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 * https://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
18 package org.apache.commons.collections4;
19
20 /**
21 * Defines an iterator that operates over an ordered {@code Map}.
22 * <p>
23 * This iterator allows both forward and reverse iteration through the map.
24 * </p>
25 *
26 * @param <K> The type of the keys in the map
27 * @param <V> The type of the values in the map
28 * @since 3.0
29 */
30 public interface OrderedMapIterator<K, V> extends MapIterator<K, V>, OrderedIterator<K> {
31
32 /**
33 * Checks to see if there is a previous entry that can be iterated to.
34 *
35 * @return {@code true} if the iterator has a previous element.
36 */
37 @Override
38 boolean hasPrevious();
39
40 /**
41 * Gets the previous <em>key</em> from the {@code Map}.
42 *
43 * @return The previous key in the iteration.
44 * @throws java.util.NoSuchElementException if the iteration is finished.
45 */
46 @Override
47 K previous();
48 }