com.groupbyinc.common.apache.commons.collections4.multimap.AbstractSetValuedMap 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.multimap;
import java.util.Collections;
import java.util.Map;
import java.util.Set;
import org.apache.commons.collections4.SetUtils;
import org.apache.commons.collections4.SetValuedMap;
/**
* Abstract implementation of the {@link SetValuedMap} interface to simplify the
* creation of subclass implementations.
*
* Subclasses specify a Map implementation to use as the internal storage and
* the Set implementation to use as values.
*
* @since 4.1
* @version $Id: AbstractSetValuedMap.java 1715695 2015-11-22 21:11:49Z tn $
*/
public abstract class AbstractSetValuedMap extends AbstractMultiValuedMap
implements SetValuedMap {
/**
* Constructor needed for subclass serialisation.
*/
protected AbstractSetValuedMap() {
super();
}
/**
* A constructor that wraps, not copies
*
* @param map the map to wrap, must not be null
* @throws NullPointerException if the map is null
*/
protected AbstractSetValuedMap(Map> map) {
super(map);
}
// -----------------------------------------------------------------------
@Override
@SuppressWarnings("unchecked")
protected Map> getMap() {
return (Map>) super.getMap();
}
/**
* Creates a new value collection using the provided factory.
* @return a new list
*/
@Override
protected abstract Set createCollection();
// -----------------------------------------------------------------------
/**
* Gets the set of values associated with the specified key. This would
* return an empty set in case the mapping is not present
*
* @param key the key to retrieve
* @return the Set of values, will return an empty
* Set for no mapping
*/
@Override
public Set get(final K key) {
return wrappedCollection(key);
}
@Override
Set wrappedCollection(final K key) {
return new WrappedSet(key);
}
/**
* Removes all values associated with the specified key.
*
* A subsequent get(Object) would return an empty set.
*
* @param key the key to remove values from
* @return the Set of values removed, will return an empty,
* unmodifiable set for no mapping found.
*/
@Override
public Set remove(Object key) {
return SetUtils.emptyIfNull(getMap().remove(key));
}
// -----------------------------------------------------------------------
/**
* Wrapped set to handle add and remove on the collection returned by
* {@code get(Object)}.
*/
private class WrappedSet extends WrappedCollection implements Set {
public WrappedSet(final K key) {
super(key);
}
@Override
public boolean equals(Object other) {
final Set set = (Set) getMapping();
if (set == null) {
return Collections.emptySet().equals(other);
}
if (!(other instanceof Set)) {
return false;
}
Set otherSet = (Set) other;
return SetUtils.isEqualSet(set, otherSet);
}
@Override
public int hashCode() {
final Set set = (Set) getMapping();
return SetUtils.hashCodeForSet(set);
}
}
}