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/*
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You under the Apache License, Version 2.0
 * (the "License"); you may not use this file except in compliance with
 * the License.  You may obtain a copy of the License at
 * 
 *      http://www.apache.org/licenses/LICENSE-2.0
 * 
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package org.apache.commons.lang;

import java.util.ArrayList;
import java.util.Arrays;
import java.util.Collections;
import java.util.HashMap;
import java.util.HashSet;
import java.util.List;
import java.util.Locale;
import java.util.Map;
import java.util.Set;

/**
 *  

Operations to assist when working with a {@link Locale}.

* *

This class tries to handle null input gracefully. * An exception will not be thrown for a null input. * Each method documents its behaviour in more detail.

* * @author Apache Software Foundation * @since 2.2 * @version $Id: LocaleUtils.java 911968 2010-02-19 20:26:21Z niallp $ * * @deprecated Commons Lang 2 is in maintenance mode. Commons Lang 3 should be used instead. */ @Deprecated(since = "2021-04-30") public class LocaleUtils { /** * Unmodifiable list of available locales. */ // lazily created by availableLocaleList() private static List cAvailableLocaleList; /** * Unmodifiable set of available locales. */ // lazily created by availableLocaleSet() private static Set cAvailableLocaleSet; /** * Unmodifiable map of language locales by country. */ private static final Map cLanguagesByCountry = Collections.synchronizedMap(new HashMap()); /** * Unmodifiable map of country locales by language. */ private static final Map cCountriesByLanguage = Collections.synchronizedMap(new HashMap()); /** *

LocaleUtils instances should NOT be constructed in standard programming. * Instead, the class should be used as LocaleUtils.toLocale("en_GB");.

* *

This constructor is public to permit tools that require a JavaBean instance * to operate.

*/ public LocaleUtils() { super(); } // ----------------------------------------------------------------------- /** *

Converts a String to a Locale.

* *

This method takes the string format of a locale and creates the * locale object from it.

* *
     *   LocaleUtils.toLocale("en")         = new Locale("en", "")
     *   LocaleUtils.toLocale("en_GB")      = new Locale("en", "GB")
     *   LocaleUtils.toLocale("en_GB_xxx")  = new Locale("en", "GB", "xxx")   (#)
     * 
* *

(#) The behaviour of the JDK variant constructor changed between JDK1.3 and JDK1.4. * In JDK1.3, the constructor upper cases the variant, in JDK1.4, it doesn't. * Thus, the result from getVariant() may vary depending on your JDK.

* *

This method validates the input strictly. * The language code must be lowercase. * The country code must be uppercase. * The separator must be an underscore. * The length must be correct. *

* * @param str the locale String to convert, null returns null * @return a Locale, null if null input * @throws IllegalArgumentException if the string is an invalid format */ public static Locale toLocale(String str) { if (str == null) { return null; } int len = str.length(); if (len != 2 && len != 5 && len < 7) { throw new IllegalArgumentException("Invalid locale format: " + str); } char ch0 = str.charAt(0); char ch1 = str.charAt(1); if (ch0 < 'a' || ch0 > 'z' || ch1 < 'a' || ch1 > 'z') { throw new IllegalArgumentException("Invalid locale format: " + str); } if (len == 2) { return new Locale(str, ""); } else { if (str.charAt(2) != '_') { throw new IllegalArgumentException("Invalid locale format: " + str); } char ch3 = str.charAt(3); if (ch3 == '_') { return new Locale(str.substring(0, 2), "", str.substring(4)); } char ch4 = str.charAt(4); if (ch3 < 'A' || ch3 > 'Z' || ch4 < 'A' || ch4 > 'Z') { throw new IllegalArgumentException("Invalid locale format: " + str); } if (len == 5) { return new Locale(str.substring(0, 2), str.substring(3, 5)); } else { if (str.charAt(5) != '_') { throw new IllegalArgumentException("Invalid locale format: " + str); } return new Locale(str.substring(0, 2), str.substring(3, 5), str.substring(6)); } } } // ----------------------------------------------------------------------- /** *

Obtains the list of locales to search through when performing * a locale search.

* *
     * localeLookupList(Locale("fr","CA","xxx"))
     *   = [Locale("fr","CA","xxx"), Locale("fr","CA"), Locale("fr")]
     * 
* * @param locale the locale to start from * @return the unmodifiable list of Locale objects, 0 being locale, never null */ public static List localeLookupList(Locale locale) { return localeLookupList(locale, locale); } // ----------------------------------------------------------------------- /** *

Obtains the list of locales to search through when performing * a locale search.

