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1   /*
2    * Licensed to the Apache Software Foundation (ASF) under one
3    * or more contributor license agreements.  See the NOTICE file
4    * distributed with this work for additional information
5    * regarding copyright ownership.  The ASF licenses this file
6    * to you under the Apache License, Version 2.0 (the
7    * "License"); you may not use this file except in compliance
8    * with the License.  You may obtain a copy of the License at
9    *
10   *   http://www.apache.org/licenses/LICENSE-2.0
11   *
12   * Unless required by applicable law or agreed to in writing,
13   * software distributed under the License is distributed on an
14   * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
15   * KIND, either express or implied.  See the License for the
16   * specific language governing permissions and limitations
17   * under the License.
18   */
19  package org.apache.myfaces.shared.util;
20  
21  import java.util.Enumeration;
22  import java.util.NoSuchElementException;
23  
24  /**
25   * Enumeration without elements
26   *
27   * @author Anton Koinov (latest modification by $Author: lu4242 $)
28   * @version $Revision: 1200044 $ $Date: 2011-11-09 18:44:02 -0500 (Wed, 09 Nov 2011) $
29   */
30  public final class NullEnumeration implements Enumeration
31  {
32      private static final NullEnumeration NULL_ENUMERATION = new NullEnumeration();
33  
34      public static final NullEnumeration instance()
35      {
36          return NULL_ENUMERATION;
37      }
38  
39      public boolean hasMoreElements()
40      {
41          return false;
42      }
43  
44      public Object nextElement()
45      {
46          throw new NoSuchElementException("NullEnumeration has no elements");
47      }
48  }