com.google.common.collect

Class EnumHashBiMap<K extends Enum<K>,V>

java.lang.Object

com.google.common.collect.ForwardingObject

com.google.common.collect.ForwardingMap<K,V>

com.google.common.collect.EnumHashBiMap<K,V>

All Implemented Interfaces:

BiMap<K,V>, Serializable, Map<K,V>

@GwtCompatible(emulated=true)
public final class EnumHashBiMap<K extends Enum<K>,V>
extends ForwardingMap<K,V>

A BiMap backed by an EnumMap instance for keys-to-values, and a HashMap instance for values-to-keys. Null keys are not permitted, but null values are. An EnumHashBiMap and its inverse are both serializable.

See the Guava User Guide article on BiMap.

Since:

2.0

Author:

Mike Bostock

See Also:

Serialized Form

Nested Class Summary

Nested classes/interfaces inherited from class com.google.common.collect.ForwardingMap

ForwardingMap.StandardEntrySet, ForwardingMap.StandardKeySet, ForwardingMap.StandardValues

Nested classes/interfaces inherited from interface java.util.Map

Map.Entry<K,V>

Method Summary

Modifier and Type	Method and Description
void	clear() Removes all of the mappings from this map (optional operation).
boolean	containsValue(@Nullable Object value) Returns true if this map maps one or more keys to the specified value.
static <K extends Enum<K>,V> EnumHashBiMap<K,V>	create(Class<K> keyType) Returns a new, empty EnumHashBiMap using the specified key type.
static <K extends Enum<K>,V> EnumHashBiMap<K,V>	create(Map<K,? extends V> map) Constructs a new bimap with the same mappings as the specified map.
protected Map<K,V>	delegate() Returns the backing delegate instance that methods are forwarded to.
Set<Map.Entry<K,V>>	entrySet() Returns a Set view of the mappings contained in this map.
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 BiMap.put(K, V) operation.
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 a Set view of the keys contained in this map.
Class<K>	keyType() Returns the associated key type.
V	put(K key, V value) Associates the specified value with the specified key in this map (optional operation).
void	putAll(Map<? extends K,? extends V> map) Copies all of the mappings from the specified map to this map (optional operation).
V	remove(@Nullable Object key) Removes the mapping for a key from this map if it is present (optional operation).
void	replaceAll(BiFunction<? super K,? super V,? extends V> function) Replaces each entry's value with the result of invoking the given function on that entry until all entries have been processed or the function throws an exception.
Set<V>	values() Returns a Collection view of the values contained in this map.

Methods inherited from class com.google.common.collect.ForwardingMap

containsKey, equals, get, hashCode, isEmpty, size, standardClear, standardContainsKey, standardContainsValue, standardEquals, standardHashCode, standardIsEmpty, standardPutAll, standardRemove, standardToString

Methods inherited from class com.google.common.collect.ForwardingObject

toString

Methods inherited from class java.lang.Object

clone, finalize, getClass, notify, notifyAll, wait, wait, wait

Methods inherited from interface java.util.Map

compute, computeIfAbsent, computeIfPresent, containsKey, equals, forEach, get, getOrDefault, hashCode, isEmpty, merge, putIfAbsent, remove, replace, replace, size

Method Detail

create

public static <K extends Enum<K>,V> EnumHashBiMap<K,V> create(Class<K> keyType)

Returns a new, empty EnumHashBiMap using the specified key type.

Parameters:

keyType - the key type

create

public static <K extends Enum<K>,V> EnumHashBiMap<K,V> create(Map<K,? extends V> map)

Constructs a new bimap with the same mappings as the specified map. If the specified map is an EnumHashBiMap or an EnumBiMap, the new bimap has the same key type as the input bimap. Otherwise, the specified map must contain at least one mapping, in order to determine the key type.

Parameters:

map - the map whose mappings are to be placed in this map

Throws:

IllegalArgumentException - if map is not an EnumBiMap or an EnumHashBiMap instance and contains no mappings

put

@CanIgnoreReturnValue
public V put(K key,
                                   V value)

Description copied from interface: java.util.Map

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.)

