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 *      https://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 */
017
018package org.apache.commons.collections4;
019
020import java.util.Map;
021
022/**
023 * The "write" subset of the {@link Map} interface.
024 * <p>
025 * NOTE: in the original {@link Map} interface, {@link Map#put(Object, Object)} is known to have the same return type as {@link Map#get(Object)}, namely
026 * {@code V}. {@link Put} makes no assumptions in this regard (there is no association with, nor even knowledge of, a "reading" interface) and thus defines
027 * {@link #put(Object, Object)} as returning {@link Object}.
028 * </p>
029 *
030 * @param <K> The type of the keys in this map.
031 * @param <V> The type of the values in this map.
032 * @since 4.0
033 * @see Get
034 */
035public interface Put<K, V> {
036
037    /**
038     * Removes all of the mappings from this map.
039     *
040     * @see Map#clear()
041     */
042    void clear();
043
044    /**
045     * Associates the specified value with the specified key in this map.
046     * <p>
047     * Note that the return type is Object, rather than V as in the Map interface. See the class Javadoc for further info.
048     * </p>
049     *
050     * @param key   key with which the specified value is to be associated.
051     * @param value value to be associated with the specified key.
052     * @return The previous value associated with {@code key}, or {@code null} if there was no mapping for {@code key}. (A {@code null} return can also indicate
053     *         that the map previously associated {@code null} with {@code key}, if the implementation supports {@code null} values.)
054     * @see Map#put(Object, Object)
055     */
056    Object put(K key, V value);
057
058    /**
059     * Copies all of the mappings from the specified map to this map.
060     *
061     * @param t mappings to be stored in this map.
062     * @see Map#putAll(Map)
063     */
064    void putAll(Map<? extends K, ? extends V> t);
065}