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.logging.log4j.util; 18 19 /** 20 * An extension of {@code ReadOnlyStringMap} that imposes a total ordering on its keys. 21 * The map is ordered according to the natural ordering of its keys. This order is reflected when 22 * {@link #forEach(BiConsumer) consuming} the key-value pairs with a {@link BiConsumer} or a {@link TriConsumer}. 23 * <p> 24 * This interface views all key-value pairs as a sequence ordered by key, and allows 25 * keys and values to be accessed by their index in the sequence. 26 * </p> 27 * 28 * @see ReadOnlyStringMap 29 * @since 2.8 30 */ 31 public interface IndexedReadOnlyStringMap extends ReadOnlyStringMap { 32 33 /** 34 * Viewing all key-value pairs as a sequence sorted by key, this method returns the key at the specified index, 35 * or {@code null} if the specified index is less than zero or greater or equal to the size of this collection. 36 * 37 * @param index the index of the key to return 38 * @return the key at the specified index or {@code null} 39 */ 40 String getKeyAt(final int index); 41 42 /** 43 * Viewing all key-value pairs as a sequence sorted by key, this method returns the value at the specified index, 44 * or {@code null} if the specified index is less than zero or greater or equal to the size of this collection. 45 * 46 * @param index the index of the value to return 47 * @return the value at the specified index or {@code null} 48 */ 49 <V> V getValueAt(final int index); 50 51 /** 52 * Viewing all key-value pairs as a sequence sorted by key, this method returns the index of the specified key in 53 * that sequence. If the specified key is not found, this method returns {@code (-(insertion point) - 1)}. 54 * 55 * @param key the key whose index in the ordered sequence of keys to return 56 * @return the index of the specified key or {@code (-(insertion point) - 1)} if the key is not found. 57 * The insertion point is defined as the point at which the key would be inserted into the array: 58 * the index of the first element in the range greater than the key, or {@code size()} if all elements 59 * are less than the specified key. Note that this guarantees that the return value will be >= 0 60 * if and only if the key is found. 61 */ 62 int indexOfKey(final String key); 63 }