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