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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.applet.Applet;
20  import java.util.Iterator;
21  import java.util.List;
22  
23  import org.apache.commons.collections.iterators.ArrayIterator;
24  import org.apache.commons.configuration.AbstractConfiguration;
25  import org.apache.commons.configuration.PropertyConverter;
26  
27  /***
28   * A configuration wrapper to read applet parameters. This configuration is
29   * read only, adding or removing a property will throw an
30   * UnsupportedOperationException.
31   *
32   * @author <a href="mailto:ebourg@apache.org">Emmanuel Bourg</a>
33   * @version $Revision: 155408 $, $Date: 2005-02-26 13:56:39 +0100 (Sa, 26 Feb 2005) $
34   * @since 1.1
35   */
36  public class AppletConfiguration extends AbstractConfiguration
37  {
38      protected Applet applet;
39  
40      /***
41       * Create an AppletConfiguration using the initialization parameters of
42       * the specified Applet.
43       *
44       * @param applet
45       */
46      public AppletConfiguration(Applet applet)
47      {
48          this.applet = applet;
49      }
50  
51      public Object getProperty(String key)
52      {
53          Object value = applet.getParameter(key);
54          List list = PropertyConverter.split((String) value, getDelimiter());
55  
56          return list.size() > 1 ? list : value;
57      }
58  
59      /***
60       * <p><strong>This operation is not supported and will throw an
61       * UnsupportedOperationException.</strong></p>
62       *
63       * @throws UnsupportedOperationException
64       */
65      protected void addPropertyDirect(String key, Object obj)
66      {
67          throw new UnsupportedOperationException("Read only configuration");
68      }
69  
70      public boolean isEmpty()
71      {
72          return !getKeys().hasNext();
73      }
74  
75      public boolean containsKey(String key)
76      {
77          return getProperty(key) != null;
78      }
79  
80      /***
81       * <p><strong>This operation is not supported and will throw an
82       * UnsupportedOperationException.</strong></p>
83       *
84       * @throws UnsupportedOperationException
85       */
86      public void clearProperty(String key)
87      {
88          throw new UnsupportedOperationException("Read only configuration");
89      }
90  
91      public Iterator getKeys()
92      {
93          String[][] paramsInfo = applet.getParameterInfo();
94          String[] keys = new String[paramsInfo != null ? paramsInfo.length : 0];
95          for (int i = 0; i < keys.length; i++)
96          {
97              keys[i] = paramsInfo[i][0];
98          }
99  
100         return new ArrayIterator(keys);
101     }
102 }