1 /*
2 * Licensed to the Apache Software Foundation (ASF) under one or more
3 * contributor license agreements. See the NOTICE file distributed with
4 * this work for additional information regarding copyright ownership.
5 * The ASF licenses this file to You under the Apache License, Version 2.0
6 * (the "License"); you may not use this file except in compliance with
7 * the License. You may obtain a copy of the License at
8 *
9 * http://www.apache.org/licenses/LICENSE-2.0
10 *
11 * Unless required by applicable law or agreed to in writing, software
12 * distributed under the License is distributed on an "AS IS" BASIS,
13 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
14 * See the License for the specific language governing permissions and
15 * limitations under the License.
16 */
17 package org.apache.portals.bridges.jsf;
18
19 import java.util.Enumeration;
20
21 /***
22 * <p>
23 * Enumeration without elements
24 * </p>
25 * <p>
26 * Code provided by MyFaces project.
27 * </p>
28 *
29 * @author <a href="dlestrat@apache.org">David Le Strat </a>
30 */
31 public final class NullEnumeration implements Enumeration
32 {
33 /*** Null enumeration. */
34 private static final NullEnumeration nullEnumeration = new NullEnumeration();
35
36 /***
37 * @return An instance of the enumeration.
38 */
39 public static final NullEnumeration instance()
40 {
41 return nullEnumeration;
42 }
43
44 /***
45 * @see java.util.Enumeration#hasMoreElements()
46 */
47 public boolean hasMoreElements()
48 {
49 return false;
50 }
51
52 /***
53 * @see java.util.Enumeration#nextElement()
54 */
55 public Object nextElement()
56 {
57 throw new UnsupportedOperationException("NullEnumeration has no elements");
58 }
59 }