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 */ 019 020 package org.crsh.plugin; 021 022 import org.crsh.util.TypeResolver; 023 import org.slf4j.Logger; 024 import org.slf4j.LoggerFactory; 025 026 import java.util.ArrayList; 027 import java.util.Collections; 028 import java.util.List; 029 030 /** 031 * <p>Base class for a plugin, that consist of a subclass of this class and the implementation 032 * of the business interface of the plugin. The business interface of the plugin is simply 033 * represented by the P generic parameter and its associated class <code>Class<P>></code>.</p> 034 * 035 * @author <a href="mailto:julien.viet@exoplatform.com">Julien Viet</a> 036 * @version $Revision$ 037 * @param <P> the plugin type 038 */ 039 public abstract class CRaSHPlugin<P> { 040 041 /** . */ 042 protected final Logger log = LoggerFactory.getLogger(getClass()); 043 044 /** . */ 045 public static final int FAILED = -1; 046 047 /** . */ 048 public static final int CONSTRUCTED = 0; 049 050 /** . */ 051 public static final int INITIALIZING = 1; 052 053 /** . */ 054 public static final int INITIALIZED = 2; 055 056 /** . */ 057 PluginContext context; 058 059 /** . */ 060 int status; 061 062 /** . */ 063 private final Class<P> type; 064 065 /** . */ 066 private List<PropertyDescriptor<?>> configurationCapabilities; 067 068 protected CRaSHPlugin() { 069 this.type = (Class<P>)TypeResolver.resolveToClass(getClass(), CRaSHPlugin.class, 0); 070 this.status = CONSTRUCTED; 071 this.context = null; 072 } 073 074 protected final PluginContext getContext() { 075 return context; 076 } 077 078 /** 079 * Returns the current plugin status. 080 * 081 * @return the plugin status 082 */ 083 public int getStatus() { 084 return status; 085 } 086 087 /** 088 * Returns the plugin type. 089 * 090 * @return the plugin type 091 */ 092 public final Class<P> getType() { 093 return type; 094 } 095 096 /** 097 * Returns a list of {@link PropertyDescriptor} this plugin requires for its configuration. 098 * 099 * @return the configuration capabilities 100 */ 101 protected Iterable<PropertyDescriptor<?>> createConfigurationCapabilities() { 102 return Collections.emptyList(); 103 } 104 105 /** 106 * Returns a list of {@link PropertyDescriptor} this plugin requires for its configuration. 107 * 108 * @return the configuration capabilities 109 */ 110 public final Iterable<PropertyDescriptor<?>> getConfigurationCapabilities() { 111 if (configurationCapabilities == null) { 112 List<PropertyDescriptor<?>> configurationCapabilities = Collections.emptyList(); 113 for (PropertyDescriptor<?> pd : createConfigurationCapabilities()) { 114 if (configurationCapabilities.isEmpty()) { 115 configurationCapabilities = new ArrayList<PropertyDescriptor<?>>(); 116 } 117 configurationCapabilities.add(pd); 118 } 119 this.configurationCapabilities = configurationCapabilities.isEmpty() ? configurationCapabilities : Collections.unmodifiableList(configurationCapabilities); 120 } 121 return configurationCapabilities; 122 } 123 124 /** 125 * Returns the implementation. 126 * 127 * @return the implementation 128 */ 129 public abstract P getImplementation(); 130 131 /** 132 * Implement this method to know about init life cycle callback. 133 */ 134 public void init() { 135 } 136 137 /** 138 * Implement this method to know about destroy life cycle callback. 139 */ 140 public void destroy() { 141 } 142 143 @Override 144 public String toString() { 145 return "Plugin[type=" + getClass().getSimpleName() + ",interface=" + type.getSimpleName() + "]"; 146 } 147 }