I18nComponent.java

package org.springframework.roo.addon.web.mvc.i18n.components;

import java.util.Collections;
import java.util.HashSet;
import java.util.Locale;
import java.util.Set;

import org.apache.felix.scr.annotations.Component;
import org.apache.felix.scr.annotations.Reference;
import org.apache.felix.scr.annotations.ReferenceCardinality;
import org.apache.felix.scr.annotations.ReferencePolicy;
import org.apache.felix.scr.annotations.ReferenceStrategy;
import org.apache.felix.scr.annotations.Service;

/**
 * Listener for OSGi service events for registering and unregistering I18n
 * addons.
 * 
 * @author Stefan Schmidt
 * @since 1.1
 */
@Component
@Service
@Reference(name = "language", strategy = ReferenceStrategy.EVENT, policy = ReferencePolicy.DYNAMIC,
    referenceInterface = I18n.class, cardinality = ReferenceCardinality.OPTIONAL_MULTIPLE)
public class I18nComponent implements I18nSupport {

  private final Set<I18n> i18nSet = new HashSet<I18n>();
  private final Object mutex = new Object();

  protected void bindLanguage(final I18n i18n) {
    synchronized (mutex) {
      i18nSet.add(i18n);
    }
  }

  public I18n getLanguage(final Locale locale) {
    synchronized (mutex) {
      for (final I18n lang : Collections.unmodifiableSet(i18nSet)) {
        if (lang.getLocale().toString().equalsIgnoreCase(locale.toString())) {
          return lang;
        }
      }
    }
    return null;
  }

  public Set<I18n> getSupportedLanguages() {
    Set<I18n> set = null;
    synchronized (mutex) {
      set = Collections.unmodifiableSet(i18nSet);
    }
    return set;
  }

  protected void unbindLanguage(final I18n i18n) {
    synchronized (mutex) {
      i18nSet.remove(i18n);
    }
  }
}