1 /*
2 * Licensed to the Apache Software Foundation (ASF) under one
3 * or more contributor license agreements. See the NOTICE file
4 * distributed with this work for additional information
5 * regarding copyright ownership. The ASF licenses this file
6 * to you under the Apache License, Version 2.0 (the
7 * "License"); you may not use this file except in compliance
8 * with the License. You may obtain a copy of the License at
9 *
10 * http://www.apache.org/licenses/LICENSE-2.0
11 *
12 * Unless required by applicable law or agreed to in writing,
13 * software distributed under the License is distributed on an
14 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
15 * KIND, either express or implied. See the License for the
16 * specific language governing permissions and limitations
17 * under the License.
18 */
19 package javax.faces.component;
20
21 import java.util.ArrayList;
22 import java.util.Arrays;
23 import java.util.Collections;
24 import java.util.HashSet;
25 import java.util.List;
26 import java.util.Locale;
27 import java.util.Set;
28 import java.util.concurrent.ConcurrentHashMap;
29 import java.util.concurrent.ConcurrentMap;
30
31 /**
32 * <p>Operations to assist when working with a {@link Locale}.</p>
33 *
34 * <p>This class tries to handle {@code null} input gracefully.
35 * An exception will not be thrown for a {@code null} input.
36 * Each method documents its behaviour in more detail.</p>
37 *
38 * NOTE: This a copy of commons lang LocaleUtils, to use it inside MyFaces
39 *
40 * @since 2.2
41 * @version $Id$
42 */
43 class _LocaleUtils
44 {
45
46 /** Concurrent map of language locales by country. */
47 private static final ConcurrentMap<String, List<Locale>> LANGUAGES_BY_COUNTRY =
48 new ConcurrentHashMap<String, List<Locale>>();
49
50 /** Concurrent map of country locales by language. */
51 private static final ConcurrentMap<String, List<Locale>> COUNTRIES_BY_LANGUAGE =
52 new ConcurrentHashMap<String, List<Locale>>();
53
54 /**
55 * <p>{@code _LocaleUtils} instances should NOT be constructed in standard programming.
56 * Instead, the class should be used as {@code _LocaleUtils.toLocale("en_GB");}.</p>
57 *
58 * <p>This constructor is public to permit tools that require a JavaBean instance
59 * to operate.</p>
60 */
61 public _LocaleUtils()
62 {
63 super();
64 }
65
66 //-----------------------------------------------------------------------
67
68 /**
69 * <p>Converts a String to a Locale.</p>
70 *
71 * <p>This method takes the string format of a locale and creates the
72 * locale object from it.</p>
73 *
74 * <pre>
75 * _LocaleUtils.toLocale("en") = new Locale("en", "")
76 * _LocaleUtils.toLocale("en_GB") = new Locale("en", "GB")
77 * _LocaleUtils.toLocale("en_GB_xxx") = new Locale("en", "GB", "xxx") (#)
78 * </pre>
79 *
80 * <p>(#) The behaviour of the JDK variant constructor changed between JDK1.3 and JDK1.4.
81 * In JDK1.3, the constructor upper cases the variant, in JDK1.4, it doesn't.
82 * Thus, the result from getVariant() may vary depending on your JDK.</p>
83 *
84 * <p>This method validates the input strictly.
85 * The language code must be lowercase.
86 * The country code must be uppercase.
87 * The separator must be an underscore.
88 * The length must be correct.
