Class HashBiMap<K extends @Nullable Object,V extends @Nullable Object>
- java.lang.Object
-
- java.util.AbstractMap<K,V>
-
- com.google.common.collect.HashBiMap<K,V>
-
- All Implemented Interfaces:
BiMap<K,V>
,Serializable
,Map<K,V>
@GwtCompatible public final class HashBiMap<K extends @Nullable Object,V extends @Nullable Object> extends AbstractMap<K,V> implements BiMap<K,V>, Serializable
ABiMap
backed by two hash tables. This implementation allows null keys and values. AHashBiMap
and its inverse are both serializable.This implementation guarantees insertion-based iteration order of its keys.
See the Guava User Guide article on
BiMap
.- Since:
- 2.0
- Author:
- Louis Wasserman, Mike Bostock
- See Also:
- Serialized Form
-
-
Nested Class Summary
-
Nested classes/interfaces inherited from class java.util.AbstractMap
AbstractMap.SimpleEntry<K,V>, AbstractMap.SimpleImmutableEntry<K,V>
-
-
Method Summary
All Methods Static Methods Instance Methods Concrete Methods Modifier and Type Method Description void
clear()
Removes all of the mappings from this map (optional operation).boolean
containsKey(Object key)
Returnstrue
if this map contains a mapping for the specified key.boolean
containsValue(Object value)
Returnstrue
if this BiMap contains an entry whose value is equal tovalue
(or, equivalently, if this inverse view contains a key that is equal tovalue
).static <K extends @Nullable Object,V extends @Nullable Object>
HashBiMap<K,V>create()
Returns a new, emptyHashBiMap
with the default initial capacity (16).static <K extends @Nullable Object,V extends @Nullable Object>
HashBiMap<K,V>create(int expectedSize)
Constructs a new, empty bimap with the specified expected size.static <K extends @Nullable Object,V extends @Nullable Object>
HashBiMap<K,V>create(Map<? extends K,? extends V> map)
Constructs a new bimap containing initial values frommap
.Set<Map.Entry<K,V>>
entrySet()
Returns aSet
view of the mappings contained in this map.V
forcePut(K key, V value)
An alternate form ofput
that silently removes any existing entry with the valuevalue
before proceeding with theBiMap.put(K, V)
operation.V
get(Object key)
Returns the value to which the specified key is mapped, ornull
if this map contains no mapping for the key.BiMap<V,K>
inverse()
Returns the inverse view of this bimap, which maps each of this bimap's values to its associated key.Set<K>
keySet()
Returns aSet
view of the keys contained in this map.V
put(K key, V value)
Associates the specified value with the specified key in this map (optional operation).V
remove(Object key)
Removes the mapping for a key from this map if it is present (optional operation).int
size()
Returns the number of key-value mappings in this map.Set<V>
values()
Returns aCollection
view of the values contained in this map.-
Methods inherited from class java.util.AbstractMap
clone, equals, hashCode, isEmpty, putAll, toString
-
Methods inherited from class java.lang.Object
finalize, getClass, notify, notifyAll, wait, wait, wait
-
Methods inherited from interface java.util.Map
compute, computeIfAbsent, computeIfPresent, equals, forEach, getOrDefault, hashCode, isEmpty, merge, putIfAbsent, remove, replace, replace, replaceAll
-
-
-
-
Method Detail
-
create
public static <K extends @Nullable Object,V extends @Nullable Object> HashBiMap<K,V> create()
Returns a new, emptyHashBiMap
with the default initial capacity (16).
-
create
public static <K extends @Nullable Object,V extends @Nullable Object> HashBiMap<K,V> create(int expectedSize)
Constructs a new, empty bimap with the specified expected size.- Parameters:
expectedSize
- the expected number of entries- Throws:
IllegalArgumentException
- if the specified expected size is negative
-
create
public static <K extends @Nullable Object,V extends @Nullable Object> HashBiMap<K,V> create(Map<? extends K,? extends V> map)
Constructs a new bimap containing initial values frommap
. The bimap is created with an initial capacity sufficient to hold the mappings in the specified map.
-
size
public int size()
Description copied from class:java.util.AbstractMap
Returns the number of key-value mappings in this map. If the map contains more thanInteger.MAX_VALUE
elements, returnsInteger.MAX_VALUE
.
-
containsKey
public boolean containsKey(@CheckForNull Object key)
Description copied from class:java.util.AbstractMap
Returnstrue
if this map contains a mapping for the specified key. More formally, returnstrue
if and only if this map contains a mapping for a keyk
such thatObjects.equals(key, k)
. (There can be at most one such mapping.)- Specified by:
containsKey
in interfaceMap<K extends @Nullable Object,V extends @Nullable Object>
- Overrides:
containsKey
in classAbstractMap<K extends @Nullable Object,V extends @Nullable Object>
- Parameters:
key
- key whose presence in this map is to be tested- Returns:
true
if this map contains a mapping for the specified key
-
containsValue
public boolean containsValue(@CheckForNull Object value)
Returnstrue
if this BiMap contains an entry whose value is equal tovalue
(or, equivalently, if this inverse view contains a key that is equal tovalue
).Due to the property that values in a BiMap are unique, this will tend to execute in faster-than-linear time.
