	* to {@link Locale.Builder#setLanguageTag} which throws an exception
	* in this case.
	*
	* <p>The following <b>conversions</b> are performed:<ul>
	*
	* <li>The language code "und" is mapped to language "".
	*
	* <li>The language codes "iw", "ji", and "in" are mapped to "he",
	* "yi", and "id" respectively. (This is the same canonicalization
	* that's done in Locale's constructors.) See
	* <a href="#legacy_language_codes">Legacy language codes</a>
	* for more information.
	*
	* <li>The portion of a private use subtag prefixed by "lvariant",
	* if any, is removed and appended to the variant field in the
	* result locale (without case normalization). If it is then
	* empty, the private use subtag is discarded:
	*
	* <pre>
	* Locale loc;
	* loc = Locale.forLanguageTag("en-US-x-lvariant-POSIX");
	* loc.getVariant(); // returns "POSIX"
	* loc.getExtension('x'); // returns null
	*
	* loc = Locale.forLanguageTag("de-POSIX-x-URP-lvariant-Abc-Def");
	* loc.getVariant(); // returns "POSIX_Abc_Def"
	* loc.getExtension('x'); // returns "urp"
	* </pre>
	*
	* <li>When the languageTag argument contains an extlang subtag,
	* the first such subtag is used as the language, and the primary
	* language subtag and other extlang subtags are ignored:
	*
	* <pre>
	* Locale.forLanguageTag("ar-aao").getLanguage(); // returns "aao"
	* Locale.forLanguageTag("en-abc-def-us").toString(); // returns "abc_US"
	* </pre>
	*
	* <li>Case is normalized except for variant tags, which are left
	* unchanged. Language is normalized to lower case, script to
	* title case, country to upper case, and extensions to lower
	* case.
	*
	* <li>If, after processing, the locale would exactly match either
	* ja_JP_JP or th_TH_TH with no extensions, the appropriate
	* extensions are added as though the constructor had been called:
	*
	* <pre>
	* Locale.forLanguageTag("ja-JP-x-lvariant-JP").toLanguageTag();
	* // returns "ja-JP-u-ca-japanese-x-lvariant-JP"
	* Locale.forLanguageTag("th-TH-x-lvariant-TH").toLanguageTag();
	* // returns "th-TH-u-nu-thai-x-lvariant-TH"
	* </pre></ul>
	*
	* <p>This implements the 'Language-Tag' production of BCP47, and
	* so supports legacy (regular and irregular, referred to as
	* "Type: grandfathered" in BCP47) as well as
	* private use language tags. Stand alone private use tags are
	* represented as empty language and extension 'x-whatever',
	* and legacy tags are converted to their canonical replacements
	* where they exist.
	*
	* <p>Legacy tags with canonical replacements are as follows:
	*
	* <table class="striped">
	* <caption style="display:none">Legacy tags with canonical replacements</caption>
	* <thead style="text-align:center">
	* <tr><th scope="col" style="padding: 0 2px">legacy tag</th><th scope="col" style="padding: 0 2px">modern replacement</th></tr>
	* </thead>
	* <tbody style="text-align:center">
	* <tr><th scope="row">art-lojban</th><td>jbo</td></tr>
	* <tr><th scope="row">i-ami</th><td>ami</td></tr>
	* <tr><th scope="row">i-bnn</th><td>bnn</td></tr>
	* <tr><th scope="row">i-hak</th><td>hak</td></tr>
	* <tr><th scope="row">i-klingon</th><td>tlh</td></tr>
	* <tr><th scope="row">i-lux</th><td>lb</td></tr>
	* <tr><th scope="row">i-navajo</th><td>nv</td></tr>
	* <tr><th scope="row">i-pwn</th><td>pwn</td></tr>
	* <tr><th scope="row">i-tao</th><td>tao</td></tr>
	* <tr><th scope="row">i-tay</th><td>tay</td></tr>
	* <tr><th scope="row">i-tsu</th><td>tsu</td></tr>
	* <tr><th scope="row">no-bok</th><td>nb</td></tr>
	* <tr><th scope="row">no-nyn</th><td>nn</td></tr>
	* <tr><th scope="row">sgn-BE-FR</th><td>sfb</td></tr>
	* <tr><th scope="row">sgn-BE-NL</th><td>vgt</td></tr>
	* <tr><th scope="row">sgn-CH-DE</th><td>sgg</td></tr>
	* <tr><th scope="row">zh-guoyu</th><td>cmn</td></tr>
	* <tr><th scope="row">zh-hakka</th><td>hak</td></tr>
	* <tr><th scope="row">zh-min-nan</th><td>nan</td></tr>
	* <tr><th scope="row">zh-xiang</th><td>hsn</td></tr>
	* </tbody>
	* </table>
	*
	* <p>Legacy tags with no modern replacement will be
	* converted as follows:
	*
	* <table class="striped">
	* <caption style="display:none">Legacy tags with no modern replacement</caption>
	* <thead style="text-align:center">
	* <tr><th scope="col" style="padding: 0 2px">legacy tag</th><th scope="col" style="padding: 0 2px">converts to</th></tr>
	* </thead>
	* <tbody style="text-align:center">
	* <tr><th scope="row">cel-gaulish</th><td>xtg-x-cel-gaulish</td></tr>
	* <tr><th scope="row">en-GB-oed</th><td>en-GB-x-oed</td></tr>
	* <tr><th scope="row">i-default</th><td>en-x-i-default</td></tr>
	* <tr><th scope="row">i-enochian</th><td>und-x-i-enochian</td></tr>
	* <tr><th scope="row">i-mingo</th><td>see-x-i-mingo</td></tr>
	* <tr><th scope="row">zh-min</th><td>nan-x-zh-min</td></tr>
	* </tbody>
	* </table>
	*
	* <p>For a list of all legacy tags, see the
	* IANA Language Subtag Registry (search for "Type: grandfathered").
	*
	* <p><b>Note</b>: there is no guarantee that {@code toLanguageTag}
	* and {@code forLanguageTag} will round-trip.
	*
	* @param languageTag the language tag
	* @return The locale that best represents the language tag.
	* @throws NullPointerException if {@code languageTag} is {@code null}
	* @see #toLanguageTag()
	* @see java.util.Locale.Builder#setLanguageTag(String)
	* @since 1.7
	*/
	public static Locale forLanguageTag(String languageTag) {
	LanguageTag tag = LanguageTag.parse(languageTag, null);
	InternalLocaleBuilder bldr = new InternalLocaleBuilder();
	bldr.setLanguageTag(tag);
	BaseLocale base = bldr.getBaseLocale();
	LocaleExtensions exts = bldr.getLocaleExtensions();
	if (exts == null && !base.getVariant().isEmpty()) {
	exts = getCompatibilityExtensions(base.getLanguage(), base.getScript(),
	base.getRegion(), base.getVariant());
	}
	return getInstance(base, exts);
	}

	/**
	* Returns a three-letter abbreviation of this locale's language.
	* If the language matches an ISO 639-1 two-letter code, the
	* corresponding ISO 639-2/T three-letter lowercase code is
	* returned. The ISO 639-2 language codes can be found on-line,
	* see "Codes for the Representation of Names of Languages Part 2:
	* Alpha-3 Code". If the locale specifies a three-letter
	* language, the language is returned as is. If the locale does
	* not specify a language the empty string is returned.
	*
	* @return A three-letter abbreviation of this locale's language.
	* @throws MissingResourceException Throws MissingResourceException if
	* three-letter language abbreviation is not available for this locale.
	*/
	public String getISO3Language() throws MissingResourceException {
	String lang = baseLocale.getLanguage();
	if (lang.length() == 3) {
	return lang;
	}

	String language3 = getISO3Code(lang, LocaleISOData.isoLanguageTable);
	if (language3 == null) {
	throw new MissingResourceException("Couldn't find 3-letter language code for "
	+ lang, "FormatData_" + toString(), "ShortLanguage");
	}
	return language3;
	}

	/**
	* Returns a three-letter abbreviation for this locale's country.
	* If the country matches an ISO 3166-1 alpha-2 code, the
	* corresponding ISO 3166-1 alpha-3 uppercase code is returned.
	* If the locale doesn't specify a country, this will be the empty
	* string.
	*
	* <p>The ISO 3166-1 codes can be found on-line.
	*
	* @return A three-letter abbreviation of this locale's country.
	* @throws MissingResourceException Throws MissingResourceException if the
	* three-letter country abbreviation is not available for this locale.
	*/
	public String getISO3Country() throws MissingResourceException {
	String country3 = getISO3Code(baseLocale.getRegion(), LocaleISOData.isoCountryTable);
	if (country3 == null) {
	throw new MissingResourceException("Couldn't find 3-letter country code for "
	+ baseLocale.getRegion(), "FormatData_" + toString(), "ShortCountry");
	}
	return country3;
	}

	private static String getISO3Code(String iso2Code, String table) {
	int codeLength = iso2Code.length();
	if (codeLength == 0) {
	return "";
	}

	int tableLength = table.length();
	int index = tableLength;
	if (codeLength == 2) {
	char c1 = iso2Code.charAt(0);
	char c2 = iso2Code.charAt(1);
	for (index = 0; index < tableLength; index += 5) {
	if (table.charAt(index) == c1
	&& table.charAt(index + 1) == c2) {
	break;
	}
	}
	}
	return index < tableLength ? table.substring(index + 2, index + 5) : null;
	}

