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    
020    package org.crsh.plugin;
021    
022    import org.crsh.vfs.Resource;
023    
024    import java.io.ByteArrayInputStream;
025    import java.io.IOException;
026    import java.util.Properties;
027    import java.util.logging.Level;
028    import java.util.logging.Logger;
029    
030    /**
031     * The base class for managing the CRaSH life cycle.
032     */
033    public abstract class PluginLifeCycle {
034    
035      /** . */
036      protected final Logger log = Logger.getLogger(getClass().getName());
037    
038      /** . */
039      private PluginContext context;
040    
041      /** . */
042      private Properties config;
043    
044      public Properties getConfig() {
045        return config;
046      }
047    
048      public void setConfig(Properties config) {
049        this.config = config;
050      }
051    
052      public PluginContext getContext() {
053        return context;
054      }
055    
056      protected final void start(PluginContext context) throws IllegalStateException {
057        if (this.context != null) {
058          throw new IllegalStateException("Already started");
059        }
060        
061        // Get properties from system properties
062        Properties config = new Properties();
063    
064        // Load properties from configuration file
065        Resource res = context.loadResource("crash.properties", ResourceKind.CONFIG);
066        if (res != null) {
067          try {
068            config.load(new ByteArrayInputStream(res.getContent()));
069            log.log(Level.FINE, "Loaded properties from " + config);
070          } catch (IOException e) {
071            log.log(Level.WARNING, "Could not configure from crash.properties", e);
072          }
073        } else {
074          log.log(Level.FINE, "Could not find crash.properties file");
075        }
076    
077        // Override default properties from external config
078        if (this.config != null) {
079          config.putAll(this.config);
080        }
081    
082        // Override default properties from command line
083        for (PropertyDescriptor<?> desc : PropertyDescriptor.ALL.values()) {
084          configureProperty(context, config, desc);
085        }
086    
087        // Override default properties from plugin defined properties.
088        for (final CRaSHPlugin<?> plugin : context.manager.getPlugins())
089        {
090          for (PropertyDescriptor<?> descriptor : plugin.getConfigurationCapabilities()) {
091            configureProperty(context, config, descriptor);
092          }
093        }
094    
095        //
096        context.start();
097    
098        //
099        this.context = context;
100      }
101    
102      public final void stop() throws IllegalStateException {
103        if (context == null) {
104          throw new IllegalStateException("Not started");
105        }
106        PluginContext context = this.context;
107        this.context = null;
108        context.stop();
109      }
110    
111      private void configureProperty(PluginContext context, Properties props, PropertyDescriptor<?> desc) {
112        String key = "crash." + desc.name;
113        String value = props.getProperty(key);
114        if (value != null) {
115          try {
116            if (context.getProperty(desc) == null) {
117              log.log(Level.INFO, "Configuring property " + desc.name + "=" + value + " from properties");
118              context.setProperty(desc, value);
119            }
120          }
121          catch (IllegalArgumentException e) {
122            log.log(Level.SEVERE, "Could not configure property", e);
123          }
124        }
125      }
126    }