org.apache.commons.collections4.multimap.HashSetValuedHashMap Maven / Gradle / Ivy
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/*
* 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.multimap;
import java.io.IOException;
import java.io.ObjectInputStream;
import java.io.ObjectOutputStream;
import java.io.Serializable;
import java.util.HashMap;
import java.util.HashSet;
import java.util.Map;
import org.apache.commons.collections4.MultiValuedMap;
/**
* Implements a {@code SetValuedMap}, using a {@link HashMap} to provide data
* storage and {@link HashSet}s as value collections. This is the standard
* implementation of a SetValuedMap.
*
* Note that HashSetValuedHashMap 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.
*
* @since 4.1
* @version $Id: HashSetValuedHashMap.java 1715492 2015-11-21 10:09:31Z tn $
*/
public class HashSetValuedHashMap extends AbstractSetValuedMap
implements Serializable {
/** Serialization Version */
private static final long serialVersionUID = 20151118L;
/**
* The initial map capacity used when none specified in constructor.
*/
private static final int DEFAULT_INITIAL_MAP_CAPACITY = 16;
/**
* The initial set capacity when using none specified in constructor.
*/
private static final int DEFAULT_INITIAL_SET_CAPACITY = 3;
/**
* The initial list capacity when creating a new value collection.
*/
private final int initialSetCapacity;
/**
* Creates an empty HashSetValuedHashMap with the default initial
* map capacity (16) and the default initial set capacity (3).
*/
public HashSetValuedHashMap() {
this(DEFAULT_INITIAL_MAP_CAPACITY, DEFAULT_INITIAL_SET_CAPACITY);
}
/**
* Creates an empty HashSetValuedHashMap with the default initial
* map capacity (16) and the specified initial set capacity.
*
* @param initialSetCapacity the initial capacity used for value collections
*/
public HashSetValuedHashMap(int initialSetCapacity) {
this(DEFAULT_INITIAL_MAP_CAPACITY, initialSetCapacity);
}
/**
* Creates an empty HashSetValuedHashMap with the specified initial
* map and list capacities.
*
* @param initialMapCapacity the initial hashmap capacity
* @param initialSetCapacity the initial capacity used for value collections
*/
public HashSetValuedHashMap(int initialMapCapacity, int initialSetCapacity) {
super(new HashMap>(initialMapCapacity));
this.initialSetCapacity = initialSetCapacity;
}
/**
* Creates an HashSetValuedHashMap copying all the mappings of the given map.
*
* @param map a MultiValuedMap to copy into this map
*/
public HashSetValuedHashMap(final MultiValuedMap map) {
this(map.size(), DEFAULT_INITIAL_SET_CAPACITY);
super.putAll(map);
}
/**
* Creates an HashSetValuedHashMap copying all the mappings of the given map.
*
* @param map a Map to copy into this map
*/
public HashSetValuedHashMap(final Map map) {
this(map.size(), DEFAULT_INITIAL_SET_CAPACITY);
super.putAll(map);
}
// -----------------------------------------------------------------------
@Override
protected HashSet createCollection() {
return new HashSet(initialSetCapacity);
}
// -----------------------------------------------------------------------
private void writeObject(ObjectOutputStream oos) throws IOException {
oos.defaultWriteObject();
doWriteObject(oos);
}
private void readObject(ObjectInputStream ois) throws IOException, ClassNotFoundException {
ois.defaultReadObject();
setMap(new HashMap>());
doReadObject(ois);
}
}