* *
     * localeLookupList(Locale("fr", "CA", "xxx"), Locale("en"))
     *   = [Locale("fr","CA","xxx"), Locale("fr","CA"), Locale("fr"), Locale("en"]
     * 
* *

The result list begins with the most specific locale, then the * next more general and so on, finishing with the default locale. * The list will never contain the same locale twice.

* * @param locale the locale to start from, null returns empty list * @param defaultLocale the default locale to use if no other is found * @return the unmodifiable list of Locale objects, 0 being locale, never null */ public static List localeLookupList(Locale locale, Locale defaultLocale) { List list = new ArrayList(4); if (locale != null) { list.add(locale); if (locale.getVariant().length() > 0) { list.add(new Locale(locale.getLanguage(), locale.getCountry())); } if (locale.getCountry().length() > 0) { list.add(new Locale(locale.getLanguage(), "")); } if (list.contains(defaultLocale) == false) { list.add(defaultLocale); } } return Collections.unmodifiableList(list); } // ----------------------------------------------------------------------- /** *

Obtains an unmodifiable list of installed locales.

* *

This method is a wrapper around {@link Locale#getAvailableLocales()}. * It is more efficient, as the JDK method must create a new array each * time it is called.

* * @return the unmodifiable list of available locales */ public static List availableLocaleList() { if (cAvailableLocaleList == null) { initAvailableLocaleList(); } return cAvailableLocaleList; } /** * Initializes the availableLocaleList. It is separate from availableLocaleList() * to avoid the synchronized block affecting normal use, yet synchronized and * lazy loading to avoid a static block affecting other methods in this class. */ private static synchronized void initAvailableLocaleList() { if (cAvailableLocaleList == null) { List list = Arrays.asList(Locale.getAvailableLocales()); cAvailableLocaleList = Collections.unmodifiableList(list); } } // ----------------------------------------------------------------------- /** *

Obtains an unmodifiable set of installed locales.

* *

This method is a wrapper around {@link Locale#getAvailableLocales()}. * It is more efficient, as the JDK method must create a new array each * time it is called.

* * @return the unmodifiable set of available locales */ public static Set availableLocaleSet() { if (cAvailableLocaleSet == null) { initAvailableLocaleSet(); } return cAvailableLocaleSet; } /** * Initializes the availableLocaleSet. It is separate from availableLocaleSet() * to avoid the synchronized block affecting normal use, yet synchronized and * lazy loading to avoid a static block affecting other methods in this class. */ private static synchronized void initAvailableLocaleSet() { if (cAvailableLocaleSet == null) { cAvailableLocaleSet = Collections.unmodifiableSet(new HashSet(availableLocaleList())); } } // ----------------------------------------------------------------------- /** *

Checks if the locale specified is in the list of available locales.

* * @param locale the Locale object to check if it is available * @return true if the locale is a known locale */ public static boolean isAvailableLocale(Locale locale) { return availableLocaleList().contains(locale); } // ----------------------------------------------------------------------- /** *

Obtains the list of languages supported for a given country.

* *

This method takes a country code and searches to find the * languages available for that country. Variant locales are removed.

* * @param countryCode the 2 letter country code, null returns empty * @return an unmodifiable List of Locale objects, never null */ public static List languagesByCountry(String countryCode) { // syncd List langs = (List) cLanguagesByCountry.get(countryCode); if (langs == null) { if (countryCode != null) { langs = new ArrayList(); List locales = availableLocaleList(); for (int i = 0; i < locales.size(); i++) { Locale locale = (Locale) locales.get(i); if (countryCode.equals(locale.getCountry()) && locale.getVariant().length() == 0) { langs.add(locale); } } langs = Collections.unmodifiableList(langs); } else { langs = Collections.EMPTY_LIST; } // syncd cLanguagesByCountry.put(countryCode, langs); } return langs; } // ----------------------------------------------------------------------- /** *

Obtains the list of countries supported for a given language.

* *

This method takes a language code and searches to find the * countries available for that language. Variant locales are removed.

* * @param languageCode the 2 letter language code, null returns empty * @return an unmodifiable List of Locale objects, never null */ public static List countriesByLanguage(String languageCode) { // syncd List countries = (List) cCountriesByLanguage.get(languageCode); if (countries == null) { if (languageCode != null) { countries = new ArrayList(); List locales = availableLocaleList(); for (int i = 0; i < locales.size(); i++) { Locale locale = (Locale) locales.get(i); if (languageCode.equals(locale.getLanguage()) && locale.getCountry().length() != 0 && locale.getVariant().length() == 0) { countries.add(locale); } } countries = Collections.unmodifiableList(countries); } else { countries = Collections.EMPTY_LIST; } // syncd cCountriesByLanguage.put(languageCode, countries); } return countries; } }




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