	/**
	* Returns a name for the locale's language that is appropriate for display to the
	* user.
	* If possible, the name returned will be localized for the default
	* {@link Locale.Category#DISPLAY DISPLAY} locale.
	* For example, if the locale is fr_FR and the default
	* {@link Locale.Category#DISPLAY DISPLAY} locale
	* is en_US, getDisplayLanguage() will return "French"; if the locale is en_US and
	* the default {@link Locale.Category#DISPLAY DISPLAY} locale is fr_FR,
	* getDisplayLanguage() will return "anglais".
	* If the name returned cannot be localized for the default
	* {@link Locale.Category#DISPLAY DISPLAY} locale,
	* (say, we don't have a Japanese name for Croatian),
	* this function falls back on the English name, and uses the ISO code as a last-resort
	* value. If the locale doesn't specify a language, this function returns the empty string.
	*
	* @return The name of the display language.
	*/
	public final String getDisplayLanguage() {
	return getDisplayLanguage(getDefault(Category.DISPLAY));
	}

	/**
	* Returns a name for the locale's language that is appropriate for display to the
	* user.
	* If possible, the name returned will be localized according to inLocale.
	* For example, if the locale is fr_FR and inLocale
	* is en_US, getDisplayLanguage() will return "French"; if the locale is en_US and
	* inLocale is fr_FR, getDisplayLanguage() will return "anglais".
	* If the name returned cannot be localized according to inLocale,
	* (say, we don't have a Japanese name for Croatian),
	* this function falls back on the English name, and finally
	* on the ISO code as a last-resort value. If the locale doesn't specify a language,
	* this function returns the empty string.
	*
	* @param inLocale The locale for which to retrieve the display language.
	* @return The name of the display language appropriate to the given locale.
	* @throws NullPointerException if {@code inLocale} is {@code null}
	*/
	public String getDisplayLanguage(Locale inLocale) {
	return getDisplayString(baseLocale.getLanguage(), null, inLocale, DISPLAY_LANGUAGE);
	}

	/**
	* Returns a name for the locale's script that is appropriate for display to
	* the user. If possible, the name will be localized for the default
	* {@link Locale.Category#DISPLAY DISPLAY} locale. Returns
	* the empty string if this locale doesn't specify a script code.
	*
	* @return the display name of the script code for the current default
	* {@link Locale.Category#DISPLAY DISPLAY} locale
	* @since 1.7
	*/
	public String getDisplayScript() {
	return getDisplayScript(getDefault(Category.DISPLAY));
	}

	/**
	* Returns a name for the locale's script that is appropriate
	* for display to the user. If possible, the name will be
	* localized for the given locale. Returns the empty string if
	* this locale doesn't specify a script code.
	*
	* @param inLocale The locale for which to retrieve the display script.
	* @return the display name of the script code for the current default
	* {@link Locale.Category#DISPLAY DISPLAY} locale
	* @throws NullPointerException if {@code inLocale} is {@code null}
	* @since 1.7
	*/
	public String getDisplayScript(Locale inLocale) {
	return getDisplayString(baseLocale.getScript(), null, inLocale, DISPLAY_SCRIPT);
	}

	/**
	* Returns a name for the locale's country that is appropriate for display to the
	* user.
	* If possible, the name returned will be localized for the default
	* {@link Locale.Category#DISPLAY DISPLAY} locale.
	* For example, if the locale is fr_FR and the default
	* {@link Locale.Category#DISPLAY DISPLAY} locale
	* is en_US, getDisplayCountry() will return "France"; if the locale is en_US and
	* the default {@link Locale.Category#DISPLAY DISPLAY} locale is fr_FR,
	* getDisplayCountry() will return "Etats-Unis".
	* If the name returned cannot be localized for the default
	* {@link Locale.Category#DISPLAY DISPLAY} locale,
	* (say, we don't have a Japanese name for Croatia),
	* this function falls back on the English name, and uses the ISO code as a last-resort
	* value. If the locale doesn't specify a country, this function returns the empty string.
	*
	* @return The name of the country appropriate to the locale.
	*/
	public final String getDisplayCountry() {
	return getDisplayCountry(getDefault(Category.DISPLAY));
	}

	/**
	* Returns a name for the locale's country that is appropriate for display to the
	* user.
	* If possible, the name returned will be localized according to inLocale.
	* For example, if the locale is fr_FR and inLocale
	* is en_US, getDisplayCountry() will return "France"; if the locale is en_US and
	* inLocale is fr_FR, getDisplayCountry() will return "Etats-Unis".
	* If the name returned cannot be localized according to inLocale.
	* (say, we don't have a Japanese name for Croatia),
	* this function falls back on the English name, and finally
	* on the ISO code as a last-resort value. If the locale doesn't specify a country,
	* this function returns the empty string.
	*
	* @param inLocale The locale for which to retrieve the display country.
	* @return The name of the country appropriate to the given locale.
	* @throws NullPointerException if {@code inLocale} is {@code null}
	*/
	public String getDisplayCountry(Locale inLocale) {
	return getDisplayString(baseLocale.getRegion(), null, inLocale, DISPLAY_COUNTRY);
	}

	private String getDisplayString(String code, String cat, Locale inLocale, int type) {
	Objects.requireNonNull(inLocale);
	Objects.requireNonNull(code);

	if (code.isEmpty()) {
	return "";
	}

	LocaleServiceProviderPool pool =
	LocaleServiceProviderPool.getPool(LocaleNameProvider.class);
	String rbKey = (type == DISPLAY_VARIANT ? "%%"+code : code);
	String result = pool.getLocalizedObject(
	LocaleNameGetter.INSTANCE,
	inLocale, rbKey, type, code, cat);
	return result != null ? result : code;
	}

	/**
	* Returns a name for the locale's variant code that is appropriate for display to the
	* user. If possible, the name will be localized for the default
	* {@link Locale.Category#DISPLAY DISPLAY} locale. If the locale
	* doesn't specify a variant code, this function returns the empty string.
	*
	* @return The name of the display variant code appropriate to the locale.
	*/
	public final String getDisplayVariant() {
	return getDisplayVariant(getDefault(Category.DISPLAY));
	}

	/**
	* Returns a name for the locale's variant code that is appropriate for display to the
	* user. If possible, the name will be localized for inLocale. If the locale
	* doesn't specify a variant code, this function returns the empty string.
	*
	* @param inLocale The locale for which to retrieve the display variant code.
	* @return The name of the display variant code appropriate to the given locale.
	* @throws NullPointerException if {@code inLocale} is {@code null}
	*/
	public String getDisplayVariant(Locale inLocale) {
	if (baseLocale.getVariant().isEmpty())
	return "";

	LocaleResources lr = LocaleProviderAdapter
	.getResourceBundleBased()
	.getLocaleResources(inLocale);

	String names[] = getDisplayVariantArray(inLocale);

	// Get the localized patterns for formatting a list, and use
	// them to format the list.
	return formatList(names,
	lr.getLocaleName("ListCompositionPattern"));
	}

	/**
	* Returns a name for the locale that is appropriate for display to the
	* user. This will be the values returned by getDisplayLanguage(),
	* getDisplayScript(), getDisplayCountry(), getDisplayVariant() and
	* optional <a href="./Locale.html#def_locale_extension">Unicode extensions</a>
	* assembled into a single string. The non-empty values are used in order, with
	* the second and subsequent names in parentheses. For example:
	* <blockquote>
	* language (script, country, variant(, extension)*)<br>
	* language (country(, extension)*)<br>
	* language (variant(, extension)*)<br>
	* script (country(, extension)*)<br>
	* country (extension)*<br>
	* </blockquote>
	* depending on which fields are specified in the locale. The field
	* separator in the above parentheses, denoted as a comma character, may
	* be localized depending on the locale. If the language, script, country,
	* and variant fields are all empty, this function returns the empty string.
	*
	* @return The name of the locale appropriate to display.
	*/
	public final String getDisplayName() {
	return getDisplayName(getDefault(Category.DISPLAY));
	}

