org.gatein.common.i18n.ResourceBundleManager Maven / Gradle / Ivy
The newest version!
/******************************************************************************
* JBoss, a division of Red Hat *
* Copyright 2009, Red Hat Middleware, LLC, and individual *
* contributors as indicated by the @authors tag. See the *
* copyright.txt in the distribution for a full listing of *
* individual contributors. *
* *
* This is free software; you can redistribute it and/or modify it *
* under the terms of the GNU Lesser General Public License as *
* published by the Free Software Foundation; either version 2.1 of *
* the License, or (at your option) any later version. *
* *
* This software is distributed in the hope that it will be useful, *
* but WITHOUT ANY WARRANTY; without even the implied warranty of *
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU *
* Lesser General Public License for more details. *
* *
* You should have received a copy of the GNU Lesser General Public *
* License along with this software; if not, write to the Free *
* Software Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA *
* 02110-1301 USA, or see the FSF site: http://www.fsf.org. *
******************************************************************************/
package org.gatein.common.i18n;
import java.util.HashMap;
import java.util.Locale;
import java.util.Map;
import java.util.MissingResourceException;
import java.util.ResourceBundle;
import java.util.concurrent.ConcurrentMap;
import java.util.concurrent.ConcurrentHashMap;
import org.gatein.common.logging.Logger;
import org.gatein.common.logging.LoggerFactory;
/**
* Manage a set of resource bundles. Obtention of bundles is delegated to a ResourceBundleFactory. A bundle
* obtained successfully is cached in order to avoid the potential expensive cost of the bundle retrieval.
*
* The manager can also be used to build LocalizedString object from the loaded bundles.
*
* @author Julien Viet
* @author Thomas Heute
* @version $Revision: 7228 $
*/
public class ResourceBundleManager
{
/** . */
private final Logger log = LoggerFactory.getLogger(getClass());
/** . */
private final ConcurrentMap localeBundles;
/** . */
private final ResourceBundle defaultBundle;
/** . */
private final ResourceBundleFactory resourceBundleFactory;
/**
* @param defaultBundle the default bundle returned when no bundle has been obtained for the locale
* @param resourceBundleFactory the resource bundle factory
* @throws IllegalArgumentException IllegalArgumentException if the resource bundle factory is null
*/
public ResourceBundleManager(ResourceBundle defaultBundle, ResourceBundleFactory resourceBundleFactory) throws IllegalArgumentException
{
if (resourceBundleFactory == null)
{
throw new IllegalArgumentException("Need a resource bundle factory");
}
this.localeBundles = new ConcurrentHashMap();
this.defaultBundle = defaultBundle;
this.resourceBundleFactory = resourceBundleFactory;
}
/**
* Return a localized value constructed from the various resource bundles. The supported locales of the manager are
* used in combination with the specified key. The default value is used if no value is found for the
* Locale.ENGLISH. Two successive calls to this method may not return identical results since the
* returned LocalizedString is built using the bundles known by the manager.
*
* @param key the key to lookup in the bundles
* @param defaultValue the default value
* @return the localized string
* @throws IllegalArgumentException if the key of the default value is null
*/
public LocalizedString getLocalizedValue(String key, String defaultValue) throws IllegalArgumentException
{
if (key == null)
{
throw new IllegalArgumentException("No null key accepted");
}
if (defaultValue == null)
{
throw new IllegalArgumentException("No null default value accepted");
}
//
Map m = new HashMap();
for (Map.Entry entry : localeBundles.entrySet())
{
try
{
Locale locale = entry.getKey();
ResourceBundle container = entry.getValue().bundle;
//
if (container != null)
{
String localizedDisplayName = container.getString(key);
m.put(locale, localizedDisplayName);
}
}
catch (MissingResourceException ignore)
{
}
}
// Always need default value
if (!m.containsKey(Locale.ENGLISH))
{
m.put(Locale.ENGLISH, defaultValue);
}
//
return new LocalizedString(m, Locale.ENGLISH);
}
/**
* Return a bundle for the given locale. If the complete locale (language + country + variant) does not exist then it
* falls back to (language + country) or (language) or the default file.
*
* When the resource bundle object is found and was not in the global map, it put it in that map with a copy on
* write.
*
* @param locale the locale we want a bundle for
* @return a bundle for the locale or null if not suitable bundle is found.
* @throws IllegalArgumentException if the locale is null
*/
public ResourceBundle getResourceBundle(Locale locale) throws IllegalArgumentException
{
// Arg check
if (locale == null)
{
throw new IllegalArgumentException("Locale cannot be null");
}
// Try to get the bundle if the map
BundleRef ref = localeBundles.get(locale);
if (ref != null)
{
return ref.bundle;
}
//
log.debug("Want to load bundle for locale " + locale);
ResourceBundle bundle = resourceBundleFactory.getBundle(locale);
//
if (bundle != null)
{
log.debug("Obtained bundle " + bundle + " with locale " + bundle.getLocale() + " for locale " + locale);
}
else
{
log.debug("No bundle obtained for locale " + locale + " will use default bundle " + defaultBundle + " instead");
}
// Cache the bundle
localeBundles.put(locale, new BundleRef(bundle));
//
return bundle;
}
/**
* Keeps track of what we loaded, even null.
*/
private static class BundleRef
{
/** . */
final ResourceBundle bundle;
private BundleRef(ResourceBundle bundle)
{
this.bundle = bundle;
}
}
}