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1   /*
2    * $Id$
3    *
4    * Licensed to the Apache Software Foundation (ASF) under one
5    * or more contributor license agreements.  See the NOTICE file
6    * distributed with this work for additional information
7    * regarding copyright ownership.  The ASF licenses this file
8    * to you under the Apache License, Version 2.0 (the
9    * "License"); you may not use this file except in compliance
10   * with the License.  You may obtain a copy of the License at
11   *
12   *  http://www.apache.org/licenses/LICENSE-2.0
13   *
14   * Unless required by applicable law or agreed to in writing,
15   * software distributed under the License is distributed on an
16   * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
17   * KIND, either express or implied.  See the License for the
18   * specific language governing permissions and limitations
19   * under the License.
20   */
21  package org.apache.struts.util;
22  
23  import java.util.Enumeration;
24  import java.util.Iterator;
25  import java.util.NoSuchElementException;
26  
27  /**
28   * Utility method for converting Enumeration to an Iterator class.  If you
29   * attempt to remove() an Object from the iterator, it will throw an
30   * UnsupportedOperationException. Added for use by TagLib so Enumeration can
31   * be supported
32   *
33   * @version $Rev$ $Date: 2005-05-07 12:11:38 -0400 (Sat, 07 May 2005)
34   *          $
35   */
36  public class IteratorAdapter<E> implements Iterator<E> {
37      private Enumeration<E> e;
38  
39      public IteratorAdapter(Enumeration<E> e) {
40          this.e = e;
41      }
42  
43      public boolean hasNext() {
44          return e.hasMoreElements();
45      }
46  
47      public E next() {
48          if (!e.hasMoreElements()) {
49              throw new NoSuchElementException(
50                  "IteratorAdaptor.next() has no more elements");
51          }
52  
53          return e.nextElement();
54      }
55  
56      public void remove() {
57          throw new UnsupportedOperationException(
58              "Method IteratorAdaptor.remove() not implemented");
59      }
60  }