	/**
	* Returns a name for the locale that is appropriate for display
	* to the user. This will be the values returned by
	* getDisplayLanguage(), getDisplayScript(),getDisplayCountry()
	* getDisplayVariant(), and optional <a href="./Locale.html#def_locale_extension">
	* Unicode extensions</a> assembled into a single string. The non-empty
	* values are used in order, with the second and subsequent names in
	* parentheses. For example:
	* <blockquote>
	* language (script, country, variant(, extension)*)<br>
	* language (country(, extension)*)<br>
	* language (variant(, extension)*)<br>
	* script (country(, extension)*)<br>
	* country (extension)*<br>
	* </blockquote>
	* depending on which fields are specified in the locale. The field
	* separator in the above parentheses, denoted as a comma character, may
	* be localized depending on the locale. If the language, script, country,
	* and variant fields are all empty, this function returns the empty string.
	*
	* @param inLocale The locale for which to retrieve the display name.
	* @return The name of the locale appropriate to display.
	* @throws NullPointerException if {@code inLocale} is {@code null}
	*/
	public String getDisplayName(Locale inLocale) {
	LocaleResources lr = LocaleProviderAdapter
	.getResourceBundleBased()
	.getLocaleResources(inLocale);

	String languageName = getDisplayLanguage(inLocale);
	String scriptName = getDisplayScript(inLocale);
	String countryName = getDisplayCountry(inLocale);
	String[] variantNames = getDisplayVariantArray(inLocale);

	// Get the localized patterns for formatting a display name.
	String displayNamePattern = lr.getLocaleName("DisplayNamePattern");
	String listCompositionPattern = lr.getLocaleName("ListCompositionPattern");

	// The display name consists of a main name, followed by qualifiers.
	// Typically, the format is "MainName (Qualifier, Qualifier)" but this
	// depends on what pattern is stored in the display locale.
	String mainName;
	String[] qualifierNames;

	// The main name is the language, or if there is no language, the script,
	// then if no script, the country. If there is no language/script/country
	// (an anomalous situation) then the display name is simply the variant's
	// display name.
	if (languageName.isEmpty() && scriptName.isEmpty() && countryName.isEmpty()) {
	if (variantNames.length == 0) {
	return "";
	} else {
	return formatList(variantNames, listCompositionPattern);
	}
	}
	ArrayList<String> names = new ArrayList<>(4);
	if (!languageName.isEmpty()) {
	names.add(languageName);
	}
	if (!scriptName.isEmpty()) {
	names.add(scriptName);
	}
	if (!countryName.isEmpty()) {
	names.add(countryName);
	}
	if (variantNames.length != 0) {
	names.addAll(Arrays.asList(variantNames));
	}

	// add Unicode extensions
	if (localeExtensions != null) {
	localeExtensions.getUnicodeLocaleAttributes().stream()
	.map(key -> getDisplayString(key, null, inLocale, DISPLAY_UEXT_KEY))
	.forEach(names::add);
	localeExtensions.getUnicodeLocaleKeys().stream()
	.map(key -> getDisplayKeyTypeExtensionString(key, lr, inLocale))
	.forEach(names::add);
	}

	// The first one in the main name
	mainName = names.get(0);

	// Others are qualifiers
	int numNames = names.size();
	qualifierNames = (numNames > 1) ?
	names.subList(1, numNames).toArray(new String[numNames - 1]) : new String[0];

	// Create an array whose first element is the number of remaining
	// elements. This serves as a selector into a ChoiceFormat pattern from
	// the resource. The second and third elements are the main name and
	// the qualifier; if there are no qualifiers, the third element is
	// unused by the format pattern.
	Object[] displayNames = {
	qualifierNames.length != 0 ? 2 : 1,
	mainName,
	// We could also just call formatList() and have it handle the empty
	// list case, but this is more efficient, and we want it to be
	// efficient since all the language-only locales will not have any
	// qualifiers.
	qualifierNames.length != 0 ? formatList(qualifierNames, listCompositionPattern) : null
	};

	if (displayNamePattern != null) {
	return new MessageFormat(displayNamePattern).format(displayNames);
	}
	else {
	// If we cannot get the message format pattern, then we use a simple
	// hard-coded pattern. This should not occur in practice unless the
	// installation is missing some core files (FormatData etc.).
	StringBuilder result = new StringBuilder();
	result.append((String)displayNames[1]);
	if (displayNames.length > 2) {
	result.append(" (");
	result.append((String)displayNames[2]);
	result.append(')');
	}
	return result.toString();
	}
	}

	/**
	* Overrides Cloneable.
	*/
	@Override
	public Object clone()
	{
	try {
	Locale that = (Locale)super.clone();
	return that;
	} catch (CloneNotSupportedException e) {
	throw new InternalError(e);
	}
	}

	/**
	* Override hashCode.
	* Since Locales are often used in hashtables, caches the value
	* for speed.
	*/
	@Override
	public int hashCode() {
	int hc = hashCodeValue;
	if (hc == 0) {
	hc = baseLocale.hashCode();
	if (localeExtensions != null) {
	hc ^= localeExtensions.hashCode();
	}
	hashCodeValue = hc;
	}
	return hc;
	}

	// Overrides

	/**
	* Returns true if this Locale is equal to another object. A Locale is
	* deemed equal to another Locale with identical language, script, country,
	* variant and extensions, and unequal to all other objects.
	*
	* @return true if this Locale is equal to the specified object.
	*/
	@Override
	public boolean equals(Object obj) {
	if (this == obj) // quick check
	return true;
	if (!(obj instanceof Locale))
	return false;
	BaseLocale otherBase = ((Locale)obj).baseLocale;
	if (!baseLocale.equals(otherBase)) {
	return false;
	}
	if (localeExtensions == null) {
	return ((Locale)obj).localeExtensions == null;
	}
	return localeExtensions.equals(((Locale)obj).localeExtensions);
	}

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

	private transient BaseLocale baseLocale;
	private transient LocaleExtensions localeExtensions;

	/**
	* Calculated hashcode
	*/
	private transient volatile int hashCodeValue;

	private static volatile Locale defaultLocale = initDefault();
	private static volatile Locale defaultDisplayLocale;
	private static volatile Locale defaultFormatLocale;

	private transient volatile String languageTag;

	/**
	* Return an array of the display names of the variant.
	* @param inLocale The locale for which to retrieve the display variant.
	* @return an array of display names, possible of zero length.
	*/
	private String[] getDisplayVariantArray(Locale inLocale) {
	// Split the variant name into tokens separated by '_'.
	StringTokenizer tokenizer = new StringTokenizer(baseLocale.getVariant(), "_");
	String[] names = new String[tokenizer.countTokens()];

	// For each variant token, lookup the display name. If
	// not found, use the variant name itself.
	for (int i=0; i<names.length; ++i) {
	names[i] = getDisplayString(tokenizer.nextToken(), null,
	inLocale, DISPLAY_VARIANT);
	}

	return names;
	}

	private String getDisplayKeyTypeExtensionString(String key, LocaleResources lr, Locale inLocale) {
	String type = localeExtensions.getUnicodeLocaleType(key);
	String ret = getDisplayString(type, key, inLocale, DISPLAY_UEXT_TYPE);

	if (ret == null \|\| ret.equals(type)) {
	// no localization for this type. try combining key/type separately
	String displayType = type;
	switch (key) {
	case "cu":
	displayType = lr.getCurrencyName(type.toLowerCase(Locale.ROOT));
	break;
	case "rg":
	if (type != null &&
	// UN M.49 code should not be allowed here
	type.matches("^[a-zA-Z]{2}[zZ]{4}$")) {
	displayType = lr.getLocaleName(type.substring(0, 2).toUpperCase(Locale.ROOT));
	}
	break;
	case "tz":
	displayType = TimeZoneNameUtility.convertLDMLShortID(type)
	.map(id -> TimeZoneNameUtility.retrieveGenericDisplayName(id, TimeZone.LONG, inLocale))
	.orElse(type);
	break;
	}
	ret = MessageFormat.format(lr.getLocaleName("ListKeyTypePattern"),
	getDisplayString(key, null, inLocale, DISPLAY_UEXT_KEY),
	Optional.ofNullable(displayType).orElse(type));
	}

	return ret;
	}

	/**
	* Format a list using given pattern strings.
	* If either of the patterns is null, then a the list is
	* formatted by concatenation with the delimiter ','.
	* @param stringList the list of strings to be formatted.
	* and formatting them into a list.
	* @param pattern should take 2 arguments for reduction
	* @return a string representing the list.
	*/
	private static String formatList(String[] stringList, String pattern) {
	// If we have no list patterns, compose the list in a simple,
	// non-localized way.
	if (pattern == null) {
	return Arrays.stream(stringList).collect(Collectors.joining(","));
	}

	return switch (stringList.length) {
	case 0 -> "";
	case 1 -> stringList[0];
	default -> Arrays.stream(stringList).reduce("",
	(s1, s2) -> {
	if (s1.isEmpty()) {
	return s2;
	}
	if (s2.isEmpty()) {
	return s1;
	}
	return MessageFormat.format(pattern, s1, s2);
	});
	};
	}

	// Duplicate of sun.util.locale.UnicodeLocaleExtension.isKey in order to
	// avoid its class loading.
	private static boolean isUnicodeExtensionKey(String s) {
	// 2alphanum
	return (s.length() == 2) && LocaleUtils.isAlphaNumericString(s);
	}