Specified by:

put in interface BiMap<K extends Enum<K>,V>

Specified by:

put in interface Map<K extends Enum<K>,V>

Parameters:

key - key with which the specified value is to be associated

value - value to be associated with the specified key

Returns:

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.)

forcePut

@CanIgnoreReturnValue
public V forcePut(K key,
                                        V value)

Description copied from interface: BiMap

An alternate form of put that silently removes any existing entry with the value value before proceeding with the BiMap.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 interface BiMap<K extends Enum<K>,V>

Parameters:

key - the key with which the specified value is to be associated

value - the value to be associated with the specified key

Returns:

the value which was previously associated with the key, which may be null, or null if there was no previous entry

keyType

public Class<K> keyType()

Returns the associated key type.

delegate

protected Map<K,V> delegate()

Description copied from class: ForwardingObject

Returns the backing delegate instance that methods are forwarded to. Abstract subclasses generally override this method with an abstract method that has a more specific return type, such as ForwardingSet.delegate(). Concrete subclasses override this method to supply the instance being decorated.

Specified by:

delegate in class ForwardingMap<K,V>

containsValue

public boolean containsValue(@Nullable Object value)

Description copied from interface: java.util.Map

Returns true if this map maps one or more keys to the specified value. More formally, returns true if and only if this map contains at least one mapping to a value v such that (value==null ? v==null : value.equals(v)). This operation will probably require time linear in the map size for most implementations of the Map interface.

Specified by:

containsValue in interface Map<K,V>

Overrides:

containsValue in class ForwardingMap<K,V>

Parameters:

value - value whose presence in this map is to be tested

Returns:

true if this map maps one or more keys to the specified value

remove

@CanIgnoreReturnValue
public V remove(@Nullable Object key)

Description copied from interface: java.util.Map

Removes the mapping for a key from this map if it is present (optional operation). More formally, if this map contains a mapping from key k to value v such that (key==null ? k==null : key.equals(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 to null.

The map will not contain a mapping for the specified key once the call returns.

Specified by:

remove in interface Map<K,V>

Overrides:

remove in class ForwardingMap<K,V>

Parameters:

key - key whose mapping is to be removed from the map

Returns:

the previous value associated with key, or null if there was no mapping for key.

putAll

public void putAll(Map<? extends K,? extends V> map)

Description copied from interface: java.util.Map

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.

Specified by:

putAll in interface BiMap<K,V>

Specified by:

putAll in interface Map<K,V>

Overrides:

putAll in class ForwardingMap<K,V>

Parameters:

map - mappings to be stored in this map

replaceAll

public void replaceAll(BiFunction<? super K,? super V,? extends V> function)

Description copied from interface: java.util.Map

Replaces each entry's value with the result of invoking the given function on that entry until all entries have been processed or the function throws an exception. Exceptions thrown by the function are relayed to the caller.

Specified by:

replaceAll in interface Map<K,V>

Parameters:

function - the function to apply to each entry

clear

public void clear()

Description copied from interface: java.util.Map

Removes all of the mappings from this map (optional operation). The map will be empty after this call returns.

Specified by:

clear in interface Map<K,V>

Overrides:

clear in class ForwardingMap<K,V>

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.

Specified by:

inverse in interface BiMap<K,V>

Returns:

the inverse view of this bimap

keySet

public Set<K> keySet()

Description copied from interface: java.util.Map

Returns a Set 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 own remove operation), the results of the iteration are undefined. The set supports element removal, which removes the corresponding mapping from the map, via the Iterator.remove, Set.remove, removeAll, retainAll, and clear operations. It does not support the add or addAll operations.

Specified by:

keySet in interface Map<K,V>

Overrides:

keySet in class ForwardingMap<K,V>

Returns:

a set view of the keys contained in this map

values

public Set<V> values()

Description copied from interface: java.util.Map

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.

Specified by:

values in interface BiMap<K,V>

Specified by:

values in interface Map<K,V>

Overrides:

values in class ForwardingMap<K,V>

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 a Set 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 own remove operation, or through the setValue 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 the Iterator.remove, Set.remove, removeAll, retainAll and clear operations. It does not support the add or addAll operations.

Specified by:

entrySet in interface Map<K,V>

Overrides:

entrySet in class ForwardingMap<K,V>

Returns:

a set view of the mappings contained in this map