Java tutorial
/* * 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 org.apache.commons.collections4.map; import java.io.IOException; import java.io.ObjectInputStream; import java.io.ObjectOutputStream; import java.io.Serializable; import java.util.Map; import org.apache.commons.collections4.MapIterator; import org.apache.commons.collections4.keyvalue.MultiKey; /** * A <code>Map</code> implementation that uses multiple keys to map the value. * <p> * This class is the most efficient way to uses multiple keys to map to a value. * The best way to use this class is via the additional map-style methods. * These provide <code>get</code>, <code>containsKey</code>, <code>put</code> and * <code>remove</code> for individual keys which operate without extra object creation. * <p> * The additional methods are the main interface of this map. * As such, you will not normally hold this map in a variable of type <code>Map</code>. * <p> * The normal map methods take in and return a {@link MultiKey}. * If you try to use <code>put()</code> with any other object type a * <code>ClassCastException</code> is thrown. If you try to use <code>null</code> as * the key in <code>put()</code> a <code>NullPointerException</code> is thrown. * <p> * This map is implemented as a decorator of a <code>AbstractHashedMap</code> which * enables extra behaviour to be added easily. * <ul> * <li><code>MultiKeyMap.decorate(new LinkedMap())</code> creates an ordered map. * <li><code>MultiKeyMap.decorate(new LRUMap())</code> creates an least recently used map. * <li><code>MultiKeyMap.decorate(new ReferenceMap())</code> creates a garbage collector sensitive map. * </ul> * Note that <code>IdentityMap</code> and <code>ReferenceIdentityMap</code> are unsuitable * for use as the key comparison would work on the whole MultiKey, not the elements within. * <p> * As an example, consider a least recently used cache that uses a String airline code * and a Locale to lookup the airline's name: * <pre> * private MultiKeyMap cache = MultiKeyMap.multiKeyMap(new LRUMap(50)); * * public String getAirlineName(String code, String locale) { * String name = (String) cache.get(code, locale); * if (name == null) { * name = getAirlineNameFromDB(code, locale); * cache.put(code, locale, name); * } * return name; * } * </pre> * <p> * <strong>Note that MultiKeyMap is not synchronized and is not thread-safe.</strong> * If you wish to use this map from multiple threads concurrently, you must use * appropriate synchronization. This class may throw exceptions when accessed * by concurrent threads without synchronization. * * @since 3.1 * @version $Id: MultiKeyMap.java 1543167 2013-11-18 21:21:32Z ggregory $ */ public class MultiKeyMap<K, V> extends AbstractMapDecorator<MultiKey<? extends K>, V> implements Serializable, Cloneable { /** Serialisation version */ private static final long serialVersionUID = -1788199231038721040L; //----------------------------------------------------------------------- /** * Decorates the specified map to add the MultiKeyMap API and fast query. * The map must not be null and must be empty. * * @param <K> the key type * @param <V> the value type * @param map the map to decorate, not null * @return a new multi key map * @throws IllegalArgumentException if the map is null or not empty * @since 4.0 */ public static <K, V> MultiKeyMap<K, V> multiKeyMap(final AbstractHashedMap<MultiKey<? extends K>, V> map) { if (map == null) { throw new IllegalArgumentException("Map must not be null"); } if (map.size() > 0) { throw new IllegalArgumentException("Map must be empty"); } return new MultiKeyMap<K, V>(map); } //----------------------------------------------------------------------- /** * Constructs a new MultiKeyMap that decorates a <code>HashedMap</code>. */ public MultiKeyMap() { this(new HashedMap<MultiKey<? extends K>, V>()); } /** * Constructor that decorates the specified map and is called from * {@link #multiKeyMap(AbstractHashedMap)}. * The map must not be null and should be empty or only contain valid keys. * This constructor performs no validation. * * @param map the map to decorate */ protected MultiKeyMap(final AbstractHashedMap<MultiKey<? extends K>, V> map) { super(map); this.map = map; } //----------------------------------------------------------------------- /** * Gets the value mapped to the specified multi-key. * * @param key1 the first key * @param key2 the second key * @return the mapped value, null if no match */ public V get(final Object key1, final Object key2) { final int hashCode = hash(key1, key2); AbstractHashedMap.HashEntry<MultiKey<? extends K>, V> entry = decorated().data[decorated() .hashIndex(hashCode, decorated().data.length)]; while (entry != null) { if (entry.hashCode == hashCode && isEqualKey(entry, key1, key2)) { return entry.getValue(); } entry = entry.next; } return null; } /** * Checks whether the map contains the specified multi-key. * * @param key1 the first key * @param key2 the second key * @return true if the map contains the key */ public boolean containsKey(final Object key1, final Object key2) { final int hashCode = hash(key1, key2); AbstractHashedMap.HashEntry<MultiKey<? extends K>, V> entry = decorated().data[decorated() .hashIndex(hashCode, decorated().data.length)]; while (entry != null) { if (entry.hashCode == hashCode && isEqualKey(entry, key1, key2)) { return true; } entry = entry.next; } return false; } /** * Stores the value against the specified multi-key. * * @param key1 the first key * @param key2 the second key * @param value the value to store * @return the value previously mapped to this combined key, null if none */ public V put(final K key1, final K key2, final V value) { final int hashCode = hash(key1, key2); final int index = decorated().hashIndex(hashCode, decorated().data.length); AbstractHashedMap.HashEntry<MultiKey<? extends K>, V> entry = decorated().data[index]; while (entry != null) { if (entry.hashCode == hashCode && isEqualKey(entry, key1, key2)) { final V oldValue = entry.getValue(); decorated().updateEntry(entry, value); return oldValue; } entry = entry.next; } decorated().addMapping(index, hashCode, new MultiKey<K>(key1, key2), value); return null; } /** * Removes the specified multi-key from this map. * * @param key1 the first key * @param key2 the second key * @return the value mapped to the removed key, null if key not in map * @since 4.0 (previous name: remove(Object, Object)) */ public V removeMultiKey(final Object key1, final Object key2) { final int hashCode = hash(key1, key2); final int index = decorated().hashIndex(hashCode, decorated().data.length); AbstractHashedMap.HashEntry<MultiKey<? extends K>, V> entry = decorated().data[index]; AbstractHashedMap.HashEntry<MultiKey<? extends K>, V> previous = null; while (entry != null) { if (entry.hashCode == hashCode && isEqualKey(entry, key1, key2)) { final V oldValue = entry.getValue(); decorated().removeMapping(entry, index, previous); return oldValue; } previous = entry; entry = entry.next; } return null; } /** * Gets the hash code for the specified multi-key. * * @param key1 the first key * @param key2 the second key * @return the hash code */ protected int hash(final Object key1, final Object key2) { int h = 0; if (key1 != null) { h ^= key1.hashCode(); } if (key2 != null) { h ^= key2.hashCode(); } h += ~(h << 9); h ^= h >>> 14; h += h << 4; h ^= h >>> 10; return h; } /** * Is the key equal to the combined key. * * @param entry the entry to compare to * @param key1 the first key * @param key2 the second key * @return true if the key matches */ protected boolean isEqualKey(final AbstractHashedMap.HashEntry<MultiKey<? extends K>, V> entry, final Object key1, final Object key2) { final MultiKey<? extends K> multi = entry.getKey(); return multi.size() == 2 && (key1 == multi.getKey(0) || key1 != null && key1.equals(multi.getKey(0))) && (key2 == multi.getKey(1) || key1 != null && key2.equals(multi.getKey(1))); } //----------------------------------------------------------------------- /** * Gets the value mapped to the specified multi-key. * * @param key1 the first key * @param key2 the second key * @param key3 the third key * @return the mapped value, null if no match */ public V get(final Object key1, final Object key2, final Object key3) { final int hashCode = hash(key1, key2, key3); AbstractHashedMap.HashEntry<MultiKey<? extends K>, V> entry = decorated().data[decorated() .hashIndex(hashCode, decorated().data.length)]; while (entry != null) { if (entry.hashCode == hashCode && isEqualKey(entry, key1, key2, key3)) { return entry.getValue(); } entry = entry.next; } return null; } /** * Checks whether the map contains the specified multi-key. * * @param key1 the first key * @param key2 the second key * @param key3 the third key * @return true if the map contains the key */ public boolean containsKey(final Object key1, final Object key2, final Object key3) { final int hashCode = hash(key1, key2, key3); AbstractHashedMap.HashEntry<MultiKey<? extends K>, V> entry = decorated().data[decorated() .hashIndex(hashCode, decorated().data.length)]; while (entry != null) { if (entry.hashCode == hashCode && isEqualKey(entry, key1, key2, key3)) { return true; } entry = entry.next; } return false; } /** * Stores the value against the