MessagesManager


1   /**
2    *
3    * Magnolia and its source-code is licensed under the LGPL.
4    * You may copy, adapt, and redistribute this file for commercial or non-commercial use.
5    * When copying, adapting, or redistributing this document in keeping with the guidelines above,
6    * you are required to provide proper attribution to obinary.
7    * If you reproduce or distribute the document without making any substantive modifications to its content,
8    * please use the following attribution line:
9    *
10   * Copyright 1993-2005 obinary Ltd. (http://www.obinary.com) All rights reserved.
11   *
12   */
13  package info.magnolia.cms.i18n;
14  
15  import info.magnolia.cms.beans.config.ContentRepository;
16  import info.magnolia.cms.core.Content;
17  import info.magnolia.cms.core.HierarchyManager;
18  import info.magnolia.cms.core.ItemType;
19  import info.magnolia.cms.core.NodeData;
20  
21  import java.util.ArrayList  ;
22  import java.util.Collection  ;
23  import java.util.Iterator  ;
24  import java.util.Locale  ;
25  
26  import javax.jcr.RepositoryException;
27  import javax.jcr.observation.Event;
28  import javax.jcr.observation.EventIterator;
29  import javax.jcr.observation.EventListener;
30  import javax.jcr.observation.ObservationManager;
31  import javax.servlet.ServletContext  ;
32  import javax.servlet.http.HttpServletRequest  ;
33  import javax.servlet.http.HttpSession  ;
34  import javax.servlet.jsp.PageContext  ;
35  import javax.servlet.jsp.jstl.core.Config;
36  
37  import org.apache.commons.lang.StringUtils;
38  import org.apache.log4j.Logger;
39  
40  
41  /**
42   * From this class you get the i18n messages. You should pass a a request, but if you can't the getMessages method will
43   * handle it properly. The get() methods are easy to use.
44   * @author philipp
45   */
46  public final class MessagesManager {
47  
48      /**
49       * Use this locale if no other provided
50       */
51      public static final String   FALLBACK_LOCALE = "en"; //$NON-NLS-1$
52  
53      /**
54       * Use this basename if no other is provided
55       */
56      public static final String   DEFAULT_BASENAME = "info.magnolia.module.admininterface.messages"; //$NON-NLS-1$
57  
58      /**
59       * Logger.
60       */
61      protected static Logger log = Logger.getLogger(Messages.class);
62  
63      /**
64       * The node name where the configuration for i18n is stored
65       */
66      private static final String   I18N_CONFIG_NAME = "i18n"; //$NON-NLS-1$
67  
68      /**
69       * The name of the property to store the current system language
70       */
71      private static final String   LOCALE_CONFIG_NAME = "language"; //$NON-NLS-1$
72  
73      /**
74       * Under this node all the available languages are stored. They are showed in the user dialog.
75       */
76      private static final String   AVAILABLE_LOCALES_CONFIG_NAME = "availableLanguages"; //$NON-NLS-1$
77  
78      /**
79       * The current locale of the application
80       */
81      private static Locale   applicationLocale;
82  
83      /**
84       * List of the available locales
85       */
86      private static Collection   availableLocales = new ArrayList  ();
87  
88      /**
89       * The context used for the messages
90       */
91      private static ServletContext   context;
92  
93      /**
94       * Util has no public constructor
95       */
96      private MessagesManager() {
97      }
98  
99      /**
100      * Called through the initialization process (startup of the container)
101      * @param context servlet context
102      */
103     public static void init(ServletContext   context) {
104         MessagesManager.context = context;
105 
106         // setting fallback
107         context.setAttribute(Config.FMT_FALLBACK_LOCALE + ".application", FALLBACK_LOCALE); //$NON-NLS-1$
108         // setting basename
109         context.setAttribute(Config.FMT_LOCALIZATION_CONTEXT + ".application", MessagesManager.DEFAULT_BASENAME); //$NON-NLS-1$
110         // for Resin and other J2EE Containers
111         context.setAttribute(Config.FMT_LOCALIZATION_CONTEXT, MessagesManager.DEFAULT_BASENAME);
112 
113         // setting default language (en)
114         MessagesManager.setDefaultLocale(FALLBACK_LOCALE);
115 
116         load();
117         registerEventListener();
118     }
119 
120     /**
121      * Load i18n configuration.
