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 org.apache.myfaces.application;
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 * Same as toLocale(), but return null when it cannot derive a valid Locale object.
149 *
150 * @param str
151 * @return
152 */
153 public static Locale deriveLocale(String str)
154 {
155 if (str == null)
156 {
157 return null;
158 }
159 int len = str.length();
160 if (len != 2 && len != 5 && len < 7)
161 {
162 return null;
163 }
164 char ch0 = str.charAt(0);
165 char ch1 = str.charAt(1);
166 if (ch0 < 'a' || ch0 > 'z' || ch1 < 'a' || ch1 > 'z')
167 {
168 return null;
169 }
170 if (len == 2)
171 {
172 return new Locale(str, "");
173 }
174 else
175 {
176 if (str.charAt(2) != '_')
177 {
178 return null;
179 }
180 char ch3 = str.charAt(3);
181 if (ch3 == '_')
182 {
183 return new Locale(str.substring(0, 2), "", str.substring(4));
184 }
185 char ch4 = str.charAt(4);
186 if (ch3 < 'A' || ch3 > 'Z' || ch4 < 'A' || ch4 > 'Z')
187 {
188 return null;
189 }
190 if (len == 5)
191 {
192 return new Locale(str.substring(0, 2), str.substring(3, 5));
193 }
194 else
195 {
196 if (str.charAt(5) != '_')
197 {
198 return null;
199 }
200 return new Locale(str.substring(0, 2), str.substring(3, 5), str.substring(6));
201 }
202 }
203 }
204
205 //-----------------------------------------------------------------------
206
207 /**
208 * <p>Obtains the list of locales to search through when performing
209 * a locale search.</p>
210 *
211 * <pre>
212 * localeLookupList(Locale("fr","CA","xxx"))
213 * = [Locale("fr","CA","xxx"), Locale("fr","CA"), Locale("fr")]
214 * </pre>
215 *
216 * @param locale the locale to start from
217 * @return the unmodifiable list of Locale objects, 0 being locale, not null
218 */
219 public static List<Locale> localeLookupList(Locale locale)
220 {
221 return localeLookupList(locale, locale);
222 }
223
224 //-----------------------------------------------------------------------
225
226 /**
227 * <p>Obtains the list of locales to search through when performing
228 * a locale search.</p>
229 *
230 * <pre>
231 * localeLookupList(Locale("fr", "CA", "xxx"), Locale("en"))
232 * = [Locale("fr","CA","xxx"), Locale("fr","CA"), Locale("fr"), Locale("en"]
233 * </pre>
234 *
235 * <p>The result list begins with the most specific locale, then the
236 * next more general and so on, finishing with the default locale.
237 * The list will never contain the same locale twice.</p>
238 *
239 * @param locale the locale to start from, null returns empty list
240 * @param defaultLocale the default locale to use if no other is found
241 * @return the unmodifiable list of Locale objects, 0 being locale, not null
242 */
243 public static List<Locale> localeLookupList(Locale locale, Locale defaultLocale)
244 {
245 List<Locale> list = new ArrayList<Locale>(4);
246 if (locale != null)
247 {
248 list.add(locale);
249 if (locale.getVariant().length() > 0)
250 {
251 list.add(new Locale(locale.getLanguage(), locale.getCountry()));
252 }
253 if (locale.getCountry().length() > 0)
254 {
255 list.add(new Locale(locale.getLanguage(), ""));
256 }
257 if (!list.contains(defaultLocale))
258 {
259 list.add(defaultLocale);
260 }
261 }
262 return Collections.unmodifiableList(list);
263 }
264
265 //-----------------------------------------------------------------------
266
267 /**
268 * <p>Obtains an unmodifiable list of installed locales.</p>
269 *
270 * <p>This method is a wrapper around {@link Locale#getAvailableLocales()}.
271 * It is more efficient, as the JDK method must create a new array each
272 * time it is called.</p>
273 *
274 * @return the unmodifiable list of available locales
275 */
276 public static List<Locale> availableLocaleList()
277 {
278 return SyncAvoid.AVAILABLE_LOCALE_LIST;
279 }
280
281 //-----------------------------------------------------------------------
282
283 /**
284 * <p>Obtains an unmodifiable set of installed locales.</p>
285 *
286 * <p>This method is a wrapper around {@link Locale#getAvailableLocales()}.