specified multi-key. * * @param key1 the first key * @param key2 the second key * @param key3 the third key * @param value the value to store * @return the value previously mapped to this combined key, null if none */ public V put(final K key1, final K key2, final K key3, final V value) { final int hashCode = hash(key1, key2, key3); final int index = decorated().hashIndex(hashCode, decorated().data.length); AbstractHashedMap.HashEntry<MultiKey<? extends K>, V> entry = decorated().data[index]; while (entry != null) { if (entry.hashCode == hashCode && isEqualKey(entry, key1, key2, key3)) { final V oldValue = entry.getValue(); decorated().updateEntry(entry, value); return oldValue; } entry = entry.next; } decorated().addMapping(index, hashCode, new MultiKey<K>(key1, key2, key3), value); return null; } /** * Removes the specified multi-key from this map. * * @param key1 the first key * @param key2 the second key * @param key3 the third key * @return the value mapped to the removed key, null if key not in map * @since 4.0 (previous name: remove(Object, Object, Object)) */ public V removeMultiKey(final Object key1, final Object key2, final Object key3) { final int hashCode = hash(key1, key2, key3); final int index = decorated().hashIndex(hashCode, decorated().data.length); AbstractHashedMap.HashEntry<MultiKey<? extends K>, V> entry = decorated().data[index]; AbstractHashedMap.HashEntry<MultiKey<? extends K>, V> previous = null; while (entry != null) { if (entry.hashCode == hashCode && isEqualKey(entry, key1, key2, key3)) { final V oldValue = entry.getValue(); decorated().removeMapping(entry, index, previous); return oldValue; } previous = entry; entry = entry.next; } return null; } /** * Gets the hash code for the specified multi-key. * * @param key1 the first key * @param key2 the second key * @param key3 the third key * @return the hash code */ protected int hash(final Object key1, final Object key2, final Object key3) { int h = 0; if (key1 != null) { h ^= key1.hashCode(); } if (key2 != null) { h ^= key2.hashCode(); } if (key3 != null) { h ^= key3.hashCode(); } h += ~(h << 9); h ^= h >>> 14; h += h << 4; h ^= h >>> 10; return h; } /** * Is the key equal to the combined key. * * @param entry the entry to compare to * @param key1 the first key * @param key2 the second key * @param key3 the third key * @return true if the key matches */ protected boolean isEqualKey(final AbstractHashedMap.HashEntry<MultiKey<? extends K>, V> entry, final Object key1, final Object key2, final Object key3) { final MultiKey<? extends K> multi = entry.getKey(); return multi.size() == 3 && (key1 == multi.getKey(0) || key1 != null && key1.equals(multi.getKey(0))) && (key2 == multi.getKey(1) || key2 != null && key2.equals(multi.getKey(1))) && (key3 == multi.getKey(2) || key3 != null && key3.equals(multi.getKey(2))); } //----------------------------------------------------------------------- /** * Gets the value mapped to the specified multi-key. * * @param key1 the first key * @param key2 the second key * @param key3 the third key * @param key4 the fourth key * @return the mapped value, null if no match */ public V get(final Object key1, final Object key2, final Object key3, final Object key4) { final int hashCode = hash(key1, key2, key3, key4); AbstractHashedMap.HashEntry<MultiKey<? extends K>, V> entry = decorated().data[decorated() .hashIndex(hashCode, decorated().data.length)]; while (entry != null) { if (entry.hashCode == hashCode && isEqualKey(entry, key1, key2, key3, key4)) { return entry.getValue(); } entry = entry.next; } return null; } /** * Checks whether the map contains the specified multi-key. * * @param key1 the first key * @param key2 the second key * @param key3 the third key * @param key4 the fourth key * @return true if the map contains the key */ public boolean containsKey(final Object key1, final Object key2, final Object key3, final Object key4) { final int hashCode = hash(key1, key2, key3, key4); AbstractHashedMap.HashEntry<MultiKey<? extends K>, V> entry = decorated().data[decorated() .hashIndex(hashCode, decorated().data.length)]; while (entry != null) { if (entry.hashCode == hashCode && isEqualKey(entry, key1, key2, key3, key4)) { return true; } entry = entry.next; } return false; } /** * Stores the value against the specified multi-key. * * @param key1 the first key * @param key2 the second key * @param key3 the third key * @param key4 the fourth key * @param value the value to store * @return the value previously mapped to this combined key, null if none */ public V put(final K key1, final K key2, final K key3, final K key4, final V value) { final int