package org.codehaus.plexus.component.configurator.converters.composite;
   
   /*
    * The MIT License
    *
    * Copyright (c) 2004, The Codehaus
    *
    * Permission is hereby granted, free of charge, to any person obtaining a copy of
    * this software and associated documentation files (the "Software"), to deal in
   * the Software without restriction, including without limitation the rights to
   * use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies
   * of the Software, and to permit persons to whom the Software is furnished to do
   * so, subject to the following conditions:
   *
   * The above copyright notice and this permission notice shall be included in all
   * copies or substantial portions of the Software.
   *
   * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
   * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
   * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
   * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
   * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
   * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
   * SOFTWARE.
   */
  
  import java.util.Properties;
  
  import org.codehaus.plexus.component.configurator.ComponentConfigurationException;
  import org.codehaus.plexus.component.configurator.ConfigurationListener;
  import org.codehaus.plexus.component.configurator.converters.AbstractConfigurationConverter;
  import org.codehaus.plexus.component.configurator.converters.lookup.ConverterLookup;
  import org.codehaus.plexus.component.configurator.expression.ExpressionEvaluator;
  import org.codehaus.plexus.configuration.PlexusConfiguration;
  
  /**
   * Converter for <code>java.util.Properties</code>.
   *
   * @author <a href="mailto:michal@codehaus.org">Michal Maczka</a>
   */
  public class PropertiesConverter extends AbstractConfigurationConverter {
      public boolean canConvert(Class type) {
          return Properties.class.isAssignableFrom(type);
      }
  
      public Object fromConfiguration(
              ConverterLookup converterLookup,
              PlexusConfiguration configuration,
              Class type,
              Class baseType,
              ClassLoader classLoader,
              ExpressionEvaluator expressionEvaluator,
              ConfigurationListener listener)
              throws ComponentConfigurationException {
  
          Object retValueInterpolated = fromExpression(configuration, expressionEvaluator, type);
          if (retValueInterpolated != null) {
              return retValueInterpolated;
          }
  
          String element = configuration.getName();
  
          Properties retValue = new Properties();
  
          PlexusConfiguration[] children = configuration.getChildren("property");
  
          if (children != null && children.length > 0) {
              for (PlexusConfiguration child : children) {
                  addEntry(retValue, element, child, expressionEvaluator);
              }
          }
  
          return retValue;
      }
  
      private void addEntry(
              Properties properties,
              String element,
              PlexusConfiguration property,
              ExpressionEvaluator expressionEvaluator)
              throws ComponentConfigurationException {
          Object name = fromExpression(property.getChild("name"), expressionEvaluator);
  
          if (name == null) {
              String msg = "Trying to convert the configuration element: '" + element
                      + "', missing child element 'name' for property.";
  
              throw new ComponentConfigurationException(msg);
          }
  
          Object value = fromExpression(property.getChild("value"), expressionEvaluator);
  
          if (value == null) {
              properties.setProperty(name.toString(), "");
          } else {
              properties.setProperty(name.toString(), value.toString());
          }
      }
  }