89 * </p>
90 *
91 * @param str the locale String to convert, null returns null
92 * @return a Locale, null if null input
93 * @throws IllegalArgumentException if the string is an invalid format
94 */
95 public static Locale toLocale(String str)
96 {
97 if (str == null)
98 {
99 return null;
100 }
101 int len = str.length();
102 if (len != 2 && len != 5 && len < 7)
103 {
104 throw new IllegalArgumentException("Invalid locale format: " + str);
105 }
106 char ch0 = str.charAt(0);
107 char ch1 = str.charAt(1);
108 if (ch0 < 'a' || ch0 > 'z' || ch1 < 'a' || ch1 > 'z')
109 {
110 throw new IllegalArgumentException("Invalid locale format: " + str);
111 }
112 if (len == 2)
113 {
114 return new Locale(str, "");
115 }
116 else
117 {
118 if (str.charAt(2) != '_')
119 {
120 throw new IllegalArgumentException("Invalid locale format: " + str);
121 }
122 char ch3 = str.charAt(3);
123 if (ch3 == '_')
124 {
125 return new Locale(str.substring(0, 2), "", str.substring(4));
126 }
127 char ch4 = str.charAt(4);
128 if (ch3 < 'A' || ch3 > 'Z' || ch4 < 'A' || ch4 > 'Z')
129 {
130 throw new IllegalArgumentException("Invalid locale format: " + str);
131 }
132 if (len == 5)
133 {
134 return new Locale(str.substring(0, 2), str.substring(3, 5));
135 }
136 else
137 {
138 if (str.charAt(5) != '_')
139 {
140 throw new IllegalArgumentException("Invalid locale format: " + str);
141 }
142 return new Locale(str.substring(0, 2), str.substring(3, 5), str.substring(6));
143 }
144 }
145 }
146
147 //-----------------------------------------------------------------------
148
149 /**
150 * <p>Obtains the list of locales to search through when performing
151 * a locale search.</p>
152 *
153 * <pre>
154 * localeLookupList(Locale("fr","CA","xxx"))
155 * = [Locale("fr","CA","xxx"), Locale("fr","CA"), Locale("fr")]
156 * </pre>
157 *
158 * @param locale the locale to start from
159 * @return the unmodifiable list of Locale objects, 0 being locale, not null
160 */
161 public static List<Locale> localeLookupList(Locale locale)
162 {
163 return localeLookupList(locale, locale);
164 }
165
166 //-----------------------------------------------------------------------
167
168 /**
169 * <p>Obtains the list of locales to search through when performing
170 * a locale search.</p>
171 *
172 * <pre>
173 * localeLookupList(Locale("fr", "CA", "xxx"), Locale("en"))
174 * = [Locale("fr","CA","xxx"), Locale("fr","CA"), Locale("fr"), Locale("en"]
175 * </pre>
176 *
177 * <p>The result list begins with the most specific locale, then the
178 * next more general and so on, finishing with the default locale.
179 * The list will never contain the same locale twice.</p>
180 *
181 * @param locale the locale to start from, null returns empty list
182 * @param defaultLocale the default locale to use if no other is found
183 * @return the unmodifiable list of Locale objects, 0 being locale, not null
184 */
185 public static List<Locale> localeLookupList(Locale locale, Locale defaultLocale)
186 {
187 List<Locale> list = new ArrayList<Locale>(4);
188 if (locale != null)
189 {
190 list.add(locale);
191 if (locale.getVariant().length() > 0)
192 {
193 list.add(new Locale(locale.getLanguage(), locale.getCountry()));
194 }
195 if (locale.getCountry().length() > 0)
196 {
197 list.add(new Locale(locale.getLanguage(), ""));
198 }
199 if (!list.contains(defaultLocale))
200 {
201 list.add(defaultLocale);
202 }
203 }
204 return Collections.unmodifiableList(list);
205 }
206
207 //-----------------------------------------------------------------------
208
209 /**
210 * <p>Obtains an unmodifiable list of installed locales.</p>
211 *
212 * <p>This method is a wrapper around {@link Locale#getAvailableLocales()}.
213 * It is more efficient, as the JDK method must create a new array each
214 * time it is called.</p>
215 *
216 * @return the unmodifiable list of available locales
217 */
218 public static List<Locale> availableLocaleList()
219 {
220 return SyncAvoid.AVAILABLE_LOCALE_LIST;
221 }
222
223 //-----------------------------------------------------------------------
224
225 /**
226 * <p>Obtains an unmodifiable set of installed locales.</p>
227 *
228 * <p>This method is a wrapper around {@link Locale#getAvailableLocales()}.