hashCode = hash(key1, key2, key3, key4); final int index = decorated().hashIndex(hashCode, decorated().data.length); AbstractHashedMap.HashEntry<MultiKey<? extends K>, V> entry = decorated().data[index]; while (entry != null) { if (entry.hashCode == hashCode && isEqualKey(entry, key1, key2, key3, key4)) { final V oldValue = entry.getValue(); decorated().updateEntry(entry, value); return oldValue; } entry = entry.next; } decorated().addMapping(index, hashCode, new MultiKey<K>(key1, key2, key3, key4), value); return null; } /** * Removes the specified multi-key from this map. * * @param key1 the first key * @param key2 the second key * @param key3 the third key * @param key4 the fourth key * @return the value mapped to the removed key, null if key not in map * @since 4.0 (previous name: remove(Object, Object, Object, Object)) */ public V removeMultiKey(final Object key1, final Object key2, final Object key3, final Object key4) { final int hashCode = hash(key1, key2, key3, key4); final int index = decorated().hashIndex(hashCode, decorated().data.length); AbstractHashedMap.HashEntry<MultiKey<? extends K>, V> entry = decorated().data[index]; AbstractHashedMap.HashEntry<MultiKey<? extends K>, V> previous = null; while (entry != null) { if (entry.hashCode == hashCode && isEqualKey(entry, key1, key2, key3, key4)) { final V oldValue = entry.getValue(); decorated().removeMapping(entry, index, previous); return oldValue; } previous = entry; entry = entry.next; } return null; } /** * Gets the hash code for the specified multi-key. * * @param key1 the first key * @param key2 the second key * @param key3 the third key * @param key4 the fourth key * @return the hash code */ protected int hash(final Object key1, final Object key2, final Object key3, final Object key4) { int h = 0; if (key1 != null) { h ^= key1.hashCode(); } if (key2 != null) { h ^= key2.hashCode(); } if (key3 != null) { h ^= key3.hashCode(); } if (key4 != null) { h ^= key4.hashCode(); } h += ~(h << 9); h ^= h >>> 14; h += h << 4; h ^= h >>> 10; return h; } /** * Is the key equal to the combined key. * * @param entry the entry to compare to * @param key1 the first key * @param key2 the second key * @param key3 the third key * @param key4 the fourth key * @return true if the key matches */ protected boolean isEqualKey(final AbstractHashedMap.HashEntry<MultiKey<? extends K>, V> entry, final Object key1, final Object key2, final Object key3, final Object key4) { final MultiKey<? extends K> multi = entry.getKey(); return multi.size() == 4 && (key1 == multi.getKey(0) || key1 != null && key1.equals(multi.getKey(0))) && (key2 == multi.getKey(1) || key2 != null && key2.equals(multi.getKey(1))) && (key3 == multi.getKey(2) || key3 != null && key3.equals(multi.getKey(2))) && (key4 == multi.getKey(3) || key4 != null && key4.equals(multi.getKey(3))); } //----------------------------------------------------------------------- /** * Gets the value mapped to the specified multi-key. * * @param key1 the first key * @param key2 the second key * @param key3 the third key * @param key4 the fourth key * @param key5 the fifth key * @return the mapped value, null if no match */ public V get(final Object key1, final Object key2, final Object key3, final Object key4, final Object key5) { final int hashCode = hash(key1, key2, key3, key4, key5); AbstractHashedMap.HashEntry<MultiKey<? extends K>, V> entry = decorated().data[decorated() .hashIndex(hashCode, decorated().data.length)]; while (entry != null) { if (entry.hashCode == hashCode && isEqualKey(entry, key1, key2, key3, key4, key5)) { return entry.getValue(); } entry = entry.next; } return null; } /** * Checks whether the map contains the specified multi-key. * * @param key1 the first key * @param key2 the second key * @param key3 the third key * @param key4 the fourth key * @param key5 the fifth key * @return true if the map contains the key */ public boolean containsKey(final Object key1, final Object key2, final Object key3, final Object key4, final Object key5) { final int hashCode = hash(key1, key2, key3, key4, key5); AbstractHashedMap.HashEntry<MultiKey<? extends K>, V> entry = decorated().data[decorated() .hashIndex(hashCode, decorated().data.length)]; while (entry != null) { if (entry.hashCode == hashCode && isEqualKey(entry, key1, key2, key3, key4, key5)) { return true; } entry = entry.next; } return false; } /** * Stores the value against the specified multi-key. * * @param key1 the first key * @param key2 the second key * @param key3 the third key * @param key4 the fourth key * @param key5 the fifth key * @param value the value to store * @return the value