- Specified by:
containsValue
in interfaceMap<K extends @Nullable Object,V extends @Nullable Object>
- Overrides:
containsValue
in classAbstractMap<K extends @Nullable Object,V extends @Nullable Object>
- Parameters:
value
- the object to search for in the values of this BiMap- Returns:
- true if a mapping exists from a key to the specified value
-
get
@CheckForNull public V get(@CheckForNull Object key)
Description copied from class:java.util.AbstractMap
Returns the value to which the specified key is mapped, ornull
if this map contains no mapping for the key.More formally, if this map contains a mapping from a key
k
to a valuev
such thatObjects.equals(key, k)
, then this method returnsv
; otherwise it returnsnull
. (There can be at most one such mapping.)If this map permits null values, then a return value of
null
does not necessarily indicate that the map contains no mapping for the key; it's also possible that the map explicitly maps the key tonull
. ThecontainsKey
operation may be used to distinguish these two cases.- Specified by:
get
in interfaceMap<K extends @Nullable Object,V extends @Nullable Object>
- Overrides:
get
in classAbstractMap<K extends @Nullable Object,V extends @Nullable Object>
- Parameters:
key
- the key whose associated value is to be returned- Returns:
- the value to which the specified key is mapped, or
null
if this map contains no mapping for the key
-
put
@CanIgnoreReturnValue @CheckForNull public V put(K key, V value)
Description copied from class:java.util.AbstractMap
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 mapm
is said to contain a mapping for a keyk
if and only ifm.containsKey(k)
would returntrue
.)- Specified by:
put
in interfaceBiMap<K extends @Nullable Object,V extends @Nullable Object>
- Specified by:
put
in interfaceMap<K extends @Nullable Object,V extends @Nullable Object>
- Overrides:
put
in classAbstractMap<K extends @Nullable Object,V extends @Nullable Object>
- Parameters:
key
- key with which the specified value is to be associatedvalue
- value to be associated with the specified key- Returns:
- the previous value associated with
key
, ornull
if there was no mapping forkey
. (Anull
return can also indicate that the map previously associatednull
withkey
, if the implementation supportsnull
values.)
-
forcePut
@CanIgnoreReturnValue @CheckForNull public V forcePut(K key, V value)
Description copied from interface:BiMap
An alternate form ofput
that silently removes any existing entry with the valuevalue
before proceeding with theBiMap.put(K, V)
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.
- Specified by:
forcePut
in interfaceBiMap<K extends @Nullable Object,V extends @Nullable Object>
- Parameters:
key
- the key with which the specified value is to be associatedvalue
- the value to be associated with the specified key- Returns:
- the value that was previously associated with the key, or
null
if there was no previous entry. (If the bimap contains null values, thenforcePut
, likeput
, returnsnull
both if the key is absent and if it is present with a null value.)
-
remove
@CanIgnoreReturnValue @CheckForNull public V remove(@CheckForNull Object key)
Description copied from class:java.util.AbstractMap
Removes the mapping for a key from this map if it is present (optional operation). More formally, if this map contains a mapping from keyk
to valuev
such thatObjects.equals(key, k)
, that mapping is removed. (The map can contain at most one such mapping.)Returns the value to which this map previously associated the key, or
null
if the map contained no mapping for the key.If this map permits null values, then a return value of
null
does not necessarily indicate that the map contained no mapping for the key; it's also possible that the map explicitly mapped the key tonull
.The map will not contain a mapping for the specified key once the call returns.
- Specified by:
remove
in interfaceMap<K extends @Nullable Object,V extends @Nullable Object>
- Overrides:
remove
in classAbstractMap<K extends @Nullable Object,V extends @Nullable Object>
- Parameters:
key
- key whose mapping is to be removed from the map- Returns:
- the previous value associated with
key
, ornull
if there was no mapping forkey
.
-
clear
public void clear()
Description copied from class:java.util.AbstractMap
Removes all of the mappings from this map (optional operation). The map will be empty after this call returns.
-
keySet
public Set<K> keySet()
Description copied from class:java.util.AbstractMap
Returns aSet
view of the keys contained in this map. The set is backed by the map, so changes to the map are reflected in the set, and vice-versa. If the map is modified while an iteration over the set is in progress (except through the iterator's ownremove
operation), the results of the iteration are undefined. The set supports element removal, which removes the corresponding mapping from the map, via theIterator.remove
,Set.remove
,removeAll
,retainAll
, andclear
operations. It does not support theadd
oraddAll
operations.
-
values
public Set<V> values()
Description copied from class:java.util.AbstractMap
Returns aCollection
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 ownremove
operation), the results of the iteration are undefined. The collection supports element removal, which removes the corresponding mapping from the map, via theIterator.remove
,Collection.remove
,removeAll
,retainAll
andclear
operations. It does not support theadd
oraddAll
operations.- Specified by:
values
in interfaceBiMap<K extends @Nullable Object,V extends @Nullable Object>
- Specified by:
values
in interfaceMap<K extends @Nullable Object,V extends @Nullable Object>
- Overrides:
values
in classAbstractMap<K extends @Nullable Object,V extends @Nullable Object>
- Returns:
- a collection view of the values contained in this map
-
entrySet
public Set<Map.Entry<K,V>> entrySet()
Description copied from interface:java.util.Map
Returns aSet
view of the mappings contained in this map. The set is backed by the map, so changes to the map are reflected in the set, and vice-versa. If the map is modified while an iteration over the set is in progress (except through the iterator's ownremove
operation, or through thesetValue
operation on a map entry returned by the iterator) the results of the iteration are undefined. The set supports element removal, which removes the corresponding mapping from the map, via theIterator.remove
,Set.remove
,removeAll
,retainAll
andclear
operations. It does not support theadd
oraddAll
operations.
-
inverse
public BiMap<V,K> inverse()
Description copied from interface:BiMap
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.
-
-