Class HashMultimap<K,V>
- All Implemented Interfaces:
Multimap<K,,V> SetMultimap<K,,V> Serializable
Multimap using hash tables.
The multimap does not store duplicate key-value pairs. Adding a new key-value pair equal to an existing key-value pair has no effect.
Keys and values may be null. All optional multimap methods are supported, and all returned views are modifiable.
This class is not threadsafe when any concurrent operations update the multimap. Concurrent
read operations will work correctly if the last write happens-before any reads. To allow
concurrent update operations, wrap your multimap with a call to Multimaps.synchronizedSetMultimap(com.google.common.collect.SetMultimap<K, V>).
Warning: Do not modify either a key or a value of a HashMultimap in a
way that affects its Object.equals(java.lang.Object) behavior. Undefined behavior and bugs will result.
- Since:
- 2.0
- See Also:
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Nested Class Summary
Nested classes/interfaces inherited from class com.google.common.collect.AbstractMapBasedMultimap
AbstractMapBasedMultimap.WrappedCollection, AbstractMapBasedMultimap.WrappedList, AbstractMapBasedMultimap.WrappedNavigableSet, AbstractMapBasedMultimap.WrappedSet, AbstractMapBasedMultimap.WrappedSortedSetNested classes/interfaces inherited from class com.google.common.collect.AbstractMultimap
AbstractMultimap.Entries, AbstractMultimap.EntrySet, AbstractMultimap.Values -
Field Summary
FieldsModifier and TypeFieldDescriptionprivate static final int(package private) intprivate static final long -
Constructor Summary
ConstructorsModifierConstructorDescriptionprivateprivateHashMultimap(int expectedKeys, int expectedValuesPerKey) privateHashMultimap(Multimap<? extends K, ? extends V> multimap) -
Method Summary
Modifier and TypeMethodDescriptionstatic <K,V> HashMultimap <K, V> create()Creates a new, emptyHashMultimapwith the default initial capacities.static <K,V> HashMultimap <K, V> create(int expectedKeys, int expectedValuesPerKey) Constructs an emptyHashMultimapwith enough capacity to hold the specified numbers of keys and values without rehashing.static <K,V> HashMultimap <K, V> Constructs aHashMultimapwith the same mappings as the specified multimap.Creates the collection of values for a single key.private voidreadObject(ObjectInputStream stream) private voidwriteObject(ObjectOutputStream stream) Methods inherited from class com.google.common.collect.AbstractSetMultimap
asMap, createUnmodifiableEmptyCollection, entries, equals, get, put, removeAll, replaceValues, unmodifiableCollectionSubclass, wrapCollectionMethods inherited from class com.google.common.collect.AbstractMapBasedMultimap
backingMap, clear, containsKey, createAsMap, createCollection, createEntries, createKeys, createKeySet, createMaybeNavigableAsMap, createMaybeNavigableKeySet, createValues, entryIterator, entrySpliterator, forEach, setMap, size, valueIterator, values, valueSpliterator, wrapListMethods inherited from class com.google.common.collect.AbstractMultimap
containsEntry, containsValue, hashCode, isEmpty, keys, keySet, putAll, putAll, remove, toStringMethods inherited from class java.lang.Object
clone, finalize, getClass, notify, notifyAll, wait, wait, waitMethods inherited from interface com.google.common.collect.Multimap
clear, containsEntry, containsKey, containsValue, forEach, hashCode, isEmpty, keys, keySet, putAll, putAll, remove, size, values
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Field Details
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DEFAULT_VALUES_PER_KEY
private static final int DEFAULT_VALUES_PER_KEY- See Also:
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expectedValuesPerKey
transient int expectedValuesPerKey -
serialVersionUID
private static final long serialVersionUID- See Also:
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Constructor Details
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HashMultimap
private HashMultimap() -
HashMultimap
private HashMultimap(int expectedKeys, int expectedValuesPerKey) -
HashMultimap
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Method Details
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create
Creates a new, emptyHashMultimapwith the default initial capacities.You may also consider the equivalent
MultimapBuilder.hashKeys().hashSetValues().build(), which provides more control over the underlying data structure. -
create
Constructs an emptyHashMultimapwith enough capacity to hold the specified numbers of keys and values without rehashing.You may also consider the equivalent
MultimapBuilder.hashKeys(expectedKeys).hashSetValues(expectedValuesPerKey).build(), which provides more control over the underlying data structure.- Parameters:
expectedKeys- the expected number of distinct keysexpectedValuesPerKey- the expected average number of values per key- Throws:
IllegalArgumentException- ifexpectedKeysorexpectedValuesPerKeyis negative
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create
Constructs aHashMultimapwith the same mappings as the specified multimap. If a key-value mapping appears multiple times in the input multimap, it only appears once in the constructed multimap.You may also consider the equivalent
MultimapBuilder.hashKeys().hashSetValues().build(multimap), which provides more control over the underlying data structure.- Parameters:
multimap- the multimap whose contents are copied to this multimap
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createCollection
Creates the collection of values for a single key.Collections with weak, soft, or phantom references are not supported. Each call to
createCollectionshould create a new instance.The returned collection class determines whether duplicate key-value pairs are allowed.
Creates an empty
HashSetfor a collection of values for one key.- Specified by:
createCollectionin classAbstractSetMultimap<K,V> - Returns:
- a new
HashSetcontaining a collection of values for one key
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writeObject
- Throws:
IOException
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readObject
- Throws:
IOExceptionClassNotFoundException
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