previously mapped to this combined key, null if none */ public V put(final K key1, final K key2, final K key3, final K key4, final K key5, final V value) { final int hashCode = hash(key1, key2, key3, key4, key5); final int index = decorated().hashIndex(hashCode, decorated().data.length); AbstractHashedMap.HashEntry<MultiKey<? extends K>, V> entry = decorated().data[index]; while (entry != null) { if (entry.hashCode == hashCode && isEqualKey(entry, key1, key2, key3, key4, key5)) { final V oldValue = entry.getValue(); decorated().updateEntry(entry, value); return oldValue; } entry = entry.next; } decorated().addMapping(index, hashCode, new MultiKey<K>(key1, key2, key3, key4, key5), value); return null; } /** * Removes the specified multi-key from this map. * * @param key1 the first key * @param key2 the second key * @param key3 the third key * @param key4 the fourth key * @param key5 the fifth key * @return the value mapped to the removed key, null if key not in map * @since 4.0 (previous name: remove(Object, Object, Object, Object, Object)) */ public V removeMultiKey(final Object key1, final Object key2, final Object key3, final Object key4, final Object key5) { final int hashCode = hash(key1, key2, key3, key4, key5); final int index = decorated().hashIndex(hashCode, decorated().data.length); AbstractHashedMap.HashEntry<MultiKey<? extends K>, V> entry = decorated().data[index]; AbstractHashedMap.HashEntry<MultiKey<? extends K>, V> previous = null; while (entry != null) { if (entry.hashCode == hashCode && isEqualKey(entry, key1, key2, key3, key4, key5)) { final V oldValue = entry.getValue(); decorated().removeMapping(entry, index, previous); return oldValue; } previous = entry; entry = entry.next; } return null; } /** * Gets the hash code for the specified multi-key. * * @param key1 the first key * @param key2 the second key * @param key3 the third key * @param key4 the fourth key * @param key5 the fifth key * @return the hash code */ protected int hash(final Object key1, final Object key2, final Object key3, final Object key4, final Object key5) { int h = 0; if (key1 != null) { h ^= key1.hashCode(); } if (key2 != null) { h ^= key2.hashCode(); } if (key3 != null) { h ^= key3.hashCode(); } if (key4 != null) { h ^= key4.hashCode(); } if (key5 != null) { h ^= key5.hashCode(); } h += ~(h << 9); h ^= h >>> 14; h += h << 4; h ^= h >>> 10; return h; } /** * Is the key equal to the combined key. * * @param entry the entry to compare to * @param key1 the first key * @param key2 the second key * @param key3 the third key * @param key4 the fourth key * @param key5 the fifth key * @return true if the key matches */ protected boolean isEqualKey(final AbstractHashedMap.HashEntry<MultiKey<? extends K>, V> entry, final Object key1, final Object key2, final Object key3, final Object key4, final Object key5) { final MultiKey<? extends K> multi = entry.getKey(); return multi.size() == 5 && (key1 == multi.getKey(0) || key1 != null && key1.equals(multi.getKey(0))) && (key2 == multi.getKey(1) || key2 != null && key2.equals(multi.getKey(1))) && (key3 == multi.getKey(2) || key3 != null && key3.equals(multi.getKey(2))) && (key4 == multi.getKey(3) || key4 != null && key4.equals(multi.getKey(3))) && (key5 == multi.getKey(4) || key5 != null && key5.equals(multi.getKey(4))); } //----------------------------------------------------------------------- /** * Removes all mappings where the first key is that specified. * <p> * This method removes all the mappings where the <code>MultiKey</code> * has one or more keys, and the first matches that specified. * * @param key1 the first key * @return true if any elements were removed */ public boolean removeAll(final Object key1) { boolean modified = false; final MapIterator<MultiKey<? extends K>, V> it = mapIterator(); while (it.hasNext()) { final MultiKey<? extends K> multi = it.next(); if (multi.size() >= 1 && (key1 == null ? multi.getKey(0) == null : key1.equals(multi.getKey(0)))) { it.remove(); modified = true; } } return modified; } /** * Removes all mappings where the first two keys are those specified. * <p> * This method removes all the mappings where the <code>MultiKey</code> * has two or more keys, and the first two match those specified. * * @param key1 the first key * @param key2 the second key * @return true if any elements were removed */ public boolean removeAll(final Object key1, final Object key2) { boolean modified = false; final MapIterator<MultiKey<? extends K>, V> it = mapIterator(); while (it.hasNext()) { final MultiKey<? extends K> multi = it.next(); if (multi.size() >= 2 && (key1 == null ? multi.getKey(0) == null : key1.equals(multi.getKey(0))) && (key2 == null ? multi.getKey(1) == null : key2.equals(multi.getKey(1)))) { it.remove(); modified = true; } } return modified; } /** * Removes all mappings where the first three keys are those specified. * <p> * This method removes all the mappings where the <code>MultiKey</code> * has three or more keys, and the first three match those specified. * * @param key1 the first key * @param key2 the second key * @param key3 the third key * @return true if any elements were removed */ public boolean removeAll(final Object key1, final Object key2, final Object key3) { boolean modified = false; final MapIterator<MultiKey<? extends K>, V> it = mapIterator(); while (it.hasNext()) { final MultiKey<? extends K> multi = it.next(); if (multi.size() >= 3 && (key1 == null ? multi.getKey(0) == null : key1.equals(multi.getKey(0))) && (key2 == null ? multi.getKey(1) == null : key2.equals(multi.getKey(1))) && (key3 == null ? multi.getKey(2) == null : key3.equals(multi.getKey(2)))) { it.remove(); modified = true; } } return modified; } /** * Removes all mappings where the first four keys are those specified. * <p> * This method removes all the mappings where the <code>MultiKey</code> * has four or more keys, and the first four match those specified. * * @param key1 the first key * @param key2 the second key * @param key3 the third key * @param key4 the fourth key * @return true if any elements were removed */ public boolean removeAll(final Object key1, final Object key2, final Object key3, final Object key4) { boolean modified = false; final MapIterator<MultiKey<? extends K>, V> it = mapIterator(); while (it.hasNext()) { final MultiKey<? extends K> multi = it.next(); if (multi.size() >= 4 && (key1 == null ? multi.getKey(0) == null : key1.equals(multi.getKey(0))) && (key2 == null ? multi.getKey(1) == null : key2.equals(multi.getKey(1))) && (key3 == null ? multi.getKey(2) == null : key3.equals(multi.getKey(2))) && (key4 == null ? multi.getKey(3) == null : key4.equals(multi.getKey(3)))) { it.remove(); modified = true; } } return modified; } //----------------------------------------------------------------------- /** * Check to ensure that input keys are valid MultiKey objects. * * @param key the key to check */ protected void checkKey(final MultiKey<?> key) { if (key == null) { throw new NullPointerException("Key must not be null"); } } /** * Clones the map without cloning the keys or values. * * @return a shallow clone */ @SuppressWarnings("unchecked") @Override public MultiKeyMap<K, V> clone() { try { return (MultiKeyMap<K, V>) super.clone(); } catch (final CloneNotSupportedException e) { throw new InternalError(); } } /** * Puts the key and value into the map, where the key must be a non-null * MultiKey object. * * @param key the non-null MultiKey object * @param value the value to store * @return the previous value for the key * @throws NullPointerException if the key is null * @throws ClassCastException if the key is not a MultiKey */ @Override public V put(final MultiKey<? extends K> key, final V value) { checkKey(key); return super.put(key, value); } /** * Copies all of the keys and values from the specified map to this map. * Each key must be non-null and a MultiKey object. * * @param mapToCopy to this map * @throws NullPointerException if the mapToCopy or any key within is null * @throws ClassCastException if any key in mapToCopy is not a MultiKey */ @Override public void putAll(final Map<? extends MultiKey<? extends K>, ? extends V> mapToCopy) { for (final MultiKey<? extends K> key : mapToCopy.keySet()) { checkKey(key); } super.putAll(mapToCopy); } //----------------------------------------------------------------------- @Override public MapIterator<MultiKey<? extends K>, V> mapIterator() { return decorated().mapIterator(); } /** * {@inheritDoc} */ @Override protected AbstractHashedMap<MultiKey<? extends K>, V> decorated() { return (AbstractHashedMap<MultiKey<? extends K>, V>) super.decorated(); } //----------------------------------------------------------------------- /** * Write the map out using a custom routine. * * @param out the output stream * @throws IOException */ private void writeObject(final ObjectOutputStream out) throws IOException { out.defaultWriteObject(); out.writeObject(map); } /** * Read the map in using a custom routine. * * @param in the input stream * @throws IOException * @throws ClassNotFoundException */ @SuppressWarnings("unchecked") private void readObject(final ObjectInputStream in) throws IOException, ClassNotFoundException { in.defaultReadObject(); map = (Map<MultiKey<? extends K>, V>) in.readObject(); } }