Class AbstractDualBidiMap<K,V>
- Type Parameters:
K- the type of the keys in the mapV- the type of the values in the map
- All Implemented Interfaces:
Map<K,,V> BidiMap<K,,V> Get<K,,V> IterableGet<K,,V> IterableMap<K,,V> Put<K,V>
- Direct Known Subclasses:
DualHashBidiMap,DualLinkedHashBidiMap,DualTreeBidiMap
BidiMap implemented using two maps.
An implementation can be written simply by implementing the
createBidiMap(Map, Map, BidiMap) method.
- Since:
- 3.0
- See Also:
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Nested Class Summary
Nested ClassesModifier and TypeClassDescriptionprotected static classInner class MapIterator.protected static classInner class EntrySet.protected static classInner class EntrySetIterator.protected static classInner class KeySet.protected static classInner class KeySetIterator.protected static classInner class MapEntry.protected static classInner class Values.protected static classInner class ValuesIterator.protected static classInner class View. -
Constructor Summary
ConstructorsModifierConstructorDescriptionprotectedCreates an empty map, initialized bycreateMap.protectedCreates an empty map using the two maps specified as storage.protectedConstructs a map that decorates the specified maps, used by the subclasscreateBidiMapimplementation. -
Method Summary
Modifier and TypeMethodDescriptionvoidclear()Removes all of the mappings from this map.booleancontainsKey(Object key) Tests for presence of a given key.booleancontainsValue(Object value) Tests for presence of a given value.Creates a new instance of the subclass.createEntrySetIterator(Iterator<Map.Entry<K, V>> iterator) Creates an entry set iterator.createKeySetIterator(Iterator<K> iterator) Creates a key set iterator.createValuesIterator(Iterator<V> iterator) Creates a values iterator.entrySet()Gets an entrySet view of the map.booleanGets a value at a given key.Gets the key that is currently mapped to the specified value.inthashCode()Gets a view of this map where the keys and values are reversed.booleanisEmpty()Tests whether this instance contains any key-value mappings.keySet()Gets a keySet view of the map.Obtains aMapIteratorover the map.Puts the key-value pair into the map, replacing any previous pair.voidCopies all of the mappings from the specified map to this map.Remove a key-value mappings.removeValue(Object value) Removes the key-value pair that is currently mapped to the specified value (optional operation).intsize()Gets the number of key-value mappings in this map.toString()values()Gets a values view of the map.Methods inherited from class java.lang.Object
clone, finalize, getClass, notify, notifyAll, wait, wait, waitMethods inherited from interface java.util.Map
compute, computeIfAbsent, computeIfPresent, forEach, getOrDefault, merge, putIfAbsent, remove, replace, replace, replaceAll
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Constructor Details
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AbstractDualBidiMap
protected AbstractDualBidiMap()Creates an empty map, initialized bycreateMap.This constructor remains in place for deserialization. All other usage is deprecated in favor of
AbstractDualBidiMap(Map, Map). -
AbstractDualBidiMap
Creates an empty map using the two maps specified as storage.The two maps must be a matching pair, normal and reverse. They will typically both be empty.
Neither map is validated, so nulls may be passed in. If you choose to do this then the subclass constructor must populate the
maps[]instance variable itself.- Parameters:
normalMap- the normal direction mapreverseMap- the reverse direction map- Since:
- 3.1
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AbstractDualBidiMap
Constructs a map that decorates the specified maps, used by the subclasscreateBidiMapimplementation.- Parameters:
normalMap- the normal direction mapreverseMap- the reverse direction mapinverseBidiMap- the inverse BidiMap
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Method Details
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clear
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containsKey
Description copied from interface:GetTests for presence of a given key.- Specified by:
containsKeyin interfaceGet<K,V> - Specified by:
containsKeyin interfaceMap<K,V> - Parameters:
key- key whose presence in this map is to be tested- Returns:
trueif this map contains a mapping for the specified key- See Also:
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containsValue
Description copied from interface:GetTests for presence of a given value.- Specified by:
containsValuein interfaceGet<K,V> - Specified by:
containsValuein interfaceMap<K,V> - Parameters:
value- value whose presence in this map is to be tested- Returns:
trueif this map maps one or more keys to the specified value- See Also:
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createBidiMap
protected abstract BidiMap<V,K> createBidiMap(Map<V, K> normalMap, Map<K, V> reverseMap, BidiMap<K, V> inverseMap) Creates a new instance of the subclass.- Parameters:
normalMap- the normal direction mapreverseMap- the reverse direction mapinverseMap- this map, which is the inverse in the new map- Returns:
- the bidi map
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createEntrySetIterator
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createKeySetIterator
Creates a key set iterator. Subclasses can override this to return iterators with different properties.- Parameters:
iterator- the iterator to decorate- Returns:
- the keySet iterator
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createValuesIterator
Creates a values iterator. Subclasses can override this to return iterators with different properties.- Parameters:
iterator- the iterator to decorate- Returns:
- the values iterator
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entrySet
Gets an entrySet view of the map. Changes made on the set are reflected in the map. The set supports remove and clear but not add.The Map Entry setValue() method only allow a new value to be set. If the value being set is already in the map, an IllegalArgumentException is thrown (as setValue cannot change the size of the map).
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equals
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get
Description copied from interface:GetGets a value at a given key. -
getKey
Description copied from interface:BidiMapGets the key that is currently mapped to the specified value.If the value is not contained in the map,
nullis returned.Implementations should seek to make this method perform equally as well as
get(Object). -
hashCode
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inverseBidiMap
Description copied from interface:BidiMapGets a view of this map where the keys and values are reversed.Changes to one map will be visible in the other and vice versa. This enables both directions of the map to be accessed as a
Map.Implementations should seek to avoid creating a new object every time this method is called. See
AbstractMap.values()etc. Calling this method on the inverse map should return the original.- Specified by:
inverseBidiMapin interfaceBidiMap<K,V> - Returns:
- an inverted bidirectional map
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isEmpty
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keySet
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mapIterator
Obtains aMapIteratorover the map. The iterator implementsAbstractDualBidiMap.BidiMapIterator. This implementation relies on the entrySet iterator.- Specified by:
mapIteratorin interfaceIterableGet<K,V> - Returns:
- a map iterator
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put
Description copied from interface:BidiMapPuts the key-value pair into the map, replacing any previous pair.When adding a key-value pair, the value may already exist in the map against a different key. That mapping is removed, to ensure that the value only occurs once in the inverse map.
BidiMap map1 = new DualHashBidiMap(); map.put("A","B"); // contains A mapped to B, as per Map map.put("A","C"); // contains A mapped to C, as per Map BidiMap map2 = new DualHashBidiMap(); map.put("A","B"); // contains A mapped to B, as per Map map.put("C","B"); // contains C mapped to B, key A is removed -
putAll
Description copied from interface:PutCopies all of the mappings from the specified map to this map. -
remove
Description copied from interface:GetRemove a key-value mappings. -
removeValue
Description copied from interface:BidiMapRemoves the key-value pair that is currently mapped to the specified value (optional operation).If the value is not contained in the map,
nullis returned.Implementations should seek to make this method perform equally as well as
remove(Object).- Specified by:
removeValuein interfaceBidiMap<K,V> - Parameters:
value- the value to find the key-value pair for- Returns:
- the key that was removed,
nullif nothing removed
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size
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toString
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values
Gets a values view of the map. Changes made on the view are reflected in the map. The set supports remove and clear but not add.
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