229 * It is more efficient, as the JDK method must create a new array each
230 * time it is called.</p>
231 *
232 * @return the unmodifiable set of available locales
233 */
234 public static Set<Locale> availableLocaleSet()
235 {
236 return SyncAvoid.AVAILABLE_LOCALE_SET;
237 }
238
239 //-----------------------------------------------------------------------
240
241 /**
242 * <p>Checks if the locale specified is in the list of available locales.</p>
243 *
244 * @param locale the Locale object to check if it is available
245 * @return true if the locale is a known locale
246 */
247 public static boolean isAvailableLocale(Locale locale)
248 {
249 return availableLocaleList().contains(locale);
250 }
251
252 //-----------------------------------------------------------------------
253
254 /**
255 * <p>Obtains the list of languages supported for a given country.</p>
256 *
257 * <p>This method takes a country code and searches to find the
258 * languages available for that country. Variant locales are removed.</p>
259 *
260 * @param countryCode the 2 letter country code, null returns empty
261 * @return an unmodifiable List of Locale objects, not null
262 */
263 public static List<Locale> languagesByCountry(String countryCode)
264 {
265 if (countryCode == null)
266 {
267 return Collections.emptyList();
268 }
269 List<Locale> langs = LANGUAGES_BY_COUNTRY.get(countryCode);
270 if (langs == null)
271 {
272 langs = new ArrayList<Locale>();
273 List<Locale> locales = availableLocaleList();
274 for (int i = 0; i < locales.size(); i++)
275 {
276 Locale locale = locales.get(i);
277 if (countryCode.equals(locale.getCountry()) &&
278 locale.getVariant().length() == 0)
279 {
280 langs.add(locale);
281 }
282 }
283 langs = Collections.unmodifiableList(langs);
284 LANGUAGES_BY_COUNTRY.putIfAbsent(countryCode, langs);
285 langs = LANGUAGES_BY_COUNTRY.get(countryCode);
286 }
287 return langs;
288 }
289
290 //-----------------------------------------------------------------------
291
292 /**
293 * <p>Obtains the list of countries supported for a given language.</p>
294 *
295 * <p>This method takes a language code and searches to find the
296 * countries available for that language. Variant locales are removed.</p>
297 *
298 * @param languageCode the 2 letter language code, null returns empty
299 * @return an unmodifiable List of Locale objects, not null
300 */
301 public static List<Locale> countriesByLanguage(String languageCode)
302 {
303 if (languageCode == null)
304 {
305 return Collections.emptyList();
306 }
307 List<Locale> countries = COUNTRIES_BY_LANGUAGE.get(languageCode);
308 if (countries == null)
309 {
310 countries = new ArrayList<Locale>();
311 List<Locale> locales = availableLocaleList();
312 for (int i = 0; i < locales.size(); i++)
313 {
314 Locale locale = locales.get(i);
315 if (languageCode.equals(locale.getLanguage()) &&
316 locale.getCountry().length() != 0 &&
317 locale.getVariant().length() == 0)
318 {
319 countries.add(locale);
320 }
321 }
322 countries = Collections.unmodifiableList(countries);
323 COUNTRIES_BY_LANGUAGE.putIfAbsent(languageCode, countries);
324 countries = COUNTRIES_BY_LANGUAGE.get(languageCode);
325 }
326 return countries;
327 }
328
329 //-----------------------------------------------------------------------
330 // class to avoid synchronization
331 static class SyncAvoid
332 {
333 /** Unmodifiable list of available locales. */
334 private static final List<Locale> AVAILABLE_LOCALE_LIST;
335 /** Unmodifiable set of available locales. */
336 private static final Set<Locale> AVAILABLE_LOCALE_SET;
337
338 static
339 {
340 List<Locale> list = new ArrayList<Locale>(Arrays.asList(Locale.getAvailableLocales())); // extra safe
341 AVAILABLE_LOCALE_LIST = Collections.unmodifiableList(list);
342 AVAILABLE_LOCALE_SET = Collections.unmodifiableSet(new HashSet<Locale>(availableLocaleList()));
343 }
344 }
345
346 }