	/**
	* @serialField language String
	* language subtag in lower case.
	* (See <a href="java.base/java/util/Locale.html#getLanguage()">getLanguage()</a>)
	* @serialField country String
	* country subtag in upper case.
	* (See <a href="java.base/java/util/Locale.html#getCountry()">getCountry()</a>)
	* @serialField variant String
	* variant subtags separated by LOWLINE characters.
	* (See <a href="java.base/java/util/Locale.html#getVariant()">getVariant()</a>)
	* @serialField hashcode int
	* deprecated, for forward compatibility only
	* @serialField script String
	* script subtag in title case
	* (See <a href="java.base/java/util/Locale.html#getScript()">getScript()</a>)
	* @serialField extensions String
	* canonical representation of extensions, that is,
	* BCP47 extensions in alphabetical order followed by
	* BCP47 private use subtags, all in lower case letters
	* separated by HYPHEN-MINUS characters.
	* (See <a href="java.base/java/util/Locale.html#getExtensionKeys()">getExtensionKeys()</a>,
	* <a href="java.base/java/util/Locale.html#getExtension(char)">getExtension(char)</a>)
	*/
	@java.io.Serial
	private static final ObjectStreamField[] serialPersistentFields = {
	new ObjectStreamField("language", String.class),
	new ObjectStreamField("country", String.class),
	new ObjectStreamField("variant", String.class),
	new ObjectStreamField("hashcode", int.class),
	new ObjectStreamField("script", String.class),
	new ObjectStreamField("extensions", String.class),
	};

	/**
	* Serializes this {@code Locale} to the specified {@code ObjectOutputStream}.
	* @param out the {@code ObjectOutputStream} to write
	* @throws IOException
	* @since 1.7
	*/
	@java.io.Serial
	private void writeObject(ObjectOutputStream out) throws IOException {
	ObjectOutputStream.PutField fields = out.putFields();
	fields.put("language", baseLocale.getLanguage());
	fields.put("script", baseLocale.getScript());
	fields.put("country", baseLocale.getRegion());
	fields.put("variant", baseLocale.getVariant());
	fields.put("extensions", localeExtensions == null ? "" : localeExtensions.getID());
	fields.put("hashcode", -1); // place holder just for backward support
	out.writeFields();
	}

	/**
	* Deserializes this {@code Locale}.
	* @param in the {@code ObjectInputStream} to read
	* @throws IOException
	* @throws ClassNotFoundException
	* @throws IllformedLocaleException
	* @since 1.7
	*/
	@java.io.Serial
	private void readObject(ObjectInputStream in) throws IOException, ClassNotFoundException {
	ObjectInputStream.GetField fields = in.readFields();
	String language = (String)fields.get("language", "");
	String script = (String)fields.get("script", "");
	String country = (String)fields.get("country", "");
	String variant = (String)fields.get("variant", "");
	String extStr = (String)fields.get("extensions", "");

	baseLocale = BaseLocale.getInstance(convertOldISOCodes(language), script, country, variant);
	if (!extStr.isEmpty()) {
	try {
	InternalLocaleBuilder bldr = new InternalLocaleBuilder();
	bldr.setExtensions(extStr);
	localeExtensions = bldr.getLocaleExtensions();
	} catch (LocaleSyntaxException e) {
	throw new IllformedLocaleException(e.getMessage());
	}
	} else {
	localeExtensions = null;
	}
	}

	/**
	* Returns a cached {@code Locale} instance equivalent to
	* the deserialized {@code Locale}. When serialized
	* language, country and variant fields read from the object data stream
	* are exactly "ja", "JP", "JP" or "th", "TH", "TH" and script/extensions
	* fields are empty, this method supplies {@code UNICODE_LOCALE_EXTENSION}
	* "ca"/"japanese" (calendar type is "japanese") or "nu"/"thai" (number script
	* type is "thai"). See <a href="Locale.html#special_cases_constructor">Special Cases</a>
	* for more information.
	*
	* @return an instance of {@code Locale} equivalent to
	* the deserialized {@code Locale}.
	* @throws java.io.ObjectStreamException
	*/
	@java.io.Serial
	private Object readResolve() throws java.io.ObjectStreamException {
	return getInstance(baseLocale.getLanguage(), baseLocale.getScript(),
	baseLocale.getRegion(), baseLocale.getVariant(), localeExtensions);
	}

	private static volatile String[] isoLanguages;

	private static volatile String[] isoCountries;

	private static String convertOldISOCodes(String language) {
	// we accept both the old and the new ISO codes for the languages whose ISO
	// codes have changed, but we always store the NEW code, unless the property
	// java.locale.useOldISOCodes is set to "true"
	return BaseLocale.convertOldISOCodes(LocaleUtils.toLowerString(language).intern());
	}

	private static LocaleExtensions getCompatibilityExtensions(String language,
	String script,
	String country,
	String variant) {
	LocaleExtensions extensions = null;
	// Special cases for backward compatibility support
	if (LocaleUtils.caseIgnoreMatch(language, "ja")
	&& script.isEmpty()
	&& LocaleUtils.caseIgnoreMatch(country, "jp")
	&& "JP".equals(variant)) {
	// ja_JP_JP -> u-ca-japanese (calendar = japanese)
	extensions = LocaleExtensions.CALENDAR_JAPANESE;
	} else if (LocaleUtils.caseIgnoreMatch(language, "th")
	&& script.isEmpty()
	&& LocaleUtils.caseIgnoreMatch(country, "th")
	&& "TH".equals(variant)) {
	// th_TH_TH -> u-nu-thai (numbersystem = thai)
	extensions = LocaleExtensions.NUMBER_THAI;
	}
	return extensions;
	}

	/**
	* Obtains a localized locale names from a LocaleNameProvider
	* implementation.
	*/
	private static class LocaleNameGetter
	implements LocaleServiceProviderPool.LocalizedObjectGetter<LocaleNameProvider, String> {
	private static final LocaleNameGetter INSTANCE = new LocaleNameGetter();

	@Override
	public String getObject(LocaleNameProvider localeNameProvider,
	Locale locale,
	String key,
	Object... params) {
	assert params.length == 3;
	int type = (Integer)params[0];
	String code = (String)params[1];
	String cat = (String)params[2];

	switch(type) {
	case DISPLAY_LANGUAGE:
	return localeNameProvider.getDisplayLanguage(code, locale);
	case DISPLAY_COUNTRY:
	return localeNameProvider.getDisplayCountry(code, locale);
	case DISPLAY_VARIANT:
	return localeNameProvider.getDisplayVariant(code, locale);
	case DISPLAY_SCRIPT:
	return localeNameProvider.getDisplayScript(code, locale);
	case DISPLAY_UEXT_KEY:
	return localeNameProvider.getDisplayUnicodeExtensionKey(code, locale);
	case DISPLAY_UEXT_TYPE:
	return localeNameProvider.getDisplayUnicodeExtensionType(code, cat, locale);
	default:
	assert false; // shouldn't happen
	}

	return null;
	}
	}

	/**
	* Enum for locale categories. These locale categories are used to get/set
	* the default locale for the specific functionality represented by the
	* category.
	*
	* @see #getDefault(Locale.Category)
	* @see #setDefault(Locale.Category, Locale)
	* @since 1.7
	*/
	public enum Category {

	/**
	* Category used to represent the default locale for
	* displaying user interfaces.
	*/
	DISPLAY("user.language.display",
	"user.script.display",
	"user.country.display",
	"user.variant.display",
	"user.extensions.display"),

	/**
	* Category used to represent the default locale for
	* formatting dates, numbers, and/or currencies.
	*/
	FORMAT("user.language.format",
	"user.script.format",
	"user.country.format",
	"user.variant.format",
	"user.extensions.format");

	Category(String languageKey, String scriptKey, String countryKey,
	String variantKey, String extensionsKey) {
	this.languageKey = languageKey;
	this.scriptKey = scriptKey;
	this.countryKey = countryKey;
	this.variantKey = variantKey;
	this.extensionsKey = extensionsKey;
	}

	final String languageKey;
	final String scriptKey;
	final String countryKey;
	final String variantKey;
	final String extensionsKey;
	}

	/**
	* {@code Builder} is used to build instances of {@code Locale}
	* from values configured by the setters. Unlike the {@code Locale}
	* constructors, the {@code Builder} checks if a value configured by a
	* setter satisfies the syntax requirements defined by the {@code Locale}
	* class. A {@code Locale} object created by a {@code Builder} is
	* well-formed and can be transformed to a well-formed IETF BCP 47 language tag
	* without losing information.
	*
	* <p><b>Note:</b> The {@code Locale} class does not provide any
	* syntactic restrictions on variant, while BCP 47 requires each variant
	* subtag to be 5 to 8 alphanumerics or a single numeric followed by 3
	* alphanumerics. The method {@code setVariant} throws
	* {@code IllformedLocaleException} for a variant that does not satisfy
	* this restriction. If it is necessary to support such a variant, use a
	* Locale constructor. However, keep in mind that a {@code Locale}
	* object created this way might lose the variant information when
	* transformed to a BCP 47 language tag.
	*
	* <p>The following example shows how to create a {@code Locale} object
	* with the {@code Builder}.
	* <blockquote>
	* <pre>
	* Locale aLocale = new Builder().setLanguage("sr").setScript("Latn").setRegion("RS").build();
	* </pre>
	* </blockquote>
	*
	* <p>Builders can be reused; {@code clear()} resets all
	* fields to their default values.
	*
	* @see Locale#forLanguageTag
	* @since 1.7
	*/
	public static final class Builder {
	private final InternalLocaleBuilder localeBuilder;

