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 * @author <a href="mailto:dev@directory.apache.org">Apache Directory Project</a>
35 */
36 public class EmptyEnumeration<T> implements NamingEnumeration<T>
37 {
38
39 /**
40 * @see javax.naming.NamingEnumeration#close()
41 */
42 public void close()
43 {
44 }
45
46
47 /**
48 * Always returns false.
49 *
50 * @see javax.naming.NamingEnumeration#hasMore()
51 */
52 public boolean hasMore() throws NamingException
53 {
54 return false;
55 }
56
57
58 /**
59 * Always throws NoSuchElementException.
60 *
61 * @see javax.naming.NamingEnumeration#next()
62 */
63 public T next() throws NamingException
64 {
65 throw new NoSuchElementException();
66 }
67
68
69 /**
70 * Always return false.
71 *
72 * @see java.util.Enumeration#hasMoreElements()
73 */
74 public boolean hasMoreElements()
75 {
76 return false;
77 }
78
79
80 /**
81 * Always throws NoSuchElementException.
82 *
83 * @see java.util.Enumeration#nextElement()
84 */
85 public T nextElement()
86 {
87 throw new NoSuchElementException();
88 }
89
90 }