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.vfs.Resource;
023    import org.slf4j.Logger;
024    import org.slf4j.LoggerFactory;
025    
026    import java.io.IOException;
027    import java.io.InputStream;
028    import java.net.URL;
029    import java.util.Properties;
030    
031    /**
032     * Controls the life cycle of a plugin manager.
033     *
034     * @author <a href="mailto:julien.viet@exoplatform.com">Julien Viet</a>
035     * @version $Revision$
036     */
037    public abstract class PluginLifeCycle {
038    
039      /** . */
040      protected final Logger log = LoggerFactory.getLogger(getClass());
041    
042      /** . */
043      private PluginContext context;
044    
045      /** . */
046      private Properties config;
047    
048      public Properties getConfig() {
049        return config;
050      }
051    
052      public void setConfig(Properties config) {
053        this.config = config;
054      }
055    
056      public PluginContext getContext() {
057        return context;
058      }
059    
060      protected final void start(PluginContext context) throws IllegalStateException {
061        if (this.context != null) {
062          throw new IllegalStateException("Already started");
063        }
064        
065        // Get properties from system properties
066        Properties config = new Properties();
067    
068        // Load properties from configuration file
069        Resource res = context.loadResource("crash.properties", ResourceKind.CONFIG);
070        if (res != null) {
071          try {
072            URL url = res.getURL();
073            InputStream in = url.openStream();
074            config.load(in);
075            log.debug("Loaded properties from " + url + " " + config);
076          } catch (IOException e) {
077            log.warn("Could not configure from crash.properties", e);
078          }
079        } else {
080          log.debug("Could not find crash.properties file");
081        }
082    
083        // Override default properties from external config
084        if (this.config != null) {
085          config.putAll(this.config);
086        }
087    
088        // Override default properties from command line
089        for (PropertyDescriptor<?> desc : PropertyDescriptor.ALL.values()) {
090          configureProperty(context, config, desc);
091        }
092    
093        // Override default properties from plugin defined properties.
094        for (final CRaSHPlugin<?> plugin : context.manager.getPlugins())
095        {
096          for (PropertyDescriptor<?> descriptor : plugin.getConfigurationCapabilities()) {
097            configureProperty(context, config, descriptor);
098          }
099        }
100    
101        //
102        context.start();
103    
104        //
105        this.context = context;
106      }
107    
108      public final void stop() throws IllegalStateException {
109        if (context == null) {
110          throw new IllegalStateException("Not started");
111        }
112        PluginContext context = this.context;
113        this.context = null;
114        context.stop();
115      }
116    
117      private void configureProperty(PluginContext context, Properties props, PropertyDescriptor<?> desc) {
118        String key = "crash." + desc.name;
119        String value = props.getProperty(key);
120        if (value != null) {
121          try {
122            log.info("Configuring property " + desc.name + "=" + value + " from properties");
123            context.setProperty(desc, value);
124          }
125          catch (IllegalArgumentException e) {
126            log.error("Could not configure property", e);
127          }
128        }
129      }
130    }