1 /**
2 * Copyright (C) 2005-2009 Alfresco Software Limited.
3 *
4 * This file is part of the Spring Surf Extension project.
5 *
6 * Licensed under the Apache License, Version 2.0 (the "License");
7 * you may not use this file except in compliance with the License.
8 * 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, software
13 * distributed under the License is distributed on an "AS IS" BASIS,
14 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
15 * See the License for the specific language governing permissions and
16 * limitations under the License.
17 */
18
19 package org.springframework.extensions.surf.util;
20
21 import java.text.MessageFormat;
22 import java.util.Enumeration;
23 import java.util.HashMap;
24 import java.util.HashSet;
25 import java.util.Iterator;
26 import java.util.Locale;
27 import java.util.Map;
28 import java.util.ResourceBundle;
29 import java.util.Set;
30 import java.util.StringTokenizer;
31 import java.util.concurrent.locks.Lock;
32 import java.util.concurrent.locks.ReadWriteLock;
33 import java.util.concurrent.locks.ReentrantReadWriteLock;
34
35 /**
36 * Utility class providing methods to access the Locale of the current thread and to get
37 * Localised strings.
38 *
39 * @author Roy Wetherall
40 */
41 public class I18NUtil
42 {
43 /**
44 * Thread-local containing the general Locale for the current thread
45 */
46 private static ThreadLocal<Locale> threadLocale = new ThreadLocal<Locale>();
47
48 /**
49 * Thread-local containing the content Locale for for the current thread. This
50 * can be used for content and property filtering.
51 */
52 private static ThreadLocal<Locale> threadContentLocale = new ThreadLocal<Locale>();
53
54 /**
55 * List of registered bundles
56 */
57 private static Set<String> resouceBundleBaseNames = new HashSet<String>();
58
59 /**
60 * Map of loaded bundles by Locale
61 */
62 private static Map<Locale, Set<String>> loadedResourceBundles = new HashMap<Locale, Set<String>>();
63
64 /**
65 * Map of cached messaged by Locale
66 */
67 private static Map<Locale, Map<String, String>> cachedMessages = new HashMap<Locale, Map<String, String>>();
68
69 /**
70 * Lock objects
71 */
72 private static ReadWriteLock lock = new ReentrantReadWriteLock();
73 private static Lock readLock = lock.readLock();
74 private static Lock writeLock = lock.writeLock();
75
76 /**
77 * Set the locale for the current thread.
78 *
79 * @param locale the locale
80 */
81 public static void setLocale(Locale locale)
82 {
83 threadLocale.set(locale);
84 }
85
86 /**
87 * Get the general local for the current thread, will revert to the default locale if none
88 * specified for this thread.
89 *
90 * @return the general locale
91 */
92 public static Locale getLocale()
93 {
94 Locale locale = threadLocale.get();
95 if (locale == null)
96 {
97 // Get the default locale
98 locale = Locale.getDefault();
99 }
100 return locale;
101 }
102
103 /**
104 * Set the <b>content locale</b> for the current thread.
105 *
106 * @param locale the content locale
107 */
108 public static void setContentLocale(Locale locale)
109 {
110 threadContentLocale.set(locale);
111 }
112
113 /**
114 * Get the content local for the current thread.<br/>
115 * This will revert to {@link #getLocale()} if no value has been defined.
116 *
117 * @return Returns the content locale
118 */
119 public static Locale getContentLocale()
120 {
121 Locale locale = threadContentLocale.get();
122 if (locale == null)
123 {
124 // Revert to the normal locale
125 locale = getLocale();
126 }
127 return locale;
128 }
129
130 /**
131 * Get the content local for the current thread.<br/>
132 * This will revert <tt>null</tt> if no value has been defined.
133 *
134 * @return Returns the content locale
135 */
136 public static Locale getContentLocaleOrNull()
137 {
138 Locale locale = threadContentLocale.get();
139
140 return locale;
141 }
142
143
144 /**
145 * Searches for the nearest locale from the available options. To match any locale, pass in
146 * <tt>null</tt>.
