org.jboss.weld.util.collections.Multimap Maven / Gradle / Ivy
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* Copyright 2014, Red Hat, Inc., and individual contributors
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*
* Licensed 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.jboss.weld.util.collections;
import java.util.Collection;
import java.util.List;
import java.util.Map.Entry;
import java.util.Set;
/**
* A collection-like structure that maps keys to collections of values.
*
* @author Martin Kouba
* @param The key
* @param The value
*/
public interface Multimap {
/**
* Unlike com.google.common.collect.Multimap#size() this method returns the number of key-value mappings.
*
* @return the number of key-value mappings
*/
int size();
/**
*
* @return true if there are no key-value mappings
*/
boolean isEmpty();
/**
* This method never returns null. If no collection of values for a given key exists a new value collection is initialized.
*
* @param key
* @return the collection of values for the given key
*/
Collection get(K key);
/**
*
* @param key
* @param value
* @return true if the the size of the collection associated with the given key increased, false otherwise (e.g. if the collection
* of values doesn't allow duplicates)
*/
boolean put(K key, V value);
/**
*
* @param key
* @param values
* @return true if the the size of the collection associated with the given key increased, false otherwise (e.g. if the collection
* of values doesn't allow duplicates)
*/
boolean putAll(K key, Collection values);
/**
* Note that the original collection of values is completely replaced by a new collection which contains all elements from the given iterable. If the
* collection of values doesn't allow duplicates, these elements are removed.
*
* @param key
* @param values
* @return the collection of replaced values
*/
Collection replaceValues(K key, Iterable values);
/**
*
* @param key
* @return true if the multimap contains a mapping for the given key
*/
boolean containsKey(Object key);
/**
*
* @return an immutable set of keys
*/
Set keySet();
/**
* The list may include the same value multiple times if it occurs in multiple mappings or if the collection of values for the mapping allows duplicate
* elements.
*
* @return an immutable list of all the values in the multimap
*/
List values();
/**
*
* @return an immutable set of all the values in the multimap
*/
Set uniqueValues();
/**
* {@link Entry#getValue()} always returns an unmodifiable collection. {@link Entry#setValue(Object)} operation is not supported.
*
* @return an immutable set of all key-value pairs
*/
Set>> entrySet();
/**
* Removes all of the mappings.
*/
void clear();
}