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
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 import org.jfree.base.config.ModifiableConfiguration;
052
053 /**
054 * Default configuration.
055 *
056 * @author Thomas Morgner.
057 */
058 public 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 }