| /* |
| * 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.lang2; |
| |
| 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; |
| |
| /** |
| * <p>Operations to assist when working with a {@link Locale}.</p> |
| * |
| * <p>This class tries to handle <code>null</code> input gracefully. |
| * An exception will not be thrown for a <code>null</code> input. |
| * Each method documents its behaviour in more detail.</p> |
| * |
| * @author Stephen Colebourne |
| * @since 2.2 |
| * @version $Id$ |
| */ |
| public class LocaleUtils { |
| |
| /** Unmodifiable list of available locales. */ |
| private static final List cAvailableLocaleList; |
| /** Unmodifiable set of available locales. */ |
| 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()); |
| static { |
| List list = Arrays.asList(Locale.getAvailableLocales()); |
| cAvailableLocaleList = Collections.unmodifiableList(list); |
| } |
| |
| /** |
| * <p><code>LocaleUtils</code> instances should NOT be constructed in standard programming. |
| * Instead, the class should be used as <code>LocaleUtils.toLocale("en_GB");</code>.</p> |
| * |
| * <p>This constructor is public to permit tools that require a JavaBean instance |
| * to operate.</p> |
| */ |
| public LocaleUtils() { |
| super(); |
| } |
| |
| //----------------------------------------------------------------------- |
| /** |
| * <p>Converts a String to a Locale.</p> |
| * |
| * <p>This method takes the string format of a locale and creates the |
| * locale object from it.</p> |
| * |
| * <pre> |
| * LocaleUtils.toLocale("en") = new Locale("en", "") |
| * LocaleUtils.toLocale("en_GB") = new Locale("en", "GB") |
| * LocaleUtils.toLocale("en_GB_xxx") = new Locale("en", "GB", "xxx") (#) |
| * </pre> |
| * |
| * <p>(#) 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.</p> |
| * |
| * <p>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. |
| * </p> |
| * |
| * @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); |
| 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)); |
| } |
| } |
| } |
| |
| //----------------------------------------------------------------------- |
| /** |
| * <p>Obtains the list of locales to search through when performing |
| * a locale search.</p> |
| * |
| * <pre> |
| * localeLookupList(Locale("fr","CA","xxx")) |
| * = [Locale("fr","CA","xxx"), Locale("fr","CA"), Locale("fr")] |
| * </pre> |
| * |
| * @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); |
| } |
| |
| //----------------------------------------------------------------------- |
| /** |
| * <p>Obtains the list of locales to search through when performing |
| * a locale search.</p> |
| * |
| * <pre> |
| * localeLookupList(Locale("fr", "CA", "xxx"), Locale("en")) |
| * = [Locale("fr","CA","xxx"), Locale("fr","CA"), Locale("fr"), Locale("en"] |
| * </pre> |
| * |
| * <p>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.</p> |
| * |
| * @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); |
| } |
| |
| //----------------------------------------------------------------------- |
| /** |
| * <p>Obtains an unmodifiable list of installed locales.</p> |
| * |
| * <p>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.</p> |
| * |
| * @return the unmodifiable list of available locales |
| */ |
| public static List availableLocaleList() { |
| return cAvailableLocaleList; |
| } |
| |
| //----------------------------------------------------------------------- |
| /** |
| * <p>Obtains an unmodifiable set of installed locales.</p> |
| * |
| * <p>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.</p> |
| * |
| * @return the unmodifiable set of available locales |
| */ |
| public static Set availableLocaleSet() { |
| Set set = cAvailableLocaleSet; |
| if (set == null) { |
| set = new HashSet(availableLocaleList()); |
| set = Collections.unmodifiableSet(set); |
| cAvailableLocaleSet = set; |
| } |
| return set; |
| } |
| |
| //----------------------------------------------------------------------- |
| /** |
| * <p>Checks if the locale specified is in the list of available locales.</p> |
| * |
| * @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); |
| } |
| |
| //----------------------------------------------------------------------- |
| /** |
| * <p>Obtains the list of languages supported for a given country.</p> |
| * |
| * <p>This method takes a country code and searches to find the |
| * languages available for that country. Variant locales are removed.</p> |
| * |
| * @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) { |
| List langs = (List) cLanguagesByCountry.get(countryCode); //syncd |
| 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; |
| } |
| cLanguagesByCountry.put(countryCode, langs); //syncd |
| } |
| return langs; |
| } |
| |
| //----------------------------------------------------------------------- |
| /** |
| * <p>Obtains the list of countries supported for a given language.</p> |
| * |
| * <p>This method takes a language code and searches to find the |
| * countries available for that language. Variant locales are removed.</p> |
| * |
| * @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) { |
| List countries = (List) cCountriesByLanguage.get(languageCode); //syncd |
| 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; |
| } |
| cCountriesByLanguage.put(languageCode, countries); //syncd |
| } |
| return countries; |
| } |
| |
| } |
