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 1.4 2005/10/18 13:24:19 mungady Exp $
036     *
037     * Changes
038     * -------
039     * 04.06.2003 : Initial version (TM);
040     *
041     */
042    
043    package org.jfree.util;
044    
045    import java.util.Collections;
046    import java.util.Enumeration;
047    import java.util.Iterator;
048    import java.util.Properties;
049    import java.util.TreeSet;
050    
051    /**
052     * Default configuration.
053     * 
054     * @author Thomas Morgner.
055     * 
056     */
057    public class DefaultConfiguration extends Properties implements Configuration {
058    
059        /**
060         * Creates an empty property list with no default values.
061         */
062        public DefaultConfiguration() {
063            super();
064        }
065    
066        /**
067         * Returns the configuration property with the specified key.
068         *
069         * @param key  the property key.
070         *
071         * @return the property value.
072         */
073        public String getConfigProperty(final String key) {
074            return getProperty(key);
075        }
076    
077        /**
078         * Returns the configuration property with the specified key (or the specified default value
079         * if there is no such property).
080         * <p>
081         * If the property is not defined in this configuration, the code will lookup the property in
082         * the parent configuration.
083         *
084         * @param key  the property key.
085         * @param defaultValue  the default value.
086         *
087         * @return the property value.
088         */
089        public String getConfigProperty(final String key, final String defaultValue) {
090            return getProperty(key, defaultValue);
091        }
092    
093        /**
094         * Searches all property keys that start with a given prefix.
095         *
096         * @param prefix the prefix that all selected property keys should share
097         * @return the properties as iterator.
098         */
099        public Iterator findPropertyKeys(final String prefix) {
100            final TreeSet collector = new TreeSet();
101            final Enumeration enum1 = keys();
102            while (enum1.hasMoreElements()) {
103                final String key = (String) enum1.nextElement();
104                if (key.startsWith(prefix)) {
105                    if (collector.contains(key) == false) {
106                        collector.add(key);
107                    }
108                }
109            }
110            return Collections.unmodifiableSet(collector).iterator();
111        }
112    
113        public Enumeration getConfigProperties()
114        {
115          return keys();
116        }
117    }