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.commons.collections4.iterators;
18
19 import org.apache.commons.collections4.MapIterator;
20
21 /**
22 * Provides an implementation of an empty map iterator.
23 *
24 * @param <K> the type of keys
25 * @param <V> the type of mapped values
26 * @since 3.1
27 */
28 public class EmptyMapIterator<K, V> extends AbstractEmptyMapIterator<K, V> implements
29 MapIterator<K, V> {
30
31 /**
32 * Singleton instance of the iterator.
33 * @since 3.1
34 */
35 @SuppressWarnings("rawtypes")
36 public static final MapIterator INSTANCE = new EmptyMapIterator<>();
37
38 /**
39 * Gets a typed instance of the iterator.
40 * @param <K> the key type
41 * @param <V> the value type
42 * @return {@link MapIterator}<K, V>
43 */
44 public static <K, V> MapIterator<K, V> emptyMapIterator() {
45 return INSTANCE;
46 }
47
48 /**
49 * Constructs a new instance.
50 */
51 protected EmptyMapIterator() {
52 }
53
54 }