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 */
20 package org.apache.directory.api.util;
21
22
23 import java.util.NoSuchElementException;
24
25 import javax.naming.NamingException;
26 import javax.naming.NamingEnumeration;
27
28
29 /**
30 * An empty NamingEnumeration without any values: meaning
31 * hasMore/hasMoreElements() always returns false, and next/nextElement() always
32 * throws a NoSuchElementException.
33 *
34 * @param <T> The element in the enumeration
35 *
36 * @author <a href="mailto:dev@directory.apache.org">Apache Directory Project</a>
37 */
38 public class EmptyEnumeration<T> implements NamingEnumeration<T>
39 {
40 /**
41 * @see javax.naming.NamingEnumeration#close()
42 */
43 public void close()
44 {
45 }
46
47
48 /**
49 * Always returns false.
50 *
51 * @see javax.naming.NamingEnumeration#hasMore()
52 */
53 public boolean hasMore() throws NamingException
54 {
55 return false;
56 }
57
58
59 /**
60 * Always throws NoSuchElementException.
61 *
62 * @see javax.naming.NamingEnumeration#next()
63 */
64 public T next() throws NamingException
65 {
66 throw new NoSuchElementException();
67 }
68
69
70 /**
71 * Always return false.
72 *
73 * @see java.util.Enumeration#hasMoreElements()
74 */
75 public boolean hasMoreElements()
76 {
77 return false;
78 }
79
80
81 /**
82 * Always throws NoSuchElementException.
83 *
84 * @see java.util.Enumeration#nextElement()
85 */
86 public T nextElement()
87 {
88 throw new NoSuchElementException();
89 }
90
91 }