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1   /*
2    * Copyright 2004 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.web;
18  
19  import java.util.Iterator;
20  import java.util.List;
21  import javax.servlet.Servlet;
22  import javax.servlet.ServletContext;
23  
24  import org.apache.commons.collections.iterators.EnumerationIterator;
25  import org.apache.commons.configuration.AbstractConfiguration;
26  import org.apache.commons.configuration.PropertyConverter;
27  
28  /***
29   * A configuration wrapper to read the initialization parameters of a servlet
30   * context. This configuration is read only, adding or removing a property will
31   * throw an UnsupportedOperationException.
32   *
33   * @author <a href="mailto:ebourg@apache.org">Emmanuel Bourg</a>
34   * @version $Revision: 155408 $, $Date: 2005-02-26 13:56:39 +0100 (Sa, 26 Feb 2005) $
35   * @since 1.1
36   */
37  public class ServletContextConfiguration extends AbstractConfiguration
38  {
39      protected ServletContext context;
40  
41      /***
42       * Create a ServletContextConfiguration using the context of
43       * the specified servlet.
44       *
45       * @param servlet the servlet
46       */
47      public ServletContextConfiguration(Servlet servlet)
48      {
49          this.context = servlet.getServletConfig().getServletContext();
50      }
51  
52      /***
53       * Create a ServletContextConfiguration using the servlet context
54       * initialization parameters.
55       *
56       * @param context the servlet context
57       */
58      public ServletContextConfiguration(ServletContext context)
59      {
60          this.context = context;
61      }
62  
63      public Object getProperty(String key)
64      {
65          Object value = context.getInitParameter(key);
66          List list = PropertyConverter.split((String) value, getDelimiter());
67  
68          return list.size() > 1 ? list : value;
69      }
70  
71      /***
72       * <p><strong>This operation is not supported and will throw an
73       * UnsupportedOperationException.</strong></p>
74       *
75       * @throws UnsupportedOperationException
76       */
77      protected void addPropertyDirect(String key, Object obj)
78      {
79          throw new UnsupportedOperationException("Read only configuration");
80      }
81  
82      public boolean isEmpty()
83      {
84          return !getKeys().hasNext();
85      }
86  
87      public boolean containsKey(String key)
88      {
89          return getProperty(key) != null;
90      }
91  
92      /***
93       * <p><strong>This operation is not supported and will throw an
94       * UnsupportedOperationException.</strong></p>
95       *
96       * @throws UnsupportedOperationException
97       */
98      public void clearProperty(String key)
99      {
100         throw new UnsupportedOperationException("Read only configuration");
101     }
102 
103     public Iterator getKeys()
104     {
105         return new EnumerationIterator(context.getInitParameterNames());
106     }
107 }