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1   /*
2    * Copyright 2001-2005 The Apache Software Foundation.
3    *
4    * Licensed under the Apache License, Version 2.0 (the "License")
5    * you may not use this file except in compliance with the License.
6    * You may obtain a copy of the License at
7    *
8    *     http://www.apache.org/licenses/LICENSE-2.0
9    *
10   * Unless required by applicable law or agreed to in writing, software
11   * distributed under the License is distributed on an "AS IS" BASIS,
12   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13   * See the License for the specific language governing permissions and
14   * limitations under the License.
15   */
16  
17  package org.apache.commons.configuration;
18  
19  import java.util.Iterator;
20  import java.util.List;
21  import java.util.Map;
22  import java.util.Properties;
23  import java.util.Vector;
24  
25  import org.apache.commons.collections.ExtendedProperties;
26  import org.apache.commons.lang.StringUtils;
27  
28  /***
29   * Configuration converter. Helper class to convert between Configuration,
30   * ExtendedProperties and standard Properties.
31   *
32   * @author <a href="mailto:mpoeschl@marmot.at">Martin Poeschl</a>
33   * @version $Revision$, $Date: 2005-10-03 20:12:54 +0200 (Mon, 03 Oct 2005) $
34   */
35  public final class ConfigurationConverter
36  {
37      /***
38       * Private constructor prevents instances from being created.
39       */
40      private ConfigurationConverter()
41      {
42          // to prevent instanciation...
43      }
44  
45      /***
46       * Convert a ExtendedProperties class into a Configuration class.
47       *
48       * @param eprops ExtendedProperties object to convert
49       * @return Configuration created from the ExtendedProperties
50       */
51      public static Configuration getConfiguration(ExtendedProperties eprops)
52      {
53          return new MapConfiguration(eprops);
54      }
55  
56      /***
57       * Convert a standard Properties class into a configuration class.
58       *
59       * @param props properties object to convert
60       * @return Configuration configuration created from the Properties
61       */
62      public static Configuration getConfiguration(Properties props)
63      {
64          return new MapConfiguration(props);
65      }
66  
67      /***
68       * Convert a Configuration class into a ExtendedProperties class.
69       *
70       * @param config Configuration object to convert
71       * @return ExtendedProperties created from the Configuration
72       */
73      public static ExtendedProperties getExtendedProperties(Configuration config)
74      {
75          ExtendedProperties props = new ExtendedProperties();
76  
77          Iterator keys = config.getKeys();
78  
79          while (keys.hasNext())
80          {
81              String key = (String) keys.next();
82              Object property = config.getProperty(key);
83  
84              // turn lists into vectors
85              if (property instanceof List)
86              {
87                  property = new Vector((List) property);
88              }
89  
90              props.setProperty(key, property);
91          }
92  
93          return props;
94      }
95  
96      /***
97       * Convert a Configuration class into a Properties class. List properties
98       * are joined into a string using the delimiter of the configuration if it
99       * extends AbstractConfiguration, and a comma otherwise.
100      *
101      * @param config Configuration object to convert
102      * @return Properties created from the Configuration
103      */
104     public static Properties getProperties(Configuration config)
105     {
106         Properties props = new Properties();
107 
108         char delimiter = (config instanceof AbstractConfiguration)
109             ? ((AbstractConfiguration) config).getDelimiter() : ',';
110 
111         Iterator keys = config.getKeys();
112         while (keys.hasNext())
113         {
114             String key = (String) keys.next();
115             List list = config.getList(key);
116 
117             // turn the list into a string
118             props.setProperty(key, StringUtils.join(list.iterator(), delimiter));
119         }
120 
121         return props;
122     }
123 
124     /***
125      * Convert a Configuration class into a Map class.
126      *
127      * @param config Configuration object to convert
128      * @return Map created from the Configuration
129      */
130     public static Map getMap(Configuration config)
131     {
132         return new ConfigurationMap(config);
133     }
134 
135 }