    001/* ========================================================================
    002 * JCommon : a free general purpose class library for the Java(tm) platform
    003 * ========================================================================
    004 *
    005 * (C) Copyright 2000-2005, by Object Refinery Limited and Contributors.
    006 *
    007 * Project Info:  http://www.jfree.org/jcommon/index.html
    008 *
    009 * This library is free software; you can redistribute it and/or modify it
    010 * under the terms of the GNU Lesser General Public License as published by
    011 * the Free Software Foundation; either version 2.1 of the License, or
    012 * (at your option) any later version.
    013 *
    014 * This library is distributed in the hope that it will be useful, but
    015 * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
    016 * or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public
    017 * License for more details.
    018 *
    019 * You should have received a copy of the GNU Lesser General Public
    020 * License along with this library; if not, write to the Free Software
    021 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301,
    022 * USA.
    023 *
    024 * [Java is a trademark or registered trademark of Sun Microsystems, Inc.
    025 * in the United States and other countries.]
    026 *
    027 * -------------------------
    028 * DefaultConfiguration.java
    029 * -------------------------
    030 * (C)opyright 2003, 2004, by Thomas Morgner and Contributors.
    031 *
    032 * Original Author:  Thomas Morgner;
    033 * Contributor(s):   David Gilbert (for Object Refinery Limited);
    034 *
    035 * $Id: DefaultConfiguration.java,v 1.6 2008/09/10 09:21:30 mungady Exp $
    036 *
    037 * Changes
    038 * -------
    039 * 04.06.2003 : Initial version (TM);
    040 *
    041 */
    042
    043package org.jfree.util;
    044
    045import java.util.Collections;
    046import java.util.Enumeration;
    047import java.util.Iterator;
    048import java.util.Properties;
    049import java.util.TreeSet;
    050
    051import org.jfree.base.config.ModifiableConfiguration;
    052
    053/**
    054 * Default configuration.
    055 *
    056 * @author Thomas Morgner.
    057 */
    058public class DefaultConfiguration extends Properties
    059    implements ModifiableConfiguration
    060{
    061
    062  /**
    063   * Creates an empty property list with no default values.
    064   */
    065  public DefaultConfiguration()
    066  {
    067    super();
    068  }
    069
    070  /**
    071   * Returns the configuration property with the specified key.
    072   *
    073   * @param key the property key.
    074   * @return the property value.
    075   */
    076  public String getConfigProperty(final String key)
    077  {
    078    return getProperty(key);
    079  }
    080
    081  /**
    082   * Returns the configuration property with the specified key (or the
    083   * specified default value if there is no such property).
    084   * <p/>
    085   * If the property is not defined in this configuration, the code will
    086   * lookup the property in the parent configuration.
    087   *
    088   * @param key          the property key.
    089   * @param defaultValue the default value.
    090   * @return the property value.
    091   */
    092  public String getConfigProperty(final String key, final String defaultValue)
    093  {
    094    return getProperty(key, defaultValue);
    095  }
    096
    097  /**
    098   * Searches all property keys that start with a given prefix.
    099   *
    100   * @param prefix the prefix that all selected property keys should share
    101   * @return the properties as iterator.
    102   */
    103  public Iterator findPropertyKeys(final String prefix)
    104  {
    105    final TreeSet collector = new TreeSet();
    106    final Enumeration enum1 = keys();
    107    while (enum1.hasMoreElements())
    108    {
    109      final String key = (String) enum1.nextElement();
    110      if (key.startsWith(prefix))
    111      {
    112        if (collector.contains(key) == false)
    113        {
    114          collector.add(key);
    115        }
    116      }
    117    }
    118    return Collections.unmodifiableSet(collector).iterator();
    119  }
    120
    121  /**
    122   * Returns an enumeration of the property keys.
    123   *
    124   * @return An enumeration of the property keys.
    125   */
    126  public Enumeration getConfigProperties()
    127  {
    128    return keys();
    129  }
    130
    131  /**
    132   * Sets the value of a configuration property.
    133   *
    134   * @param key   the property key.
    135   * @param value the property value.
    136   */
    137  public void setConfigProperty(final String key, final String value)
    138  {
    139    if (value == null)
    140    {
    141      remove(key);
    142    }
    143    else
    144    {
    145      setProperty(key, value);
    146    }
    147  }
    148}