Package com.google.common.collect

Class ForwardingMap<K,V>

java.lang.Object

com.google.common.collect.ForwardingObject

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

All Implemented Interfaces:

Map<K,V>

Direct Known Subclasses:

EnumBiMap, EnumHashBiMap, ForwardingConcurrentMap, ForwardingSortedMap, ImmutableClassToInstanceMap, ImmutableTypeToInstanceMap, MutableClassToInstanceMap, MutableTypeToInstanceMap

@GwtCompatible
public abstract class ForwardingMap<K,V>
extends ForwardingObject
implements Map<K,V>

A map which forwards all its method calls to another map. Subclasses should override one or more methods to modify the behavior of the backing map as desired per the decorator pattern.

Warning: The methods of ForwardingMap forward indiscriminately to the methods of the delegate. For example, overriding put(K, V) alone will not change the behavior of putAll(java.util.Map<? extends K, ? extends V>), which can lead to unexpected behavior. In this case, you should override putAll as well, either providing your own implementation, or delegating to the provided standardPutAll method.

Each of the standard methods, where appropriate, use Objects.equal(java.lang.Object, java.lang.Object) to test equality for both keys and values. This may not be the desired behavior for map implementations that use non-standard notions of key equality, such as a SortedMap whose comparator is not consistent with equals.

The standard methods and the collection views they return are not guaranteed to be thread-safe, even when all of the methods that they depend on are thread-safe.

Since:

2.0 (imported from Google Collections Library)

Nested Class Summary

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

Map.Entry<K extends Object,V extends Object>

Method Summary

Modifier and Type	Method	Description
void	clear()
boolean	containsKey(Object key)
boolean	containsValue(Object value)
Set<Map.Entry<K,V>>	entrySet()
boolean	equals(Object object)
V	get(Object key)
int	hashCode()
boolean	isEmpty()
Set<K>	keySet()
V	put(K key, V value)
void	putAll(Map<? extends K,? extends V> map)
V	remove(Object object)
int	size()
Collection<V>	values()

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

toString

Methods inherited from class java.lang.Object

getClass, notify, notifyAll, wait, wait, wait

Methods inherited from interface java.util.Map

compute, computeIfAbsent, computeIfPresent, forEach, getOrDefault, merge, putIfAbsent, remove, replace, replace, replaceAll

Method Detail

size

public int size()

Specified by:

size in interface Map<K,V>

isEmpty

public boolean isEmpty()

Specified by:

isEmpty in interface Map<K,V>

remove

public V remove(Object object)

Specified by:

remove in interface Map<K,V>

clear

public void clear()

Specified by:

clear in interface Map<K,V>

containsKey

public boolean containsKey(@Nullable
                           Object key)

Specified by:

containsKey in interface Map<K,V>

containsValue

public boolean containsValue(@Nullable
                             Object value)

Specified by:

containsValue in interface Map<K,V>

get

public V get(@Nullable
             Object key)

Specified by:

get in interface Map<K,V>

put

public V put(K key,
             V value)

Specified by:

put in interface Map<K,V>

putAll

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

Specified by:

putAll in interface Map<K,V>

keySet

public Set<K> keySet()

Specified by:

keySet in interface Map<K,V>

values

public Collection<V> values()

Specified by:

values in interface Map<K,V>

entrySet

public Set<Map.Entry<K,V>> entrySet()

Specified by:

entrySet in interface Map<K,V>

equals

public boolean equals(@Nullable
                      Object object)

Specified by:

equals in interface Map<K,V>

Overrides:

equals in class Object

hashCode

public int hashCode()

Specified by:

hashCode in interface Map<K,V>

Overrides:

hashCode in class Object