287 * It is more efficient, as the JDK method must create a new array each
288 * time it is called.</p>
289 *
290 * @return the unmodifiable set of available locales
291 */
292 public static Set<Locale> availableLocaleSet()
293 {
294 return SyncAvoid.AVAILABLE_LOCALE_SET;
295 }
296
297 //-----------------------------------------------------------------------
298
299 /**
300 * <p>Checks if the locale specified is in the list of available locales.</p>
301 *
302 * @param locale the Locale object to check if it is available
303 * @return true if the locale is a known locale
304 */
305 public static boolean isAvailableLocale(Locale locale)
306 {
307 return availableLocaleList().contains(locale);
308 }
309
310 //-----------------------------------------------------------------------
311
312 /**
313 * <p>Obtains the list of languages supported for a given country.</p>
314 *
315 * <p>This method takes a country code and searches to find the
316 * languages available for that country. Variant locales are removed.</p>
317 *
318 * @param countryCode the 2 letter country code, null returns empty
319 * @return an unmodifiable List of Locale objects, not null
320 */
321 public static List<Locale> languagesByCountry(String countryCode)
322 {
323 if (countryCode == null)
324 {
325 return Collections.emptyList();
326 }
327 List<Locale> langs = LANGUAGES_BY_COUNTRY.get(countryCode);
328 if (langs == null)
329 {
330 langs = new ArrayList<Locale>();
331 List<Locale> locales = availableLocaleList();
332 for (int i = 0; i < locales.size(); i++)
333 {
334 Locale locale = locales.get(i);
335 if (countryCode.equals(locale.getCountry()) &&
336 locale.getVariant().length() == 0)
337 {
338 langs.add(locale);
339 }
340 }
341 langs = Collections.unmodifiableList(langs);
342 LANGUAGES_BY_COUNTRY.putIfAbsent(countryCode, langs);
343 langs = LANGUAGES_BY_COUNTRY.get(countryCode);
344 }
345 return langs;
346 }
347
348 //-----------------------------------------------------------------------
349
350 /**
351 * <p>Obtains the list of countries supported for a given language.</p>
352 *
353 * <p>This method takes a language code and searches to find the
354 * countries available for that language. Variant locales are removed.</p>
355 *
356 * @param languageCode the 2 letter language code, null returns empty
357 * @return an unmodifiable List of Locale objects, not null
358 */
359 public static List<Locale> countriesByLanguage(String languageCode)
360 {
361 if (languageCode == null)
362 {
363 return Collections.emptyList();
364 }
365 List<Locale> countries = COUNTRIES_BY_LANGUAGE.get(languageCode);
366 if (countries == null)
367 {
368 countries = new ArrayList<Locale>();
369 List<Locale> locales = availableLocaleList();
370 for (int i = 0; i < locales.size(); i++)
371 {
372 Locale locale = locales.get(i);
373 if (languageCode.equals(locale.getLanguage()) &&
374 locale.getCountry().length() != 0 &&
375 locale.getVariant().length() == 0)
376 {
377 countries.add(locale);
378 }
379 }
380 countries = Collections.unmodifiableList(countries);
381 COUNTRIES_BY_LANGUAGE.putIfAbsent(languageCode, countries);
382 countries = COUNTRIES_BY_LANGUAGE.get(languageCode);
383 }
384 return countries;
385 }
386
387 //-----------------------------------------------------------------------
388 // class to avoid synchronization
389 static class SyncAvoid
390 {
391 /** Unmodifiable list of available locales. */
392 private static final List<Locale> AVAILABLE_LOCALE_LIST;
393 /** Unmodifiable set of available locales. */
394 private static final Set<Locale> AVAILABLE_LOCALE_SET;
395
396 static
397 {
398 List<Locale> list = new ArrayList<Locale>(Arrays.asList(Locale.getAvailableLocales())); // extra safe
399 AVAILABLE_LOCALE_LIST = Collections.unmodifiableList(list);
400 AVAILABLE_LOCALE_SET = Collections.unmodifiableSet(new HashSet<Locale>(availableLocaleList()));
401 }
402 }
403
404 }