122      */
123     public static void load() {
124 
125         // reading the configuration from the repository
126         HierarchyManager configHierarchyManager = ContentRepository.getHierarchyManager(ContentRepository.CONFIG);
127         try {
128             log.info("Config : loading i18n configuration - " + I18N_CONFIG_NAME); //$NON-NLS-1$
129 
130             Content serverNode = configHierarchyManager.getContent("/server"); //$NON-NLS-1$
131 
132             Content configNode;
133             try {
134                 configNode = serverNode.getContent(I18N_CONFIG_NAME);
135             }
136             catch (javax.jcr.PathNotFoundException e) {
137                 configNode = serverNode.createContent(I18N_CONFIG_NAME, ItemType.CONTENTNODE);
138                 configHierarchyManager.save();
139             }
140 
141             NodeData languageNodeData = configNode.getNodeData(LOCALE_CONFIG_NAME);
142 
143             if (StringUtils.isEmpty(languageNodeData.getName())) {
144                 languageNodeData = configNode.createNodeData(LOCALE_CONFIG_NAME);
145                 languageNodeData.setValue(MessagesManager.FALLBACK_LOCALE);
146                 configHierarchyManager.save();
147             }
148 
149             MessagesManager.setDefaultLocale(languageNodeData.getString());
150 
151             // get the available languages
152             Content availableLanguagesContentNode;
153 
154             NodeData availableLanguage;
155 
156             try {
157                 availableLanguagesContentNode = configNode.getContent(AVAILABLE_LOCALES_CONFIG_NAME);
158             }
159             catch (javax.jcr.PathNotFoundException e) {
160                 availableLanguagesContentNode = configNode.createContent(
161                     AVAILABLE_LOCALES_CONFIG_NAME,
162                     ItemType.CONTENTNODE);
163 
164                 availableLanguage = availableLanguagesContentNode.createNodeData(MessagesManager.FALLBACK_LOCALE);
165                 availableLanguage.setValue(MessagesManager.FALLBACK_LOCALE);
166                 configHierarchyManager.save();
167             }
168 
169             Collection   locales = availableLanguagesContentNode.getNodeDataCollection();
170 
171             // clear collection for reload
172             MessagesManager.availableLocales.clear();
173 
174             for (Iterator   iter = locales.iterator(); iter.hasNext();) {
175                 availableLanguage = (NodeData) iter.next();
176                 String   name = availableLanguage.getString();
177                 String   language = name;
178                 String   country = StringUtils.EMPTY;
179 
180                 if (name.indexOf("_") == 2) { //$NON-NLS-1$
181                     language = name.substring(0, 2);
182                     country = name.substring(3);
183                 }
184                 Locale   locale = new Locale  (language, country);
185                 MessagesManager.availableLocales.add(locale);
186             }
187 
188         }
189         catch (RepositoryException re) {
190             log.error("Config : Failed to load i18n configuration - " + I18N_CONFIG_NAME); //$NON-NLS-1$
191             log.error(re.getMessage(), re);
192         }
193     }
194 
195     /**
196      * Register an event listener: reload configuration when something changes.
197      */
198     private static void registerEventListener() {
199 
200         log.info("Registering event listener for i18n"); //$NON-NLS-1$
201 
202         try {
203             ObservationManager observationManager = ContentRepository
204                 .getHierarchyManager(ContentRepository.CONFIG)
205                 .getWorkspace()
206                 .getObservationManager();
207 
208             observationManager.addEventListener(new EventListener() {
209 
210                 public void onEvent(EventIterator iterator) {
211                     // reload everything
212                     reload();
213                 }
214             }, Event.NODE_ADDED
215                 | Event.NODE_REMOVED
216                 | Event.PROPERTY_ADDED
217                 | Event.PROPERTY_CHANGED
218                 | Event.PROPERTY_REMOVED, "/server/" + I18N_CONFIG_NAME, true, null, null, false); //$NON-NLS-1$
219         }
220         catch (RepositoryException e) {
221             log.error("Unable to add event listeners for i18n", e); //$NON-NLS-1$
222         }
223     }
224 
225     /**
226      * Reload i18n configuration.
227      */
228     public static void reload() {
229         load();
230     }
231 
232     /**
233      * Trys to make a new ContextMessages object. if not possible it creates a new Messages object.
