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1   /*
2    * Licensed to the Apache Software Foundation (ASF) under one or more
3    * contributor license agreements.  See the NOTICE file distributed with
4    * this work for additional information regarding copyright ownership.
5    * The ASF licenses this file to You under the Apache License, Version 2.0
6    * (the "License"); you may not use this file except in compliance with
7    * the License.  You may obtain a copy of the License at
8    *
9    *     http://www.apache.org/licenses/LICENSE-2.0
10   *
11   * Unless required by applicable law or agreed to in writing, software
12   * distributed under the License is distributed on an "AS IS" BASIS,
13   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
14   * See the License for the specific language governing permissions and
15   * limitations under the License.
16   */
17  
18  package org.apache.commons.configuration;
19  
20  import java.util.Iterator;
21  import java.util.List;
22  import java.util.Map;
23  import java.util.Properties;
24  import java.util.Vector;
25  
26  import org.apache.commons.collections.ExtendedProperties;
27  import org.apache.commons.lang.StringUtils;
28  
29  /***
30   * Configuration converter. Helper class to convert between Configuration,
31   * ExtendedProperties and standard Properties.
32   *
33   * @author <a href="mailto:mpoeschl@marmot.at">Martin Poeschl</a>
34   * @version $Revision: 439648 $, $Date: 2006-09-02 22:42:10 +0200 (Sa, 02 Sep 2006) $
35   */
36  public final class ConfigurationConverter
37  {
38      /***
39       * Private constructor prevents instances from being created.
40       */
41      private ConfigurationConverter()
42      {
43          // to prevent instanciation...
44      }
45  
46      /***
47       * Convert a ExtendedProperties class into a Configuration class.
48       *
49       * @param eprops ExtendedProperties object to convert
50       * @return Configuration created from the ExtendedProperties
51       */
52      public static Configuration getConfiguration(ExtendedProperties eprops)
53      {
54          return new MapConfiguration(eprops);
55      }
56  
57      /***
58       * Convert a standard Properties class into a configuration class.
59       *
60       * @param props properties object to convert
61       * @return Configuration configuration created from the Properties
62       */
63      public static Configuration getConfiguration(Properties props)
64      {
65          return new MapConfiguration(props);
66      }
67  
68      /***
69       * Convert a Configuration class into a ExtendedProperties class.
70       *
71       * @param config Configuration object to convert
72       * @return ExtendedProperties created from the Configuration
73       */
74      public static ExtendedProperties getExtendedProperties(Configuration config)
75      {
76          ExtendedProperties props = new ExtendedProperties();
77  
78          Iterator keys = config.getKeys();
79  
80          while (keys.hasNext())
81          {
82              String key = (String) keys.next();
83              Object property = config.getProperty(key);
84  
85              // turn lists into vectors
86              if (property instanceof List)
87              {
88                  property = new Vector((List) property);
89              }
90  
91              props.setProperty(key, property);
92          }
93  
94          return props;
95      }
96  
97      /***
98       * Convert a Configuration class into a Properties class. List properties
99       * are joined into a string using the delimiter of the configuration if it
100      * extends AbstractConfiguration, and a comma otherwise.
101      *
102      * @param config Configuration object to convert
103      * @return Properties created from the Configuration
104      */
105     public static Properties getProperties(Configuration config)
106     {
107         Properties props = new Properties();
108 
109         char delimiter = (config instanceof AbstractConfiguration)
110             ? ((AbstractConfiguration) config).getListDelimiter() : ',';
111 
112         Iterator keys = config.getKeys();
113         while (keys.hasNext())
114         {
115             String key = (String) keys.next();
116             List list = config.getList(key);
117 
118             // turn the list into a string
119             props.setProperty(key, StringUtils.join(list.iterator(), delimiter));
120         }
121 
122         return props;
123     }
124 
125     /***
126      * Convert a Configuration class into a Map class.
127      *
128      * @param config Configuration object to convert
129      * @return Map created from the Configuration
130      */
131     public static Map getMap(Configuration config)
132     {
133         return new ConfigurationMap(config);
134     }
135 
136 }