| /* |
| * Licensed to the Apache Software Foundation (ASF) under one or more |
| * contributor license agreements. See the NOTICE file distributed with |
| * this work for additional information regarding copyright ownership. |
| * The ASF licenses this file to You under the Apache License, Version 2.0 |
| * (the "License"); you may not use this file except in compliance with |
| * the License. You may obtain a copy of the License at |
| * |
| * http://www.apache.org/licenses/LICENSE-2.0 |
| * |
| * Unless required by applicable law or agreed to in writing, software |
| * distributed under the License is distributed on an "AS IS" BASIS, |
| * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| * See the License for the specific language governing permissions and |
| * limitations under the License. |
| */ |
| |
| package java.util; |
| |
| |
| /** |
| * A {@code Map} is a data structure consisting of a set of keys and values |
| * in which each key is mapped to a single value. The class of the objects |
| * used as keys is declared when the {@code Map} is declared, as is the |
| * class of the corresponding values. |
| * <p> |
| * A {@code Map} provides helper methods to iterate through all of the |
| * keys contained in it, as well as various methods to access and update |
| * the key/value pairs. |
| */ |
| public interface Map<K,V> { |
| |
| /** |
| * {@code Map.Entry} is a key/value mapping contained in a {@code Map}. |
| */ |
| public static interface Entry<K,V> { |
| /** |
| * Compares the specified object to this {@code Map.Entry} and returns if they |
| * are equal. To be equal, the object must be an instance of {@code Map.Entry} and have the |
| * same key and value. |
| * |
| * @param object |
| * the {@code Object} to compare with this {@code Object}. |
| * @return {@code true} if the specified {@code Object} is equal to this |
| * {@code Map.Entry}, {@code false} otherwise. |
| * @see #hashCode() |
| */ |
| public boolean equals(Object object); |
| |
| /** |
| * Returns the key. |
| * |
| * @return the key |
| */ |
| public K getKey(); |
| |
| /** |
| * Returns the value. |
| * |
| * @return the value |
| */ |
| public V getValue(); |
| |
| /** |
| * Returns an integer hash code for the receiver. {@code Object} which are |
| * equal return the same value for this method. |
| * |
| * @return the receiver's hash code. |
| * @see #equals(Object) |
| */ |
| public int hashCode(); |
| |
| /** |
| * Sets the value of this entry to the specified value, replacing any |
| * existing value. |
| * |
| * @param object |
| * the new value to set. |
| * @return object the replaced value of this entry. |
| */ |
| public V setValue(V object); |
| }; |
| |
| /** |
| * Removes all elements from this {@code Map}, leaving it empty. |
| * |
| * @throws UnsupportedOperationException |
| * if removing elements from this {@code Map} is not supported. |
| * @see #isEmpty() |
| * @see #size() |
| */ |
| public void clear(); |
| |
| /** |
| * Returns whether this {@code Map} contains the specified key. |
| * |
| * @param key |
| * the key to search for. |
| * @return {@code true} if this map contains the specified key, |
| * {@code false} otherwise. |
| */ |
| public boolean containsKey(Object key); |
| |
| /** |
| * Returns whether this {@code Map} contains the specified value. |
| * |
| * @param value |
| * the value to search for. |
| * @return {@code true} if this map contains the specified value, |
| * {@code false} otherwise. |
| */ |
| public boolean containsValue(Object value); |
| |
| /** |
| * Returns a {@code Set} containing all of the mappings in this {@code Map}. Each mapping is |
| * an instance of {@link Map.Entry}. As the {@code Set} is backed by this {@code Map}, |
| * changes in one will be reflected in the other. |
| * |
| * @return a set of the mappings |
| */ |
| public Set<Map.Entry<K,V>> entrySet(); |
| |
| /** |
| * Compares the argument to the receiver, and returns {@code true} if the |
| * specified object is a {@code Map} and both {@code Map}s contain the same mappings. |
| * |
| * @param object |
| * the {@code Object} to compare with this {@code Object}. |
| * @return boolean {@code true} if the {@code Object} is the same as this {@code Object} |
| * {@code false} if it is different from this {@code Object}. |
| * @see #hashCode() |
| * @see #entrySet() |
| */ |
| public boolean equals(Object object); |
