Source for org.jfree.util.DefaultConfiguration

   1: /* ========================================================================
   2:  * JCommon : a free general purpose class library for the Java(tm) platform
   3:  * ========================================================================
   4:  *
   5:  * (C) Copyright 2000-2005, by Object Refinery Limited and Contributors.
   6:  * 
   7:  * Project Info:  http://www.jfree.org/jcommon/index.html
   8:  *
   9:  * This library is free software; you can redistribute it and/or modify it 
  10:  * under the terms of the GNU Lesser General Public License as published by 
  11:  * the Free Software Foundation; either version 2.1 of the License, or 
  12:  * (at your option) any later version.
  13:  *
  14:  * This library is distributed in the hope that it will be useful, but 
  15:  * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY 
  16:  * or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public 
  17:  * License for more details.
  18:  *
  19:  * You should have received a copy of the GNU Lesser General Public
  20:  * License along with this library; if not, write to the Free Software
  21:  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, 
  22:  * USA.  
  23:  *
  24:  * [Java is a trademark or registered trademark of Sun Microsystems, Inc. 
  25:  * in the United States and other countries.]
  26:  * 
  27:  * -------------------------
  28:  * DefaultConfiguration.java
  29:  * -------------------------
  30:  * (C)opyright 2003, 2004, by Thomas Morgner and Contributors.
  31:  *
  32:  * Original Author:  Thomas Morgner;
  33:  * Contributor(s):   David Gilbert (for Object Refinery Limited);
  34:  *
  35:  * $Id: DefaultConfiguration.java,v 1.4 2005/10/18 13:24:19 mungady Exp $
  36:  *
  37:  * Changes
  38:  * -------
  39:  * 04.06.2003 : Initial version (TM);
  40:  *
  41:  */
  42: 
  43: package org.jfree.util;
  44: 
  45: import java.util.Collections;
  46: import java.util.Enumeration;
  47: import java.util.Iterator;
  48: import java.util.Properties;
  49: import java.util.TreeSet;
  50: 
  51: /**
  52:  * Default configuration.
  53:  * 
  54:  * @author Thomas Morgner.
  55:  * 
  56:  */
  57: public class DefaultConfiguration extends Properties implements Configuration {
  58: 
  59:     /**
  60:      * Creates an empty property list with no default values.
  61:      */
  62:     public DefaultConfiguration() {
  63:         super();
  64:     }
  65: 
  66:     /**
  67:      * Returns the configuration property with the specified key.
  68:      *
  69:      * @param key  the property key.
  70:      *
  71:      * @return the property value.
  72:      */
  73:     public String getConfigProperty(final String key) {
  74:         return getProperty(key);
  75:     }
  76: 
  77:     /**
  78:      * Returns the configuration property with the specified key (or the specified default value
  79:      * if there is no such property).
  80:      * <p>
  81:      * If the property is not defined in this configuration, the code will lookup the property in
  82:      * the parent configuration.
  83:      *
  84:      * @param key  the property key.
  85:      * @param defaultValue  the default value.
  86:      *
  87:      * @return the property value.
  88:      */
  89:     public String getConfigProperty(final String key, final String defaultValue) {
  90:         return getProperty(key, defaultValue);
  91:     }
  92: 
  93:     /**
  94:      * Searches all property keys that start with a given prefix.
  95:      *
  96:      * @param prefix the prefix that all selected property keys should share
  97:      * @return the properties as iterator.
  98:      */
  99:     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: }