content: /* ========================================================================
   * JCommon : a free general purpose class library for the Java(tm) platform
   * ========================================================================
   *
   * (C) Copyright 2000-2005, by Object Refinery Limited and Contributors.
   * 
   * Project Info:  http://www.jfree.org/jcommon/index.html
   *
   * This library is free software; you can redistribute it and/or modify it 
   * under the terms of the GNU Lesser General Public License as published by 
   * the Free Software Foundation; either version 2.1 of the License, or 
   * (at your option) any later version.
   *
   * This library is distributed in the hope that it will be useful, but 
   * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY 
   * or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public 
   * License for more details.
   *
   * You should have received a copy of the GNU Lesser General Public
   * License along with this library; if not, write to the Free Software
   * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, 
   * USA.  
   *
   * [Java is a trademark or registered trademark of Sun Microsystems, Inc. 
   * in the United States and other countries.]
   * 
   * ------------------
   * Configuration.java
   * ------------------
   * (C)opyright 2002-2005, by Thomas Morgner and Contributors.
   *
   * Original Author:  Thomas Morgner (taquera@sherito.org);
   * Contributor(s):   David Gilbert (for Object Refinery Limited);
   *
   * $Id: Configuration.java,v 1.8 2007/11/02 17:50:37 taqua Exp $
   *
   * Changes
   * -------
   * 02-May-2003 : Initial version (TM);
   * 
   */
  
  package org.jfree.util;
  
  import java.io.Serializable;
  import java.util.Enumeration;
  import java.util.Iterator;
  
  /**
   * A simple query interface for a configuration.
   *
   * @author Thomas Morgner
   */
  public interface Configuration extends Serializable, Cloneable {
  
      /**
       * Returns the configuration property with the specified key.
       *
       * @param key  the property key.
       *
       * @return the property value.
       */
      public String getConfigProperty(String key);
  
      /**
       * Returns the configuration property with the specified key (or the 
       * specified default value if there is no such property).
       * <p>
       * If the property is not defined in this configuration, the code will 
       * lookup the property in the parent configuration.
       *
       * @param key  the property key.
       * @param defaultValue  the default value.
       *
       * @return the property value.
       */
      public String getConfigProperty(String key, String defaultValue);
  
      /**
       * Returns all keys with the given prefix.
       *
       * @param prefix the prefix
       * @return the iterator containing all keys with that prefix
       */
      public Iterator findPropertyKeys(String prefix);
  
      /**
       * Returns the configuration properties.
       * 
       * @return The configuration properties.
       */
      public Enumeration getConfigProperties();
    
      /**
       * Returns a clone of the object.
       *
       * @return A clone.
       *
       * @throws CloneNotSupportedException if cloning is not supported for some reason.
       */
      public Object clone() throws CloneNotSupportedException;
  
  }
  