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Java > Open Source Codes > org > jfree > util > ExtendedConfigurationWrapper


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  * ExtendedConfigurationWrapper.java
29  * ---------------------------------
30  * (C)opyright 2002-2005, by Thomas Morgner and Contributors.
31  *
32  * Original Author: Thomas Morgner;
33  * Contributor(s): David Gilbert (for Object Refinery Limited);
34  *
35  * $Id: ExtendedConfigurationWrapper.java,v 1.6 2006/11/20 21:36:30 taqua Exp $
36  *
37  * Changes
38  * -------
39  * 20-May-2005 : Initial version.
40  */
41
42 package org.jfree.util;
43
44 import java.util.Iterator JavaDoc;
45 import java.util.Enumeration JavaDoc;
46
47 /**
48  * A wrapper for the extended configuration interface around a plain configuration.
49  *
50  * @author Thomas Morgner
51  */
52 public class ExtendedConfigurationWrapper
53         implements ExtendedConfiguration
54 {
55   /** The base configuration. */
56   private Configuration parent;
57
58   /**
59    * Creates a wrapper around the given configuration.
60    *
61    * @param parent the wrapped up configuration.
62    * @throws NullPointerException if the parent is null.
63    */
64   public ExtendedConfigurationWrapper (final Configuration parent)
65   {
66     if (parent == null)
67     {
68       throw new NullPointerException JavaDoc("Parent given must not be null");
69     }
70     this.parent = parent;
71   }
72
73   /**
74    * Returns the boolean value of a given configuration property. The boolean value true
75    * is returned, if the contained string is equal to 'true'.
76    *
77    * @param name the name of the property
78    * @return the boolean value of the property.
79    */
80   public boolean getBoolProperty (final String JavaDoc name)
81   {
82     return getBoolProperty(name, false);
83   }
84
85   /**
86    * Returns the boolean value of a given configuration property. The boolean value true
87    * is returned, if the contained string is equal to 'true'. If the property is not set,
88    * the default value is returned.
89    *
90    * @param name the name of the property
91    * @param defaultValue the default value to be returned if the property is not set
92    * @return the boolean value of the property.
93    */
94   public boolean getBoolProperty (final String JavaDoc name,
95                                   final boolean defaultValue)
96   {
97     return "true".equals(parent.getConfigProperty(name, String.valueOf(defaultValue)));
98   }
99
100   /**
101    * Returns a given property as int value. Zero is returned if the
102    * property value is no number or the property is not set.
103    *
104    * @param name the name of the property
105    * @return the parsed number value or zero
106    */
107   public int getIntProperty (final String JavaDoc name)
108   {
109     return getIntProperty(name, 0);
110   }
111
112   /**
113    * Returns a given property as int value. The specified default value is returned if the
114    * property value is no number or the property is not set.
115    *
116    * @param name the name of the property
117    * @param defaultValue the value to be returned if the property is no integer value
118    * @return the parsed number value or the specified default value
119    */
120   public int getIntProperty (final String JavaDoc name,
121                              final int defaultValue)
122   {
123     final String JavaDoc retval = parent.getConfigProperty(name);
124     if (retval == null)
125     {
126       return defaultValue;
127     }
128     try
129     {
130       return Integer.parseInt(retval);
131     }
132     catch (Exception JavaDoc e)
133     {
134       return defaultValue;
135     }
136   }
137
138   /**
139    * Checks, whether a given property is defined.
140    *
141    * @param name the name of the property
142    * @return true, if the property is defined, false otherwise.
143    */
144   public boolean isPropertySet (final String JavaDoc name)
145   {
146     return parent.getConfigProperty(name) != null;
147   }
148
149   /**
150    * Returns all keys with the given prefix.
151    *
152    * @param prefix the prefix
153    * @return the iterator containing all keys with that prefix
154    */
155   public Iterator JavaDoc findPropertyKeys (final String JavaDoc prefix)
156   {
157     return parent.findPropertyKeys(prefix);
158   }
159
160   /**
161    * Returns the configuration property with the specified key.
162    *
163    * @param key the property key.
164    * @return the property value.
165    */
166   public String JavaDoc getConfigProperty (final String JavaDoc key)
167   {
168     return parent.getConfigProperty(key);
169   }
170
171   /**
172    * Returns the configuration property with the specified key (or the specified default
173    * value if there is no such property).
174    * <p/>
175    * If the property is not defined in this configuration, the code will lookup the
176    * property in the parent configuration.
177    *
178    * @param key the property key.
179    * @param defaultValue the default value.
180    * @return the property value.
181    */
182   public String JavaDoc getConfigProperty (final String JavaDoc key, final String JavaDoc defaultValue)
183   {
184     return parent.getConfigProperty(key, defaultValue);
185   }
186
187   public Enumeration JavaDoc getConfigProperties()
188   {
189     return parent.getConfigProperties();
190   }
191
192   public Object JavaDoc clone () throws CloneNotSupportedException JavaDoc
193   {
194     ExtendedConfigurationWrapper wrapper = (ExtendedConfigurationWrapper) super.clone();
195     wrapper.parent = (Configuration) parent.clone();
196     return parent;
197   }
198 }
199
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