147 *
148 * @param templateLocale the template to search for or <tt>null</tt> to match any locale
149 * @param options the available locales to search from
150 * @return Returns the best match from the available options, or the <tt>null</tt> if
151 * all matches fail
152 */
153 public static Locale getNearestLocale(Locale templateLocale, Set<Locale> options)
154 {
155 if (options.isEmpty()) // No point if there are no options
156 {
157 return null;
158 }
159 else if (templateLocale == null)
160 {
161 for (Locale locale : options)
162 {
163 return locale;
164 }
165 }
166 else if (options.contains(templateLocale)) // First see if there is an exact match
167 {
168 return templateLocale;
169 }
170 // make a copy of the set
171 Set<Locale> remaining = new HashSet<Locale>(options);
172
173 // eliminate those without matching languages
174 Locale lastMatchingOption = null;
175 String templateLanguage = templateLocale.getLanguage();
176 if (templateLanguage != null && !templateLanguage.equals(""))
177 {
178 Iterator<Locale> iterator = remaining.iterator();
179 while (iterator.hasNext())
180 {
181 Locale option = iterator.next();
182 if (option != null && !templateLanguage.equals(option.getLanguage()))
183 {
184 iterator.remove(); // It doesn't match, so remove
185 }
186 else
187 {
188 lastMatchingOption = option; // Keep a record of the last match
189 }
190 }
191 }
192 if (remaining.isEmpty())
193 {
194 return null;
195 }
196 else if (remaining.size() == 1 && lastMatchingOption != null)
197 {
198 return lastMatchingOption;
199 }
200
201 // eliminate those without matching country codes
202 lastMatchingOption = null;
203 String templateCountry = templateLocale.getCountry();
204 if (templateCountry != null && !templateCountry.equals(""))
205 {
206 Iterator<Locale> iterator = remaining.iterator();
207 while (iterator.hasNext())
208 {
209 Locale option = iterator.next();
210 if (option != null && !templateCountry.equals(option.getCountry()))
211 {
212 // It doesn't match language - remove
213 // Don't remove the iterator. If it matchs a langage but not the country, returns any matched language
214 // iterator.remove();
215 }
216 else
217 {
218 lastMatchingOption = option; // Keep a record of the last match
219 }
220 }
221 }
222 /*if (remaining.isEmpty())
223 {
224 return null;
225 }
226 else */
227 if (remaining.size() == 1 && lastMatchingOption != null)
228 {
229 return lastMatchingOption;
230 }
231 else
232 {
233 // We have done an earlier equality check, so there isn't a matching variant
234 // Also, we know that there are multiple options at this point, either of which will do.
235
236 // This gets any country match (there will be worse matches so we take the last the country match)
237 if(lastMatchingOption != null)
238 {
239 return lastMatchingOption;
240 }
241 else
242 {
243 for (Locale locale : remaining)
244 {
245 return locale;
246 }
247 }
248 }
249 // The logic guarantees that this code can't be called
250 throw new RuntimeException("Logic should not allow code to get here.");
251 }
252
253 /**
254 * Factory method to create a Locale from a <tt>lang_country_variant</tt> string.
255 *
256 * @param localeStr e.g. fr_FR
257 * @return Returns the locale instance, or the {@link Locale#getDefault() default} if the
258 * string is invalid
259 */
260 public static Locale parseLocale(String localeStr)
261 {
262 if(localeStr == null)
263 {
264 return null;
265 }
266 Locale locale = Locale.getDefault();
267
268 StringTokenizer t = new StringTokenizer(localeStr, "_");
269 int tokens = t.countTokens();
270 if (tokens == 1)
271 {
272 locale = new Locale(t.nextToken());
273 }
274 else if (tokens == 2)
275 {
276 locale = new Locale(t.nextToken(), t.nextToken());
277 }
278 else if (tokens == 3)
279 {
280 locale = new Locale(t.nextToken(), t.nextToken(), t.nextToken());
281 }
282
283 return locale;
284 }
285
286 /**
287 * Register a resource bundle.
288 * <p>
289 * This should be the bundle base name eg, spring-surf.messages.errors
290 * <p>
291 * Once registered the messges will be available via getMessage
292 *
293 * @param bundleBaseName the bundle base name
294 */
295 public static void registerResourceBundle(String bundleBaseName)
296 {
297 try
298 {
299 writeLock.lock();
300 resouceBundleBaseNames.add(bundleBaseName);
301 }
302 finally
303 {
304 writeLock.unlock();
305 }
306 }
307
308 /**
309 * Get message from registered resource bundle.
