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 javax.naming.NamingEnumeration;
24
25 import java.util.NoSuchElementException;
26
27
28 /**
29 * A NamingEnumeration over a single element.
30 *
31 * @author <a href="mailto:dev@directory.apache.org">Apache Directory Project</a>
32 */
33 public class SingletonEnumeration<T> implements NamingEnumeration<T>
34 {
35 /** The singleton element to return */
36 private final T element;
37
38 /** Can we return a element */
39 private boolean hasMore = true;
40
41
42 /**
43 * Creates a NamingEnumeration over a single element.
44 *
45 * @param element
46 * TODO
47 */
48 public SingletonEnumeration( final T element )
49 {
50 this.element = element;
51 }
52
53
54 /**
55 * Makes calls to hasMore to false even if we had more.
56 *
57 * @see javax.naming.NamingEnumeration#close()
58 */
59 public void close()
60 {
61 hasMore = false;
62 }
63
64
65 /**
66 * @see javax.naming.NamingEnumeration#hasMore()
67 */
68 public boolean hasMore()
69 {
70 return hasMore;
71 }
72
73
74 /**
75 * @see javax.naming.NamingEnumeration#next()
76 */
77 public T next()
78 {
79 if ( hasMore )
80 {
81 hasMore = false;
82 return element;
83 }
84
85 throw new NoSuchElementException();
86 }
87
88
89 /**
90 * @see java.util.Enumeration#hasMoreElements()
91 */
92 public boolean hasMoreElements()
93 {
94 return hasMore;
95 }
96
97
98 /**
99 * @see java.util.Enumeration#nextElement()
100 */
101 public T nextElement()
102 {
103 return next();
104 }
105 }