001    /*
002     * Copyright (C) 2010 eXo Platform SAS.
003     *
004     * This is free software; you can redistribute it and/or modify it
005     * under the terms of the GNU Lesser General Public License as
006     * published by the Free Software Foundation; either version 2.1 of
007     * the License, or (at your option) any later version.
008     *
009     * This software is distributed in the hope that it will be useful,
010     * but WITHOUT ANY WARRANTY; without even the implied warranty of
011     * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
012     * Lesser General Public License for more details.
013     *
014     * You should have received a copy of the GNU Lesser General Public
015     * License along with this software; if not, write to the Free
016     * Software Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
017     * 02110-1301 USA, or see the FSF site: http://www.fsf.org.
018     */
019    package org.crsh.plugin;
020    
021    import java.util.Collections;
022    import java.util.LinkedHashSet;
023    
024    /**
025     * @author <a href="mailto:julien.viet@exoplatform.com">Julien Viet</a>
026     */
027    public class SimplePluginDiscovery implements PluginDiscovery {
028    
029      private final LinkedHashSet<CRaSHPlugin<?>> plugins;
030    
031      public SimplePluginDiscovery() {
032        this.plugins = new LinkedHashSet<CRaSHPlugin<?>>();
033      }
034    
035      /**
036       * Add a plugin.
037       *
038       * @param plugin the plugin
039       * @return this object
040       * @throws NullPointerException if the plugin is null
041       */
042      public SimplePluginDiscovery add(CRaSHPlugin<?> plugin) throws NullPointerException {
043        if (plugin == null) {
044          throw new NullPointerException();
045        }
046        plugins.add(plugin);
047        return this;
048      }
049    
050      public Iterable<CRaSHPlugin<?>> getPlugins() {
051        return Collections.unmodifiableSet(plugins);
052      }
053    }