| |
| /** |
| * Returns the value of the mapping with the specified key. |
| * |
| * @param key |
| * the key. |
| * @return the value of the mapping with the specified key, or {@code null} |
| * if no mapping for the specified key is found. |
| */ |
| public V get(Object key); |
| |
| /** |
| * Returns an integer hash code for the receiver. {@code Object}s which are equal |
| * return the same value for this method. |
| * |
| * @return the receiver's hash. |
| * @see #equals(Object) |
| */ |
| public int hashCode(); |
| |
| /** |
| * Returns whether this map is empty. |
| * |
| * @return {@code true} if this map has no elements, {@code false} |
| * otherwise. |
| * @see #size() |
| */ |
| public boolean isEmpty(); |
| |
| /** |
| * Returns a set of the keys contained in this {@code Map}. The {@code Set} is backed by |
| * this {@code Map} so changes to one are reflected by the other. The {@code Set} does not |
| * support adding. |
| * |
| * @return a set of the keys. |
| */ |
| public Set<K> keySet(); |
| |
| /** |
| * Maps the specified key to the specified value. |
| * |
| * @param key |
| * the key. |
| * @param value |
| * the value. |
| * @return the value of any previous mapping with the specified key or |
| * {@code null} if there was no mapping. |
| * @throws UnsupportedOperationException |
| * if adding to this {@code Map} is not supported. |
| * @throws ClassCastException |
| * if the class of the key or value is inappropriate for |
| * this {@code Map}. |
| * @throws IllegalArgumentException |
| * if the key or value cannot be added to this {@code Map}. |
| * @throws NullPointerException |
| * if the key or value is {@code null} and this {@code Map} does |
| * not support {@code null} keys or values. |
| */ |
| public V put(K key, V value); |
| |
| /** |
| * Copies every mapping in the specified {@code Map} to this {@code Map}. |
| * |
| * @param map |
| * the {@code Map} to copy mappings from. |
| * @throws UnsupportedOperationException |
| * if adding to this {@code Map} is not supported. |
| * @throws ClassCastException |
| * if the class of a key or a value of the specified {@code Map} is |
| * inappropriate for this {@code Map}. |
| * @throws IllegalArgumentException |
| * if a key or value cannot be added to this {@code Map}. |
| * @throws NullPointerException |
| * if a key or value is {@code null} and this {@code Map} does not |
| * support {@code null} keys or values. |
| */ |
| public void putAll(Map<? extends K,? extends V> map); |
| |
| /** |
| * Removes a mapping with the specified key from this {@code Map}. |
| * |
| * @param key |
| * the key of the mapping to remove. |
| * @return the value of the removed mapping or {@code null} if no mapping |
| * for the specified key was found. |
| * @throws UnsupportedOperationException |
| * if removing from this {@code Map} is not supported. |
| */ |
| public V remove(Object key); |
| |
| /** |
| * Returns the number of mappings in this {@code Map}. |
| * |
| * @return the number of mappings in this {@code Map}. |
| */ |
| public int size(); |
| |
| /** |
| * Returns a {@code Collection} of the values contained in this {@code Map}. The {@code Collection} |
| * is backed by this {@code Map} so changes to one are reflected by the other. The |
| * {@code Collection} supports {@link Collection#remove}, {@link Collection#removeAll}, |
| * {@link Collection#retainAll}, and {@link Collection#clear} operations, |
| * and it does not support {@link Collection#add} or {@link Collection#addAll} operations. |
| * <p> |
| * This method returns a {@code Collection} which is the subclass of |
| * {@link AbstractCollection}. The {@link AbstractCollection#iterator} method of this subclass returns a |
| * "wrapper object" over the iterator of this {@code Map}'s {@link #entrySet()}. The {@link AbstractCollection#size} method |
| * wraps this {@code Map}'s {@link #size} method and the {@link AbstractCollection#contains} method wraps this {@code Map}'s |
| * {@link #containsValue} method. |
| * <p> |
| * The collection is created when this method is called at first time and |
| * returned in response to all subsequent calls. This method may return |
| * different Collection when multiple calls to this method, since it has no |
| * synchronization performed. |
| * |
| * @return a collection of the values contained in this map. |
| */ |
| public Collection<V> values(); |
| } |