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.iterators;
018
019import org.apache.commons.collections4.MapIterator;
020import org.apache.commons.collections4.ResettableIterator;
021
022/**
023 * Provides an implementation of an empty map iterator.
024 *
025 * @since 3.1
026 */
027public class EmptyMapIterator<K, V> extends AbstractEmptyMapIterator<K, V> implements
028        MapIterator<K, V>, ResettableIterator<K> {
029
030    /**
031     * Singleton instance of the iterator.
032     * @since 3.1
033     */
034    @SuppressWarnings("rawtypes")
035    public static final MapIterator INSTANCE = new EmptyMapIterator<>();
036
037    /**
038     * Get a typed instance of the iterator.
039     * @param <K> the key type
040     * @param <V> the value type
041     * @return {@link MapIterator}&lt;K, V&gt;
042     */
043    @SuppressWarnings("unchecked")
044    public static <K, V> MapIterator<K, V> emptyMapIterator() {
045        return INSTANCE;
046    }
047
048    /**
049     * Constructor.
050     */
051    protected EmptyMapIterator() {
052        super();
053    }
054
055}