	/**
	* Constructs an empty Builder. The default value of all
	* fields, extensions, and private use information is the
	* empty string.
	*/
	public Builder() {
	localeBuilder = new InternalLocaleBuilder();
	}

	/**
	* Resets the {@code Builder} to match the provided
	* {@code locale}. Existing state is discarded.
	*
	* <p>All fields of the locale must be well-formed, see {@link Locale}.
	*
	* <p>Locales with any ill-formed fields cause
	* {@code IllformedLocaleException} to be thrown, except for the
	* following three cases which are accepted for compatibility
	* reasons:<ul>
	* <li>Locale("ja", "JP", "JP") is treated as "ja-JP-u-ca-japanese"
	* <li>Locale("th", "TH", "TH") is treated as "th-TH-u-nu-thai"
	* <li>Locale("no", "NO", "NY") is treated as "nn-NO"</ul>
	*
	* @param locale the locale
	* @return This builder.
	* @throws IllformedLocaleException if {@code locale} has
	* any ill-formed fields.
	* @throws NullPointerException if {@code locale} is null.
	*/
	public Builder setLocale(Locale locale) {
	try {
	localeBuilder.setLocale(locale.baseLocale, locale.localeExtensions);
	} catch (LocaleSyntaxException e) {
	throw new IllformedLocaleException(e.getMessage(), e.getErrorIndex());
	}
	return this;
	}

	/**
	* Resets the Builder to match the provided IETF BCP 47
	* language tag. Discards the existing state. Null and the
	* empty string cause the builder to be reset, like {@link
	* #clear}. Legacy tags (see {@link
	* Locale#forLanguageTag}) are converted to their canonical
	* form before being processed. Otherwise, the language tag
	* must be well-formed (see {@link Locale}) or an exception is
	* thrown (unlike {@code Locale.forLanguageTag}, which
	* just discards ill-formed and following portions of the
	* tag).
	*
	* @param languageTag the language tag
	* @return This builder.
	* @throws IllformedLocaleException if {@code languageTag} is ill-formed
	* @see Locale#forLanguageTag(String)
	*/
	public Builder setLanguageTag(String languageTag) {
	ParseStatus sts = new ParseStatus();
	LanguageTag tag = LanguageTag.parse(languageTag, sts);
	if (sts.isError()) {
	throw new IllformedLocaleException(sts.getErrorMessage(), sts.getErrorIndex());
	}
	localeBuilder.setLanguageTag(tag);
	return this;
	}

	/**
	* Sets the language. If {@code language} is the empty string or
	* null, the language in this {@code Builder} is removed. Otherwise,
	* the language must be <a href="./Locale.html#def_language">well-formed</a>
	* or an exception is thrown.
	*
	* <p>The typical language value is a two or three-letter language
	* code as defined in ISO639.
	*
	* @param language the language
	* @return This builder.
	* @throws IllformedLocaleException if {@code language} is ill-formed
	*/
	public Builder setLanguage(String language) {
	try {
	localeBuilder.setLanguage(language);
	} catch (LocaleSyntaxException e) {
	throw new IllformedLocaleException(e.getMessage(), e.getErrorIndex());
	}
	return this;
	}

	/**
	* Sets the script. If {@code script} is null or the empty string,
	* the script in this {@code Builder} is removed.
	* Otherwise, the script must be <a href="./Locale.html#def_script">well-formed</a> or an
	* exception is thrown.
	*
	* <p>The typical script value is a four-letter script code as defined by ISO 15924.
	*
	* @param script the script
	* @return This builder.
	* @throws IllformedLocaleException if {@code script} is ill-formed
	*/
	public Builder setScript(String script) {
	try {
	localeBuilder.setScript(script);
	} catch (LocaleSyntaxException e) {
	throw new IllformedLocaleException(e.getMessage(), e.getErrorIndex());
	}
	return this;
	}

	/**
	* Sets the region. If region is null or the empty string, the region
	* in this {@code Builder} is removed. Otherwise,
	* the region must be <a href="./Locale.html#def_region">well-formed</a> or an
	* exception is thrown.
	*
	* <p>The typical region value is a two-letter ISO 3166 code or a
	* three-digit UN M.49 area code.
	*
	* <p>The country value in the {@code Locale} created by the
	* {@code Builder} is always normalized to upper case.
	*
	* @param region the region
	* @return This builder.
	* @throws IllformedLocaleException if {@code region} is ill-formed
	*/
	public Builder setRegion(String region) {
	try {
	localeBuilder.setRegion(region);
	} catch (LocaleSyntaxException e) {
	throw new IllformedLocaleException(e.getMessage(), e.getErrorIndex());
	}
	return this;
	}

	/**
	* Sets the variant. If variant is null or the empty string, the
	* variant in this {@code Builder} is removed. Otherwise, it
	* must consist of one or more <a href="./Locale.html#def_variant">well-formed</a>
	* subtags, or an exception is thrown.
	*
	* <p><b>Note:</b> This method checks if {@code variant}
	* satisfies the IETF BCP 47 variant subtag's syntax requirements,
	* and normalizes the value to lowercase letters. However,
	* the {@code Locale} class does not impose any syntactic
	* restriction on variant, and the variant value in
	* {@code Locale} is case sensitive. To set such a variant,
	* use a Locale constructor.
	*
	* @param variant the variant
	* @return This builder.
	* @throws IllformedLocaleException if {@code variant} is ill-formed
	*/
	public Builder setVariant(String variant) {
	try {
	localeBuilder.setVariant(variant);
	} catch (LocaleSyntaxException e) {
	throw new IllformedLocaleException(e.getMessage(), e.getErrorIndex());
	}
	return this;
	}

	/**
	* Sets the extension for the given key. If the value is null or the
	* empty string, the extension is removed. Otherwise, the extension
	* must be <a href="./Locale.html#def_extensions">well-formed</a> or an exception
	* is thrown.
	*
	* <p><b>Note:</b> The key {@link Locale#UNICODE_LOCALE_EXTENSION
	* UNICODE_LOCALE_EXTENSION} ('u') is used for the Unicode locale extension.
	* Setting a value for this key replaces any existing Unicode locale key/type
	* pairs with those defined in the extension.
	*
	* <p><b>Note:</b> The key {@link Locale#PRIVATE_USE_EXTENSION
	* PRIVATE_USE_EXTENSION} ('x') is used for the private use code. To be
	* well-formed, the value for this key needs only to have subtags of one to
	* eight alphanumeric characters, not two to eight as in the general case.
	*
	* @param key the extension key
	* @param value the extension value
	* @return This builder.
	* @throws IllformedLocaleException if {@code key} is illegal
	* or {@code value} is ill-formed
	* @see #setUnicodeLocaleKeyword(String, String)
	*/
	public Builder setExtension(char key, String value) {
	try {
	localeBuilder.setExtension(key, value);
	} catch (LocaleSyntaxException e) {
	throw new IllformedLocaleException(e.getMessage(), e.getErrorIndex());
	}
	return this;
	}

	/**
	* Sets the Unicode locale keyword type for the given key. If the type
	* is null, the Unicode keyword is removed. Otherwise, the key must be
	* non-null and both key and type must be <a
	* href="./Locale.html#def_locale_extension">well-formed</a> or an exception
	* is thrown.
	*
	* <p>Keys and types are converted to lower case.
	*
	* <p><b>Note</b>:Setting the 'u' extension via {@link #setExtension}
	* replaces all Unicode locale keywords with those defined in the
	* extension.
	*
	* @param key the Unicode locale key
	* @param type the Unicode locale type
	* @return This builder.
	* @throws IllformedLocaleException if {@code key} or {@code type}
	* is ill-formed
	* @throws NullPointerException if {@code key} is null
	* @see #setExtension(char, String)
	*/
	public Builder setUnicodeLocaleKeyword(String key, String type) {
	try {
	localeBuilder.setUnicodeLocaleKeyword(key, type);
	} catch (LocaleSyntaxException e) {
	throw new IllformedLocaleException(e.getMessage(), e.getErrorIndex());
	}
	return this;
	}

