    001/*
    002 * Licensed to the Apache Software Foundation (ASF) under one or more
    003 * contributor license agreements.  See the NOTICE file distributed with
    004 * this work for additional information regarding copyright ownership.
    005 * The ASF licenses this file to You under the Apache License, Version 2.0
    006 * (the "License"); you may not use this file except in compliance with
    007 * the License.  You may obtain a copy of the License at
    008 *
    009 *      http://www.apache.org/licenses/LICENSE-2.0
    010 *
    011 * Unless required by applicable law or agreed to in writing, software
    012 * distributed under the License is distributed on an "AS IS" BASIS,
    013 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
    014 * See the License for the specific language governing permissions and
    015 * limitations under the License.
    016 */
    017package org.apache.commons.collections4;
    018
    019/**
    020 * Defines an iterator that operates over an ordered <code>Map</code>.
    021 * <p>
    022 * This iterator allows both forward and reverse iteration through the map.
    023 *
    024 * @param <K> the type of the keys in the map
    025 * @param <V> the type of the values in the map
    026 * @since 3.0
    027 */
    028public interface OrderedMapIterator<K, V> extends MapIterator<K, V>, OrderedIterator<K> {
    029
    030    /**
    031     * Checks to see if there is a previous entry that can be iterated to.
    032     *
    033     * @return <code>true</code> if the iterator has a previous element
    034     */
    035    @Override
    036    boolean hasPrevious();
    037
    038    /**
    039     * Gets the previous <em>key</em> from the <code>Map</code>.
    040     *
    041     * @return the previous key in the iteration
    042     * @throws java.util.NoSuchElementException if the iteration is finished
    043     */
    044    @Override
    045    K previous();
    046
    047}