org.apache.commons.collections4.map.MultiKeyMap Maven / Gradle / Ivy
/*
* 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 Map implementation that uses multiple keys to map the value.
*
* 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 get, containsKey, put and
* remove for individual keys which operate without extra object creation.
*
* The additional methods are the main interface of this map.
* As such, you will not normally hold this map in a variable of type Map.
*
* The normal map methods take in and return a {@link MultiKey}.
* If you try to use put() with any other object type a
* ClassCastException is thrown. If you try to use null as
* the key in put() a NullPointerException is thrown.
*
* This map is implemented as a decorator of a AbstractHashedMap which
* enables extra behaviour to be added easily.
*
* MultiKeyMap.decorate(new LinkedMap()) creates an ordered map.
* MultiKeyMap.decorate(new LRUMap()) creates an least recently used map.
* MultiKeyMap.decorate(new ReferenceMap()) creates a garbage collector sensitive map.
*
* Note that IdentityMap and ReferenceIdentityMap are unsuitable
* for use as the key comparison would work on the whole MultiKey, not the elements within.
*
* As an example, consider a least recently used cache that uses a String airline code
* and a Locale to lookup the airline's name:
*
* 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;
* }
*
*
* Note that MultiKeyMap is not synchronized and is not thread-safe.
* 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.
*
* @param the type of the keys in this map
* @param the type of the values in this map
* @since 3.1
*/
public class MultiKeyMap extends AbstractMapDecorator, 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 the key type
* @param the value type
* @param map the map to decorate, not null
* @return a new multi key map
* @throws NullPointerException if map is null
* @throws IllegalArgumentException if the map is not empty
* @since 4.0
*/
public static MultiKeyMap multiKeyMap(final AbstractHashedMap, V> map) {
if (map == null) {
throw new NullPointerException("Map must not be null");
}
if (map.size() > 0) {
throw new IllegalArgumentException("Map must be empty");
}
return new MultiKeyMap<>(map);
}
//-----------------------------------------------------------------------
/**
* Constructs a new MultiKeyMap that decorates a HashedMap.
*/
public MultiKeyMap() {
this(new HashedMap, 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, 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, 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, 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, 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<>(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, V> entry = decorated().data[index];
AbstractHashedMap.HashEntry, 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, V> entry,
final Object key1, final Object key2) {
final MultiKey multi = entry.getKey();
return
multi.size() == 2 &&
(key1 == multi.getKey(0) || key1 != null && key1.equals(multi.getKey(0))) &&
(key2 == multi.getKey(1) || key2 != 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, 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, 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, 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<>(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, V> entry = decorated().data[index];
AbstractHashedMap.HashEntry, 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, V> entry,
final Object key1, final Object key2, final Object key3) {
final MultiKey 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, 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, 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, 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<>(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, V> entry = decorated().data[index];
AbstractHashedMap.HashEntry, 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, V> entry,
final Object key1, final Object key2, final Object key3, final Object key4) {
final MultiKey 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, 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, 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, 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<>(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, V> entry = decorated().data[index];
AbstractHashedMap.HashEntry, 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, V> entry,
final Object key1, final Object key2, final Object key3, final Object key4, final Object key5) {
final MultiKey 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.
*
* This method removes all the mappings where the MultiKey
* 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, V> it = mapIterator();
while (it.hasNext()) {
final MultiKey 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.
*
* This method removes all the mappings where the MultiKey
* 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, V> it = mapIterator();
while (it.hasNext()) {
final MultiKey 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.
*
* This method removes all the mappings where the MultiKey
* 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, V> it = mapIterator();
while (it.hasNext()) {
final MultiKey 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.
*
* This method removes all the mappings where the MultiKey
* 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, V> it = mapIterator();
while (it.hasNext()) {
final MultiKey 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 clone() {
try {
return (MultiKeyMap) 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 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 V> mapToCopy) {
for (final MultiKey key : mapToCopy.keySet()) {
checkKey(key);
}
super.putAll(mapToCopy);
}
//-----------------------------------------------------------------------
@Override
public MapIterator, V> mapIterator() {
return decorated().mapIterator();
}
/**
* {@inheritDoc}
*/
@Override
protected AbstractHashedMap, V> decorated() {
return (AbstractHashedMap, V>) super.decorated();
}
//-----------------------------------------------------------------------
/**
* Write the map out using a custom routine.
*
* @param out the output stream
* @throws IOException if an error occurs while writing to the stream
*/
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 if an error occurs while reading from the stream
* @throws ClassNotFoundException if an object read from the stream can not be loaded
*/
@SuppressWarnings("unchecked")
private void readObject(final ObjectInputStream in) throws IOException, ClassNotFoundException {
in.defaultReadObject();
map = (Map, V>) in.readObject();
}
}