	/**
	* Adds a unicode locale attribute, if not already present, otherwise
	* has no effect. The attribute must not be null and must be <a
	* href="./Locale.html#def_locale_extension">well-formed</a> or an exception
	* is thrown.
	*
	* @param attribute the attribute
	* @return This builder.
	* @throws NullPointerException if {@code attribute} is null
	* @throws IllformedLocaleException if {@code attribute} is ill-formed
	* @see #setExtension(char, String)
	*/
	public Builder addUnicodeLocaleAttribute(String attribute) {
	try {
	localeBuilder.addUnicodeLocaleAttribute(attribute);
	} catch (LocaleSyntaxException e) {
	throw new IllformedLocaleException(e.getMessage(), e.getErrorIndex());
	}
	return this;
	}

	/**
	* Removes a unicode locale attribute, if present, otherwise has no
	* effect. The attribute must not be null and must be <a
	* href="./Locale.html#def_locale_extension">well-formed</a> or an exception
	* is thrown.
	*
	* <p>Attribute comparison for removal is case-insensitive.
	*
	* @param attribute the attribute
	* @return This builder.
	* @throws NullPointerException if {@code attribute} is null
	* @throws IllformedLocaleException if {@code attribute} is ill-formed
	* @see #setExtension(char, String)
	*/
	public Builder removeUnicodeLocaleAttribute(String attribute) {
	Objects.requireNonNull(attribute);
	try {
	localeBuilder.removeUnicodeLocaleAttribute(attribute);
	} catch (LocaleSyntaxException e) {
	throw new IllformedLocaleException(e.getMessage(), e.getErrorIndex());
	}
	return this;
	}

	/**
	* Resets the builder to its initial, empty state.
	*
	* @return This builder.
	*/
	public Builder clear() {
	localeBuilder.clear();
	return this;
	}

	/**
	* Resets the extensions to their initial, empty state.
	* Language, script, region and variant are unchanged.
	*
	* @return This builder.
	* @see #setExtension(char, String)
	*/
	public Builder clearExtensions() {
	localeBuilder.clearExtensions();
	return this;
	}

	/**
	* Returns an instance of {@code Locale} created from the fields set
	* on this builder.
	*
	* <p>This applies the conversions listed in {@link Locale#forLanguageTag}
	* when constructing a Locale. (Legacy tags are handled in
	* {@link #setLanguageTag}.)
	*
	* @return A Locale.
	*/
	public Locale build() {
	BaseLocale baseloc = localeBuilder.getBaseLocale();
	LocaleExtensions extensions = localeBuilder.getLocaleExtensions();
	if (extensions == null && !baseloc.getVariant().isEmpty()) {
	extensions = getCompatibilityExtensions(baseloc.getLanguage(), baseloc.getScript(),
	baseloc.getRegion(), baseloc.getVariant());
	}
	return Locale.getInstance(baseloc, extensions);
	}
	}

	/**
	* This enum provides constants to select a filtering mode for locale
	* matching. Refer to <a href="http://tools.ietf.org/html/rfc4647">RFC 4647
	* Matching of Language Tags</a> for details.
	*
	* <p>As an example, think of two Language Priority Lists each of which
	* includes only one language range and a set of following language tags:
	*
	* <pre>
	* de (German)
	* de-DE (German, Germany)
	* de-Deva (German, in Devanagari script)
	* de-Deva-DE (German, in Devanagari script, Germany)
	* de-DE-1996 (German, Germany, orthography of 1996)
	* de-Latn-DE (German, in Latin script, Germany)
	* de-Latn-DE-1996 (German, in Latin script, Germany, orthography of 1996)
	* </pre>
	*
	* The filtering method will behave as follows:
	*
	* <table class="striped">
	* <caption>Filtering method behavior</caption>
	* <thead>
	* <tr>
	* <th scope="col">Filtering Mode</th>
	* <th scope="col">Language Priority List: {@code "de-DE"}</th>
	* <th scope="col">Language Priority List: {@code "de-*-DE"}</th>
	* </tr>
	* </thead>
	* <tbody>
	* <tr>
	* <th scope="row" style="vertical-align:top">
	* {@link FilteringMode#AUTOSELECT_FILTERING AUTOSELECT_FILTERING}
	* </th>
	* <td style="vertical-align:top">
	* Performs <em>basic</em> filtering and returns {@code "de-DE"} and
	* {@code "de-DE-1996"}.
	* </td>
	* <td style="vertical-align:top">
	* Performs <em>extended</em> filtering and returns {@code "de-DE"},
	* {@code "de-Deva-DE"}, {@code "de-DE-1996"}, {@code "de-Latn-DE"}, and
	* {@code "de-Latn-DE-1996"}.
	* </td>
	* </tr>
	* <tr>
	* <th scope="row" style="vertical-align:top">
	* {@link FilteringMode#EXTENDED_FILTERING EXTENDED_FILTERING}
	* </th>
	* <td style="vertical-align:top">
	* Performs <em>extended</em> filtering and returns {@code "de-DE"},
	* {@code "de-Deva-DE"}, {@code "de-DE-1996"}, {@code "de-Latn-DE"}, and
	* {@code "de-Latn-DE-1996"}.
	* </td>
	* <td style="vertical-align:top">Same as above.</td>
	* </tr>
	* <tr>
	* <th scope="row" style="vertical-align:top">
	* {@link FilteringMode#IGNORE_EXTENDED_RANGES IGNORE_EXTENDED_RANGES}
	* </th>
	* <td style="vertical-align:top">
	* Performs <em>basic</em> filtering and returns {@code "de-DE"} and
	* {@code "de-DE-1996"}.
	* </td>
	* <td style="vertical-align:top">
	* Performs <em>basic</em> filtering and returns {@code null} because
	* nothing matches.
	* </td>
	* </tr>
	* <tr>
	* <th scope="row" style="vertical-align:top">
	* {@link FilteringMode#MAP_EXTENDED_RANGES MAP_EXTENDED_RANGES}
	* </th>
	* <td style="vertical-align:top">Same as above.</td>
	* <td style="vertical-align:top">
	* Performs <em>basic</em> filtering and returns {@code "de-DE"} and
	* {@code "de-DE-1996"} because {@code "de-*-DE"} is mapped to
	* {@code "de-DE"}.
	* </td>
	* </tr>
	* <tr>
	* <th scope="row" style="vertical-align:top">
	* {@link FilteringMode#REJECT_EXTENDED_RANGES REJECT_EXTENDED_RANGES}
	* </th>
	* <td style="vertical-align:top">Same as above.</td>
	* <td style="vertical-align:top">
	* Throws {@link IllegalArgumentException} because {@code "de-*-DE"} is
	* not a valid basic language range.
	* </td>
	* </tr>
	* </tbody>
	* </table>
	*
	* @see #filter(List, Collection, FilteringMode)
	* @see #filterTags(List, Collection, FilteringMode)
	*
	* @since 1.8
	*/
	public static enum FilteringMode {
	/**
	* Specifies automatic filtering mode based on the given Language
	* Priority List consisting of language ranges. If all of the ranges
	* are basic, basic filtering is selected. Otherwise, extended
	* filtering is selected.
	*/
	AUTOSELECT_FILTERING,

	/**
	* Specifies extended filtering.
	*/
	EXTENDED_FILTERING,

	/**
	* Specifies basic filtering: Note that any extended language ranges
	* included in the given Language Priority List are ignored.
	*/
	IGNORE_EXTENDED_RANGES,

	/**
	* Specifies basic filtering: If any extended language ranges are
	* included in the given Language Priority List, they are mapped to the
	* basic language range. Specifically, a language range starting with a
	* subtag {@code ""} is treated as a language range {@code ""}. For
	* example, {@code "-US"} is treated as {@code ""}. If {@code "*"} is
	* not the first subtag, {@code "*"} and extra {@code "-"} are removed.
	* For example, {@code "ja-*-JP"} is mapped to {@code "ja-JP"}.
	*/
	MAP_EXTENDED_RANGES,

	/**
	* Specifies basic filtering: If any extended language ranges are
	* included in the given Language Priority List, the list is rejected
	* and the filtering method throws {@link IllegalArgumentException}.
	*/
	REJECT_EXTENDED_RANGES
	};

	/**
	* This class expresses a <em>Language Range</em> defined in
	* <a href="http://tools.ietf.org/html/rfc4647">RFC 4647 Matching of
	* Language Tags</a>. A language range is an identifier which is used to
	* select language tag(s) meeting specific requirements by using the
	* mechanisms described in <a href="Locale.html#LocaleMatching">Locale
	* Matching</a>. A list which represents a user's preferences and consists
	* of language ranges is called a <em>Language Priority List</em>.
	*
	* <p>There are two types of language ranges: basic and extended. In RFC
	* 4647, the syntax of language ranges is expressed in
	* <a href="http://tools.ietf.org/html/rfc4234">ABNF</a> as follows:
	* <blockquote>
	* <pre>
	* basic-language-range = (18ALPHA ("-" 18alphanum)) / ""
	* extended-language-range = (18ALPHA / "")
	* ("-" (18alphanum / "*"))
	* alphanum = ALPHA / DIGIT
	* </pre>
	* </blockquote>
	* For example, {@code "en"} (English), {@code "ja-JP"} (Japanese, Japan),
	* {@code "*"} (special language range which matches any language tag) are
	* basic language ranges, whereas {@code "*-CH"} (any languages,
	* Switzerland), {@code "es-*"} (Spanish, any regions), and
	* {@code "zh-Hant-*"} (Traditional Chinese, any regions) are extended
	* language ranges.
	*
	* @see #filter
	* @see #filterTags
	* @see #lookup
	* @see #lookupTag
	*
	* @since 1.8
	*/
	public static final class LanguageRange {

