001 /*
002 * Copyright (C) 2012 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.ArrayList;
022 import java.util.ServiceConfigurationError;
023 import java.util.ServiceLoader;
024 import java.util.logging.Level;
025 import java.util.logging.Logger;
026
027 public class ServiceLoaderDiscovery implements PluginDiscovery {
028
029 /** . */
030 private static final Logger log = Logger.getLogger(PluginManager.class.getName());
031
032 /** . */
033 private final ClassLoader classLoader;
034
035 /**
036 * Create a new instance.
037 *
038 * @param classLoader the loader for the discovery
039 * @throws NullPointerException if the loader argument is null
040 */
041 public ServiceLoaderDiscovery(ClassLoader classLoader) throws NullPointerException {
042 if (classLoader == null) {
043 throw new NullPointerException();
044 }
045
046 //
047 this.classLoader = classLoader;
048 }
049
050 public Iterable<CRaSHPlugin<?>> getPlugins() {
051
052 //
053 ArrayList<CRaSHPlugin<?>> plugins = new ArrayList<CRaSHPlugin<?>>();
054 try {
055 ServiceLoader<CRaSHPlugin> loader = ServiceLoader.load(CRaSHPlugin.class, classLoader);
056 for (CRaSHPlugin<?> plugin : loader) {
057 log.log(Level.INFO, "Loaded plugin " + plugin);
058 plugins.add(plugin);
059 }
060 }
061 catch (ServiceConfigurationError e) {
062 log.log(Level.SEVERE, "Could not load plugins", e);
063 }
064
065 //
066 return plugins;
067 }
068 }