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 org.slf4j.Logger; 022 import org.slf4j.LoggerFactory; 023 024 import java.util.ArrayList; 025 import java.util.ServiceConfigurationError; 026 import java.util.ServiceLoader; 027 028 /** 029 * An implementation of {@link PluginDiscovery} based on {@link ServiceLoader}. 030 * 031 * @author <a href="mailto:julien.viet@exoplatform.com">Julien Viet</a> 032 */ 033 public class ServiceLoaderDiscovery implements PluginDiscovery { 034 035 /** . */ 036 private static final Logger log = LoggerFactory.getLogger(PluginManager.class); 037 038 /** . */ 039 private final ClassLoader classLoader; 040 041 /** 042 * Create a new instance. 043 * 044 * @param classLoader the loader for the discovery 045 * @throws NullPointerException if the loader argument is null 046 */ 047 public ServiceLoaderDiscovery(ClassLoader classLoader) throws NullPointerException { 048 if (classLoader == null) { 049 throw new NullPointerException(); 050 } 051 052 // 053 this.classLoader = classLoader; 054 } 055 056 public Iterable<CRaSHPlugin<?>> getPlugins() { 057 058 // 059 ArrayList<CRaSHPlugin<?>> plugins = new ArrayList<CRaSHPlugin<?>>(); 060 try { 061 ServiceLoader<CRaSHPlugin> loader = ServiceLoader.load(CRaSHPlugin.class, classLoader); 062 for (CRaSHPlugin<?> plugin : loader) { 063 log.info("Loaded plugin " + plugin); 064 plugins.add(plugin); 065 } 066 } 067 catch (ServiceConfigurationError e) { 068 log.error("Could not load plugins", e); 069 } 070 071 // 072 return plugins; 073 } 074 }