	/**
	* A constant holding the maximum value of weight, 1.0, which indicates
	* that the language range is a good fit for the user.
	*/
	public static final double MAX_WEIGHT = 1.0;

	/**
	* A constant holding the minimum value of weight, 0.0, which indicates
	* that the language range is not a good fit for the user.
	*/
	public static final double MIN_WEIGHT = 0.0;

	private final String range;
	private final double weight;

	private volatile int hash;

	/**
	* Constructs a {@code LanguageRange} using the given {@code range}.
	* Note that no validation is done against the IANA Language Subtag
	* Registry at time of construction.
	*
	* <p>This is equivalent to {@code LanguageRange(range, MAX_WEIGHT)}.
	*
	* @param range a language range
	* @throws NullPointerException if the given {@code range} is
	* {@code null}
	* @throws IllegalArgumentException if the given {@code range} does not
	* comply with the syntax of the language range mentioned in RFC 4647
	*/
	public LanguageRange(String range) {
	this(range, MAX_WEIGHT);
	}

	/**
	* Constructs a {@code LanguageRange} using the given {@code range} and
	* {@code weight}. Note that no validation is done against the IANA
	* Language Subtag Registry at time of construction.
	*
	* @param range a language range
	* @param weight a weight value between {@code MIN_WEIGHT} and
	* {@code MAX_WEIGHT}
	* @throws NullPointerException if the given {@code range} is
	* {@code null}
	* @throws IllegalArgumentException if the given {@code range} does not
	* comply with the syntax of the language range mentioned in RFC 4647
	* or if the given {@code weight} is less than {@code MIN_WEIGHT}
	* or greater than {@code MAX_WEIGHT}
	*/
	public LanguageRange(String range, double weight) {
	if (range == null) {
	throw new NullPointerException();
	}
	if (weight < MIN_WEIGHT \|\| weight > MAX_WEIGHT) {
	throw new IllegalArgumentException("weight=" + weight);
	}

	range = range.toLowerCase(Locale.ROOT);

	// Do syntax check.
	boolean isIllFormed = false;
	String[] subtags = range.split("-");
	if (isSubtagIllFormed(subtags[0], true)
	\|\| range.endsWith("-")) {
	isIllFormed = true;
	} else {
	for (int i = 1; i < subtags.length; i++) {
	if (isSubtagIllFormed(subtags[i], false)) {
	isIllFormed = true;
	break;
	}
	}
	}
	if (isIllFormed) {
	throw new IllegalArgumentException("range=" + range);
	}

	this.range = range;
	this.weight = weight;
	}

	private static boolean isSubtagIllFormed(String subtag,
	boolean isFirstSubtag) {
	if (subtag.isEmpty() \|\| subtag.length() > 8) {
	return true;
	} else if (subtag.equals("*")) {
	return false;
	}
	char[] charArray = subtag.toCharArray();
	if (isFirstSubtag) { // ALPHA
	for (char c : charArray) {
	if (c < 'a' \|\| c > 'z') {
	return true;
	}
	}
	} else { // ALPHA / DIGIT
	for (char c : charArray) {
	if (c < '0' \|\| (c > '9' && c < 'a') \|\| c > 'z') {
	return true;
	}
	}
	}
	return false;
	}

	/**
	* Returns the language range of this {@code LanguageRange}.
	*
	* @return the language range.
	*/
	public String getRange() {
	return range;
	}

	/**
	* Returns the weight of this {@code LanguageRange}.
	*
	* @return the weight value.
	*/
	public double getWeight() {
	return weight;
	}

	/**
	* Parses the given {@code ranges} to generate a Language Priority List.
	*
	* <p>This method performs a syntactic check for each language range in
	* the given {@code ranges} but doesn't do validation using the IANA
	* Language Subtag Registry.
	*
	* <p>The {@code ranges} to be given can take one of the following
	* forms:
	*
	* <pre>
	* "Accept-Language: ja,en;q=0.4" (weighted list with Accept-Language prefix)
	* "ja,en;q=0.4" (weighted list)
	* "ja,en" (prioritized list)
	* </pre>
	*
	* In a weighted list, each language range is given a weight value.
	* The weight value is identical to the "quality value" in
	* <a href="http://tools.ietf.org/html/rfc2616">RFC 2616</a>, and it
	* expresses how much the user prefers the language. A weight value is
	* specified after a corresponding language range followed by
	* {@code ";q="}, and the default weight value is {@code MAX_WEIGHT}
	* when it is omitted.
	*
	* <p>Unlike a weighted list, language ranges in a prioritized list
	* are sorted in the descending order based on its priority. The first
	* language range has the highest priority and meets the user's
	* preference most.
	*
	* <p>In either case, language ranges are sorted in descending order in
	* the Language Priority List based on priority or weight. If a
	* language range appears in the given {@code ranges} more than once,
	* only the first one is included on the Language Priority List.
	*
	* <p>The returned list consists of language ranges from the given
	* {@code ranges} and their equivalents found in the IANA Language
	* Subtag Registry. For example, if the given {@code ranges} is
	* {@code "Accept-Language: iw,en-us;q=0.7,en;q=0.3"}, the elements in
	* the list to be returned are:
	*
	* <pre>
	* <b>Range</b> <b>Weight</b>
	* "iw" (older tag for Hebrew) 1.0
	* "he" (new preferred code for Hebrew) 1.0
	* "en-us" (English, United States) 0.7
	* "en" (English) 0.3
	* </pre>
	*
	* Two language ranges, {@code "iw"} and {@code "he"}, have the same
	* highest priority in the list. By adding {@code "he"} to the user's
	* Language Priority List, locale-matching method can find Hebrew as a
	* matching locale (or language tag) even if the application or system
	* offers only {@code "he"} as a supported locale (or language tag).
	*
	* @param ranges a list of comma-separated language ranges or a list of
	* language ranges in the form of the "Accept-Language" header
	* defined in <a href="http://tools.ietf.org/html/rfc2616">RFC
	* 2616</a>
	* @return a Language Priority List consisting of language ranges
	* included in the given {@code ranges} and their equivalent
	* language ranges if available. The list is modifiable.
	* @throws NullPointerException if {@code ranges} is null
	* @throws IllegalArgumentException if a language range or a weight
	* found in the given {@code ranges} is ill-formed
	*/
	public static List<LanguageRange> parse(String ranges) {
	return LocaleMatcher.parse(ranges);
	}

	/**
	* Parses the given {@code ranges} to generate a Language Priority
	* List, and then customizes the list using the given {@code map}.
	* This method is equivalent to
	* {@code mapEquivalents(parse(ranges), map)}.
	*
	* @param ranges a list of comma-separated language ranges or a list
	* of language ranges in the form of the "Accept-Language" header
	* defined in <a href="http://tools.ietf.org/html/rfc2616">RFC
	* 2616</a>
	* @param map a map containing information to customize language ranges
	* @return a Language Priority List with customization. The list is
	* modifiable.
	* @throws NullPointerException if {@code ranges} is null
	* @throws IllegalArgumentException if a language range or a weight
	* found in the given {@code ranges} is ill-formed
	* @see #parse(String)
	* @see #mapEquivalents
	*/
	public static List<LanguageRange> parse(String ranges,
	Map<String, List<String>> map) {
	return mapEquivalents(parse(ranges), map);
	}

	/**
	* Generates a new customized Language Priority List using the given
	* {@code priorityList} and {@code map}. If the given {@code map} is
	* empty, this method returns a copy of the given {@code priorityList}.
	*
	* <p>In the map, a key represents a language range whereas a value is
	* a list of equivalents of it. {@code '*'} cannot be used in the map.
	* Each equivalent language range has the same weight value as its
	* original language range.
	*
	* <pre>
	* An example of map:
	* <b>Key</b> <b>Value</b>
	* "zh" (Chinese) "zh",
	* "zh-Hans"(Simplified Chinese)
	* "zh-HK" (Chinese, Hong Kong) "zh-HK"
	* "zh-TW" (Chinese, Taiwan) "zh-TW"
	* </pre>
	*
	* The customization is performed after modification using the IANA
	* Language Subtag Registry.
	*
	* <p>For example, if a user's Language Priority List consists of five
	* language ranges ({@code "zh"}, {@code "zh-CN"}, {@code "en"},
	* {@code "zh-TW"}, and {@code "zh-HK"}), the newly generated Language
	* Priority List which is customized using the above map example will
	* consists of {@code "zh"}, {@code "zh-Hans"}, {@code "zh-CN"},
	* {@code "zh-Hans-CN"}, {@code "en"}, {@code "zh-TW"}, and
	* {@code "zh-HK"}.
	*
	* <p>{@code "zh-HK"} and {@code "zh-TW"} aren't converted to
	* {@code "zh-Hans-HK"} nor {@code "zh-Hans-TW"} even if they are
	* included in the Language Priority List. In this example, mapping
	* is used to clearly distinguish Simplified Chinese and Traditional
	* Chinese.
	*
	* <p>If the {@code "zh"}-to-{@code "zh"} mapping isn't included in the
	* map, a simple replacement will be performed and the customized list
	* won't include {@code "zh"} and {@code "zh-CN"}.
	*
	* @param priorityList user's Language Priority List
	* @param map a map containing information to customize language ranges
	* @return a new Language Priority List with customization. The list is
	* modifiable.
	* @throws NullPointerException if {@code priorityList} is {@code null}
	* @see #parse(String, Map)
	*/
	public static List<LanguageRange> mapEquivalents(
	List<LanguageRange>priorityList,
	Map<String, List<String>> map) {
	return LocaleMatcher.mapEquivalents(priorityList, map);
	}

