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 * @param <T> The element in the enumeration
33 */
34 public class SingletonEnumeration<T> implements NamingEnumeration<T>
35 {
36 /** The singleton element to return */
37 private final T element;
38
39 /** Can we return a element */
40 private boolean hasMore = true;
41
42
43 /**
44 * Creates a NamingEnumeration over a single element.
45 *
46 * @param element
47 * TODO
48 */
49 public SingletonEnumeration( final T element )
50 {
51 this.element = element;
52 }
53
54
55 /**
56 * Makes calls to hasMore to false even if we had more.
57 *
58 * @see javax.naming.NamingEnumeration#close()
59 */
60 public void close()
61 {
62 hasMore = false;
63 }
64
65
66 /**
67 * @see javax.naming.NamingEnumeration#hasMore()
68 */
69 public boolean hasMore()
70 {
71 return hasMore;
72 }
73
74
75 /**
76 * @see javax.naming.NamingEnumeration#next()
77 */
78 public T next()
79 {
80 if ( hasMore )
81 {
82 hasMore = false;
83 return element;
84 }
85
86 throw new NoSuchElementException();
87 }
88
89
90 /**
91 * @see java.util.Enumeration#hasMoreElements()
92 */
93 public boolean hasMoreElements()
94 {
95 return hasMore;
96 }
97
98
99 /**
100 * @see java.util.Enumeration#nextElement()
101 */
102 public T nextElement()
103 {
104 return next();
105 }
106 }