310 *
311 * @param messageKey message key
312 * @return localised message string, null if not found
313 */
314 public static String getMessage(String messageKey)
315 {
316 return getMessage(messageKey, getLocale());
317 }
318
319 /**
320 * Get a localised message string
321 *
322 * @param messageKey the message key
323 * @param locale override the current locale
324 * @return the localised message string, null if not found
325 */
326 public static String getMessage(String messageKey, Locale locale)
327 {
328 String message = null;
329 Map<String, String> props = getLocaleProperties(locale);
330 if (props != null)
331 {
332 message = props.get(messageKey);
333 }
334 return message;
335 }
336
337 /**
338 * Get a localised message string, parameterized using standard MessageFormatter.
339 *
340 * @param messageKey message key
341 * @param params format parameters
342 * @return the localised string, null if not found
343 */
344 public static String getMessage(String messageKey, Object ... params)
345 {
346 return getMessage(messageKey, getLocale(), params);
347 }
348
349 /**
350 * Get a localised message string, parameterized using standard MessageFormatter.
351 *
352 * @param messageKey the message key
353 * @param locale override current locale
354 * @param params the localised message string
355 * @return the localaised string, null if not found
356 */
357 public static String getMessage(String messageKey, Locale locale, Object ... params)
358 {
359 String message = getMessage(messageKey, locale);
360 if (message != null && params != null)
361 {
362 message = MessageFormat.format(message, params);
363 }
364 return message;
365 }
366
367 /**
368 * @return the map of all available messages for the current locale
369 */
370 public static Map<String, String> getAllMessages()
371 {
372 return getLocaleProperties(getLocale());
373 }
374
375 /**
376 * @return the map of all available messages for the specified locale
377 */
378 public static Map<String, String> getAllMessages(Locale locale)
379 {
380 return getLocaleProperties(locale);
381 }
382
383 /**
384 * Get the messages for a locale.
385 * <p>
386 * Will use cache where available otherwise will load into cache from bundles.
387 *
388 * @param locale the locale
389 * @return message map
390 */
391 private static Map<String, String> getLocaleProperties(Locale locale)
392 {
393 Set<String> loadedBundles = null;
394 Map<String, String> props = null;
395 int loadedBundleCount = 0;
396 try
397 {
398 readLock.lock();
399 loadedBundles = loadedResourceBundles.get(locale);
400 props = cachedMessages.get(locale);
401 loadedBundleCount = resouceBundleBaseNames.size();
402 }
403 finally
404 {
405 readLock.unlock();
406 }
407
408 if (loadedBundles == null)
409 {
410 try
411 {
412 writeLock.lock();
413 loadedBundles = new HashSet<String>();
414 loadedResourceBundles.put(locale, loadedBundles);
415 }
416 finally
417 {
418 writeLock.unlock();
419 }
420 }
421
422 if (props == null)
423 {
424 try
425 {
426 writeLock.lock();
427 props = new HashMap<String, String>();
428 cachedMessages.put(locale, props);
429 }
430 finally
431 {
432 writeLock.unlock();
433 }
434 }
435
436 if (loadedBundles.size() != loadedBundleCount)
437 {
438 try
439 {
440 writeLock.lock();
441 for (String resourceBundleBaseName : resouceBundleBaseNames)
442 {
443 if (loadedBundles.contains(resourceBundleBaseName) == false)
444 {
445 ResourceBundle resourcebundle = ResourceBundle.getBundle(resourceBundleBaseName, locale);
446 Enumeration<String> enumKeys = resourcebundle.getKeys();
447 while (enumKeys.hasMoreElements() == true)
448 {
449 String key = enumKeys.nextElement();
450 props.put(key, resourcebundle.getString(key));
451 }
452 loadedBundles.add(resourceBundleBaseName);
453 }
454 }
455 }
456 finally
457 {
458 writeLock.unlock();
459 }
460 }
461
462 return props;
463 }
464 }