	/**
	* Returns a hash code value for the object.
	*
	* @return a hash code value for this object.
	*/
	@Override
	public int hashCode() {
	int h = hash;
	if (h == 0) {
	h = 17;
	h = 37*h + range.hashCode();
	long bitsWeight = Double.doubleToLongBits(weight);
	h = 37*h + (int)(bitsWeight ^ (bitsWeight >>> 32));
	if (h != 0) {
	hash = h;
	}
	}
	return h;
	}

	/**
	* Compares this object to the specified object. The result is true if
	* and only if the argument is not {@code null} and is a
	* {@code LanguageRange} object that contains the same {@code range}
	* and {@code weight} values as this object.
	*
	* @param obj the object to compare with
	* @return {@code true} if this object's {@code range} and
	* {@code weight} are the same as the {@code obj}'s; {@code false}
	* otherwise.
	*/
	@Override
	public boolean equals(Object obj) {
	if (this == obj) {
	return true;
	}
	return obj instanceof LanguageRange other
	&& range.equals(other.range)
	&& weight == other.weight;
	}

	/**
	* Returns an informative string representation of this {@code LanguageRange}
	* object, consisting of language range and weight if the range is
	* weighted and the weight is less than the max weight.
	*
	* @return a string representation of this {@code LanguageRange} object.
	*/
	@Override
	public String toString() {
	return (weight == MAX_WEIGHT) ? range : range + ";q=" + weight;
	}
	}

	/**
	* Returns a list of matching {@code Locale} instances using the filtering
	* mechanism defined in RFC 4647.
	*
	* This filter operation on the given {@code locales} ensures that only
	* unique matching locale(s) are returned.
	*
	* @param priorityList user's Language Priority List in which each language
	* tag is sorted in descending order based on priority or weight
	* @param locales {@code Locale} instances used for matching
	* @param mode filtering mode
	* @return a list of {@code Locale} instances for matching language tags
	* sorted in descending order based on priority or weight, or an empty
	* list if nothing matches. The list is modifiable.
	* @throws NullPointerException if {@code priorityList} or {@code locales}
	* is {@code null}
	* @throws IllegalArgumentException if one or more extended language ranges
	* are included in the given list when
	* {@link FilteringMode#REJECT_EXTENDED_RANGES} is specified
	*
	* @since 1.8
	*/
	public static List<Locale> filter(List<LanguageRange> priorityList,
	Collection<Locale> locales,
	FilteringMode mode) {
	return LocaleMatcher.filter(priorityList, locales, mode);
	}

	/**
	* Returns a list of matching {@code Locale} instances using the filtering
	* mechanism defined in RFC 4647. This is equivalent to
	* {@link #filter(List, Collection, FilteringMode)} when {@code mode} is
	* {@link FilteringMode#AUTOSELECT_FILTERING}.
	*
	* This filter operation on the given {@code locales} ensures that only
	* unique matching locale(s) are returned.
	*
	* @param priorityList user's Language Priority List in which each language
	* tag is sorted in descending order based on priority or weight
	* @param locales {@code Locale} instances used for matching
	* @return a list of {@code Locale} instances for matching language tags
	* sorted in descending order based on priority or weight, or an empty
	* list if nothing matches. The list is modifiable.
	* @throws NullPointerException if {@code priorityList} or {@code locales}
	* is {@code null}
	*
	* @since 1.8
	*/
	public static List<Locale> filter(List<LanguageRange> priorityList,
	Collection<Locale> locales) {
	return filter(priorityList, locales, FilteringMode.AUTOSELECT_FILTERING);
	}

	/**
	* Returns a list of matching languages tags using the basic filtering
	* mechanism defined in RFC 4647.
	*
	* This filter operation on the given {@code tags} ensures that only
	* unique matching tag(s) are returned with preserved case. In case of
	* duplicate matching tags with the case difference, the first matching
	* tag with preserved case is returned.
	* For example, "de-ch" is returned out of the duplicate matching tags
	* "de-ch" and "de-CH", if "de-ch" is checked first for matching in the
	* given {@code tags}. Note that if the given {@code tags} is an unordered
	* {@code Collection}, the returned matching tag out of duplicate tags is
	* subject to change, depending on the implementation of the
	* {@code Collection}.
	*
	* @param priorityList user's Language Priority List in which each language
	* tag is sorted in descending order based on priority or weight
	* @param tags language tags
	* @param mode filtering mode
	* @return a list of matching language tags sorted in descending order
	* based on priority or weight, or an empty list if nothing matches.
	* The list is modifiable.
	* @throws NullPointerException if {@code priorityList} or {@code tags} is
	* {@code null}
	* @throws IllegalArgumentException if one or more extended language ranges
	* are included in the given list when
	* {@link FilteringMode#REJECT_EXTENDED_RANGES} is specified
	*
	* @since 1.8
	*/
	public static List<String> filterTags(List<LanguageRange> priorityList,
	Collection<String> tags,
	FilteringMode mode) {
	return LocaleMatcher.filterTags(priorityList, tags, mode);
	}

	/**
	* Returns a list of matching languages tags using the basic filtering
	* mechanism defined in RFC 4647. This is equivalent to
	* {@link #filterTags(List, Collection, FilteringMode)} when {@code mode}
	* is {@link FilteringMode#AUTOSELECT_FILTERING}.
	*
	* This filter operation on the given {@code tags} ensures that only
	* unique matching tag(s) are returned with preserved case. In case of
	* duplicate matching tags with the case difference, the first matching
	* tag with preserved case is returned.
	* For example, "de-ch" is returned out of the duplicate matching tags
	* "de-ch" and "de-CH", if "de-ch" is checked first for matching in the
	* given {@code tags}. Note that if the given {@code tags} is an unordered
	* {@code Collection}, the returned matching tag out of duplicate tags is
	* subject to change, depending on the implementation of the
	* {@code Collection}.
	*
	* @param priorityList user's Language Priority List in which each language
	* tag is sorted in descending order based on priority or weight
	* @param tags language tags
	* @return a list of matching language tags sorted in descending order
	* based on priority or weight, or an empty list if nothing matches.
	* The list is modifiable.
	* @throws NullPointerException if {@code priorityList} or {@code tags} is
	* {@code null}
	*
	* @since 1.8
	*/
	public static List<String> filterTags(List<LanguageRange> priorityList,
	Collection<String> tags) {
	return filterTags(priorityList, tags, FilteringMode.AUTOSELECT_FILTERING);
	}

	/**
	* Returns a {@code Locale} instance for the best-matching language
	* tag using the lookup mechanism defined in RFC 4647.
	*
	* @param priorityList user's Language Priority List in which each language
	* tag is sorted in descending order based on priority or weight
	* @param locales {@code Locale} instances used for matching
	* @return the best matching {@code Locale} instance chosen based on
	* priority or weight, or {@code null} if nothing matches.
	* @throws NullPointerException if {@code priorityList} or {@code tags} is
	* {@code null}
	*
	* @since 1.8
	*/
	public static Locale lookup(List<LanguageRange> priorityList,
	Collection<Locale> locales) {
	return LocaleMatcher.lookup(priorityList, locales);
	}

	/**
	* Returns the best-matching language tag using the lookup mechanism
	* defined in RFC 4647.
	*
	* This lookup operation on the given {@code tags} ensures that the
	* first matching tag with preserved case is returned.
	*
	* @param priorityList user's Language Priority List in which each language
	* tag is sorted in descending order based on priority or weight
	* @param tags language tangs used for matching
	* @return the best matching language tag chosen based on priority or
	* weight, or {@code null} if nothing matches.
	* @throws NullPointerException if {@code priorityList} or {@code tags} is
	* {@code null}
	*
	* @since 1.8
	*/
	public static String lookupTag(List<LanguageRange> priorityList,
	Collection<String> tags) {
	return LocaleMatcher.lookupTag(priorityList, tags);
	}

	}

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