Top Description Methods
com.google.common.collect

public Interface BiMap<K extends @Nullable Object, V extends @Nullable Object>

extends Map<K extends @Nullable Object, V extends @Nullable Object>
Known Direct Implementers
com.google.common.collect.HashBiMap, com.google.common.collect.HashBiMap.Inverse, com.google.common.collect.ImmutableBiMap, com.google.common.collect.Maps.UnmodifiableBiMap, com.google.common.collect.Maps.FilteredEntryBiMap, com.google.common.collect.Synchronized.SynchronizedBiMap, com.google.common.collect.AbstractBiMap
Annotations
@GwtCompatible
@ElementTypesAreNonnullByDefault
Imports
com.google.common.annotations.GwtCompatible, com.google.errorprone.annotations.CanIgnoreReturnValue, java.util.Map, .Set, javax.annotation.CheckForNull, org.checkerframework.checker.nullness.qual.Nullable

A bimap (or "bidirectional map") is a map that preserves the uniqueness of its values as well as that of its keys. This constraint enables bimaps to support an "inverse view", which is another bimap containing the same entries as this bimap but with reversed keys and values.

Implementations

See the Guava User Guide article on BiMap.

Author
Kevin Bourrillion
Since
2.0

Method Summary

Modifier and TypeMethod and Description
public V

Returns:

the value that was previously associated with the key, or null if there was no previous entry. (If the bimap contains null values, then forcePut, like put, returns null both if the key is absent and if it is present with a null value.)
forcePut
(K
the key with which the specified value is to be associated
key
,
V
the value to be associated with the specified key
value
)

An alternate form of put that silently removes any existing entry with the value value before proceeding with the put operation.

public BiMap<V, K>

Returns:

the inverse view of this bimap
inverse
()

Returns the inverse view of this bimap, which maps each of this bimap's values to its associated key.

public V
put(K
key with which the specified value is to be associated
key
,
V
value to be associated with the specified key
value
)

Redeclares java.util.Map.put.

Associates the specified value with the specified key in this map (optional operation).
public void
putAll(Map<? extends K, ? extends V>
mappings to be stored in this map
map
)

Redeclares java.util.Map.putAll.

Copies all of the mappings from the specified map to this map (optional operation).
public Set<V>
values()

Redeclares java.util.Map.values.

Returns a Collection view of the values contained in this map.
Inherited from java.util.Map:
clearcomputecomputeIfAbsentcomputeIfPresentcontainsKeycontainsValuecopyOfentryentrySetequalsforEachgetgetOrDefaulthashCodeisEmptykeySetmergeofofofofofofofofofofofofEntriesputIfAbsentremoveremovereplacereplacereplaceAllsize

Method Detail

forcePutback to summary
public V forcePut(K key, V value)

An alternate form of put that silently removes any existing entry with the value value before proceeding with the put operation. If the bimap previously contained the provided key-value mapping, this method has no effect.

Note that a successful call to this method could cause the size of the bimap to increase by one, stay the same, or even decrease by one.

Warning

If an existing entry with this value is removed, the key for that entry is discarded and not returned.

Parameters
key:K

the key with which the specified value is to be associated

value:V

the value to be associated with the specified key

Returns:V

the value that was previously associated with the key, or null if there was no previous entry. (If the bimap contains null values, then forcePut, like put, returns null both if the key is absent and if it is present with a null value.)

Annotations
@CanIgnoreReturnValue
@CheckForNull
inverseback to summary
public BiMap<V, K> inverse()

Returns the inverse view of this bimap, which maps each of this bimap's values to its associated key. The two bimaps are backed by the same data; any changes to one will appear in the other.

Note

There is no guaranteed correspondence between the iteration order of a bimap and that of its inverse.

Returns:BiMap<V, K>

the inverse view of this bimap

putback to summary
public V put(K key, V value)

Redeclares java.util.Map.put.

Doc from java.util.Map.put.

Associates the specified value with the specified key in this map (optional operation). If the map previously contained a mapping for the key, the old value is replaced by the specified value. (A map m is said to contain a mapping for a key k if and only if m.containsKey(k) would return true.)

Parameters
key:K

key with which the specified value is to be associated

value:V

value to be associated with the specified key

Returns:V

the previous value associated with key, or null if there was no mapping for key. (A null return can also indicate that the map previously associated null with key, if the implementation supports null values.)

Annotations
@CanIgnoreReturnValue
@Override
@CheckForNull
Exceptions
IllegalArgumentException:
if the given value is already bound to a different key in this bimap. The bimap will remain unmodified in this event. To avoid this exception, call forcePut instead.
putAllback to summary
public void putAll(Map<? extends K, ? extends V> map)

Redeclares java.util.Map.putAll.

Doc from java.util.Map.putAll.

Copies all of the mappings from the specified map to this map (optional operation). The effect of this call is equivalent to that of calling put(k, v) on this map once for each mapping from key k to value v in the specified map. The behavior of this operation is undefined if the specified map is modified while the operation is in progress. If the specified map has a defined encounter order, processing of its mappings generally occurs in that order.

Warning

the results of calling this method may vary depending on the iteration order of map.

Parameters
map:Map<? extends K, ? extends V>

mappings to be stored in this map

Annotations
@Override
Exceptions
IllegalArgumentException:
if an attempt to put any entry fails. Note that some map entries may have been added to the bimap before the exception was thrown.
valuesback to summary
public Set<V> values()

Redeclares java.util.Map.values.

Doc from java.util.Map.values.

Returns a Collection view of the values contained in this map. The collection is backed by the map, so changes to the map are reflected in the collection, and vice-versa. If the map is modified while an iteration over the collection is in progress (except through the iterator's own remove operation), the results of the iteration are undefined. The collection supports element removal, which removes the corresponding mapping from the map, via the Iterator.remove, Collection.remove, removeAll, retainAll and clear operations. It does not support the add or addAll operations.

Because a bimap has unique values, this method returns a Set, instead of the java.util.Collection specified in the Map interface.

Returns:Set<V>

a collection view of the values contained in this map

Annotations
@Override