234      * @param req uses the request to find the configuration
235      * @return Messages
236      */
237     public static Messages getMessages(HttpServletRequest   req) {
238         if (req != null) {
239             return new ContextMessages(req);
240         }
241 
242         log.debug("using i18n-messages without a request!"); //$NON-NLS-1$
243         return new Messages(MessagesManager.DEFAULT_BASENAME, applicationLocale);
244 
245     }
246 
247     /**
248      * Provide a basename
249      * @param req request
250      * @param basename basename
251      * @return Messages object to get the messages from
252      */
253     public static Messages getMessages(HttpServletRequest   req, String   basename) {
254         if (req != null) {
255             return new ContextMessages(req, basename);
256         }
257 
258         log.debug("using i18n-messages without a request!"); //$NON-NLS-1$
259         return new Messages(basename, applicationLocale);
260 
261     }
262 
263     /**
264      * Provide a special locale
265      * @param req request
266      * @param basename basename
267      * @param locale locale
268      * @return Messages object to get the messages from
269      */
270     public static Messages getMessages(HttpServletRequest   req, String   basename, Locale   locale) {
271         if (req != null) {
272             return new ContextMessages(req, basename, locale);
273         }
274 
275         log.debug("using i18n-messages without a request!"); //$NON-NLS-1$
276         return new Messages(basename, locale);
277 
278     }
279 
280     /**
281      * Trys to make a new ContextMessages object. if not possible it creates a new Messages object.
282      * @param pc the page context to start the lookup
283      * @return Messages
284      */
285     public static Messages getMessages(PageContext   pc) {
286         if (pc != null && pc.getRequest() instanceof HttpServletRequest  ) {
287             return new ContextMessages((HttpServletRequest  ) pc.getRequest());
288         }
289 
290         log.debug("using i18n-messages without a request inside a control!"); //$NON-NLS-1$
291         return new Messages(MessagesManager.DEFAULT_BASENAME, applicationLocale);
292 
293     }
294 
295     /**
296      * Get a message.
297      * @param req request
298      * @param key key to find
299      * @return message
300      */
301 
302     public static String   get(HttpServletRequest   req, String   key) {
303         return getMessages(req).get(key);
304     }
305 
306     /**
307      * Get a message with parameters inside: the value {0} must be a number
308      * @param req request
309      * @param key key to find
310      * @param args replacement strings
311      * @return message
312      */
313 
314     public static String   get(HttpServletRequest   req, String   key, Object  [] args) {
315         return getMessages(req).get(key, args);
316     }
317 
318     /**
319      * Use a default string.
320      * @param req request
321      * @param key key to find
322      * @param defaultMsg default message
323      * @return message
324      */
325 
326     public static String   getWithDefault(HttpServletRequest   req, String   key, String   defaultMsg) {
327         return getMessages(req).getWithDefault(key, defaultMsg);
328     }
329 
330     /**
331      * Get a message with parameters inside: the value {0} must be a number. Use a default message.
332      * @param req request
333      * @param key key to find
334      * @param args replacement strings
335      * @param defaultMsg default message
336      * @return message
337      */
338     public static String   getWithDefault(HttpServletRequest   req, String   key, Object  [] args, String   defaultMsg) {
339         return getMessages(req).getWithDefault(key, args, defaultMsg);
340     }
341 
342     /**
343      * @return Returns the defaultLocale.
344      */
345     public static Locale   getDefaultLocale() {
346         return applicationLocale;
347     }
348 
349     /**
350      * @return Returns the current locale for the current user
351      */
352     public static Locale   getCurrentLocale(HttpServletRequest   req) {
353         try {
354             return ContextMessages.getCurrentLocale(req);
355         }
356         catch (Exception   e) {
357             return getDefaultLocale();
358         }
359     }
360 
361     /**
362      * @param defaultLocale The defaultLocale to set.
363      */
364     public static void setDefaultLocale(String   defaultLocale) {
365         MessagesManager.applicationLocale = new Locale  (defaultLocale);
366         context.setAttribute(Config.FMT_LOCALE + ".application", defaultLocale); //$NON-NLS-1$
367     }
368 
369     /**
370      * @return Returns the availableLocals.
371      */
372     public static Collection   getAvailableLocales() {
373         return availableLocales;
374     }
375 
376     /**
377      * Set the user language in the session
378      * @param language lagnguage to ste
379      * @param session current session
380      */
381     public static void setUserLanguage(String   language, HttpSession   session) {
382         session.setAttribute(Config.FMT_LOCALE + ".session", language); //$NON-NLS-1$
383     }
384 }
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