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Java > Open Source Codes > org > apache > commons > configuration > web > ServletContextConfiguration


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 JavaDoc;
20 import java.util.List JavaDoc;
21 import javax.servlet.Servlet JavaDoc;
22 import javax.servlet.ServletContext JavaDoc;
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 JavaDoc 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 JavaDoc 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 JavaDoc context)
59     {
60         this.context = context;
61     }
62
63     public Object JavaDoc getProperty(String JavaDoc key)
64     {
65         Object JavaDoc value = context.getInitParameter(key);
66         List JavaDoc list = PropertyConverter.split((String JavaDoc) 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 JavaDoc key, Object JavaDoc obj)
78     {
79         throw new UnsupportedOperationException JavaDoc("Read only configuration");
80     }
81
82     public boolean isEmpty()
83     {
84         return !getKeys().hasNext();
85     }
86
87     public boolean containsKey(String JavaDoc 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 JavaDoc key)
99     {
100         throw new UnsupportedOperationException JavaDoc("Read only configuration");
101     }
102
103     public Iterator JavaDoc getKeys()
104     {
105         return new EnumerationIterator(context.getInitParameterNames());
106     }
107 }
108
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