buggy files form Lang #5

projects/Lang/5/org/apache/commons/lang3/LocaleUtils.java

@@ -0,0 +1,301 @@
+/*
+ * 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.lang3;
+
+import java.util.ArrayList;
+import java.util.Arrays;
+import java.util.Collections;
+import java.util.HashSet;
+import java.util.List;
+import java.util.Locale;
+import java.util.Set;
+import java.util.concurrent.ConcurrentHashMap;
+import java.util.concurrent.ConcurrentMap;
+
+/**
+ * <p>Operations to assist when working with a {@link Locale}.</p>
+ *
+ * <p>This class tries to handle {@code null} input gracefully.
+ * An exception will not be thrown for a {@code null} input.
+ * Each method documents its behaviour in more detail.</p>
+ *
+ * @since 2.2
+ * @version $Id$
+ */
+public class LocaleUtils {
+
+    /** Concurrent map of language locales by country. */
+    private static final ConcurrentMap<String, List<Locale>> cLanguagesByCountry = 
+        new ConcurrentHashMap<String, List<Locale>>();
+
+    /** Concurrent map of country locales by language. */
+    private static final ConcurrentMap<String, List<Locale>> cCountriesByLanguage = 
+        new ConcurrentHashMap<String, List<Locale>>();
+
+    /**
+     * <p>{@code LocaleUtils} instances should NOT be constructed in standard programming.
+     * Instead, the class should be used as {@code LocaleUtils.toLocale("en_GB");}.</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(final String str) {
+        if (str == null) {
+            return null;
+        }
+        final int len = str.length();
+        if (len < 2) {
+            throw new IllegalArgumentException("Invalid locale format: " + str);
+        }
+        final char ch0 = str.charAt(0);
+            final char ch1 = str.charAt(1);
+            if (!Character.isLowerCase(ch0) || !Character.isLowerCase(ch1)) {
+                throw new IllegalArgumentException("Invalid locale format: " + str);
+            }
+            if (len == 2) {
+                return new Locale(str);
+            }
+            if (len < 5) {
+                throw new IllegalArgumentException("Invalid locale format: " + str);
+            }
+            if (str.charAt(2) != '_') {
+                throw new IllegalArgumentException("Invalid locale format: " + str);
+            }
+            final char ch3 = str.charAt(3);
+            if (ch3 == '_') {
+                return new Locale(str.substring(0, 2), "", str.substring(4));
+            }
+            final char ch4 = str.charAt(4);
+            if (!Character.isUpperCase(ch3) || !Character.isUpperCase(ch4)) {
+                throw new IllegalArgumentException("Invalid locale format: " + str);
+            }
+            if (len == 5) {
+                return new Locale(str.substring(0, 2), str.substring(3, 5));
+            }
+            if (len < 7) {
+                throw new IllegalArgumentException("Invalid locale format: " + str);
+            }
+            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, not null
+     */
+    public static List<Locale> 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, not null
+     */
+    public static List<Locale> localeLookupList(Locale locale, Locale defaultLocale) {
+        List<Locale> list = new ArrayList<Locale>(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<Locale> availableLocaleList() {
+        return SyncAvoid.AVAILABLE_LOCALE_LIST;
+    }
+
+    //-----------------------------------------------------------------------
+    /**
+     * <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<Locale> availableLocaleSet() {
+        return SyncAvoid.AVAILABLE_LOCALE_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, not null
+     */
+    public static List<Locale> languagesByCountry(String countryCode) {
+        if (countryCode == null) {
+            return Collections.emptyList();
+        }
+        List<Locale> langs = cLanguagesByCountry.get(countryCode);
+        if (langs == null) {
+            langs = new ArrayList<Locale>();
+            List<Locale> locales = availableLocaleList();
+            for (int i = 0; i < locales.size(); i++) {
+                Locale locale = locales.get(i);
+                if (countryCode.equals(locale.getCountry()) &&
+                        locale.getVariant().isEmpty()) {
+                    langs.add(locale);
+                }
+            }
+            langs = Collections.unmodifiableList(langs);
+            cLanguagesByCountry.putIfAbsent(countryCode, langs);
+            langs = cLanguagesByCountry.get(countryCode);
+        }
+        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, not null
+     */
+    public static List<Locale> countriesByLanguage(String languageCode) {
+        if (languageCode == null) {
+            return Collections.emptyList();
+        }
+        List<Locale> countries = cCountriesByLanguage.get(languageCode);
+        if (countries == null) {
+            countries = new ArrayList<Locale>();
+            List<Locale> locales = availableLocaleList();
+            for (int i = 0; i < locales.size(); i++) {
+                Locale locale = locales.get(i);
+                if (languageCode.equals(locale.getLanguage()) &&
+                        locale.getCountry().length() != 0 &&
+                        locale.getVariant().isEmpty()) {
+                    countries.add(locale);
+                }
+            }
+            countries = Collections.unmodifiableList(countries);
+            cCountriesByLanguage.putIfAbsent(languageCode, countries);
+            countries = cCountriesByLanguage.get(languageCode);
+        }
+        return countries;
+    }
+
+    //-----------------------------------------------------------------------
+    // class to avoid synchronization (Init on demand)
+    static class SyncAvoid {
+        /** Unmodifiable list of available locales. */
+        private static final List<Locale> AVAILABLE_LOCALE_LIST;
+        /** Unmodifiable set of available locales. */
+        private static final Set<Locale> AVAILABLE_LOCALE_SET;
+
+        static {
+            List<Locale> list = new ArrayList<Locale>(Arrays.asList(Locale.getAvailableLocales()));  // extra safe
+            AVAILABLE_LOCALE_LIST = Collections.unmodifiableList(list);
+            AVAILABLE_LOCALE_SET = Collections.unmodifiableSet(new HashSet<Locale>(list));
+        }
+    }
+
+}