code: /* LanguageTool, a natural language style checker
   * Copyright (C) 2011 Daniel Naber (http://www.danielnaber.de)
   *
   * This library 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 library 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 library; if not, write to the Free Software
   * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301
   * USA
   */
  package org.languagetool;
  
  import java.util.Enumeration;
  import java.util.ResourceBundle;
  
  /**
   * A resource bundle that uses its fallback resource bundle if the
   * value from the original bundle is null or empty.
   */
  public class ResourceBundleWithFallback extends ResourceBundle {
  
    private final ResourceBundle bundle;
    private final ResourceBundle fallbackBundle;
  
    public ResourceBundleWithFallback(ResourceBundle bundle, ResourceBundle fallbackBundle) {
      this.bundle = bundle;
      this.fallbackBundle = fallbackBundle;
    }
  
    @Override
    public Object handleGetObject(String key) {
      String s = bundle.getString(key);
      if (s.trim().isEmpty()) {
        return fallbackBundle.getString(key);
      }
      return s;
    }
  
    @Override
    public Enumeration<String> getKeys() {
      return bundle.getKeys();
    }
  
  }
  