@GwtCompatible public abstract class ForwardingMultimap<K,V> extends ForwardingObject implements Multimap<K,V>
default method warning: This class does not forward calls to default methods. Instead, it inherits their default implementations. When those implementations
invoke methods, they invoke methods on the ForwardingMultimap.
| Modifier | Constructor and Description |
|---|---|
protected |
ForwardingMultimap()
Constructor for use by subclasses.
|
| Modifier and Type | Method and Description |
|---|---|
Map<K,Collection<V>> |
asMap()
Returns a view of this multimap as a
Map from each distinct key to the nonempty
collection of that key's associated values. |
void |
clear()
Removes all key-value pairs from the multimap, leaving it empty.
|
boolean |
containsEntry(@Nullable Object key,
@Nullable Object value)
Returns
true if this multimap contains at least one key-value pair with the key key and the value value. |
boolean |
containsKey(@Nullable Object key)
Returns
true if this multimap contains at least one key-value pair with the key key. |
boolean |
containsValue(@Nullable Object value)
Returns
true if this multimap contains at least one key-value pair with the value
value. |
protected abstract Multimap<K,V> |
delegate()
Returns the backing delegate instance that methods are forwarded to.
|
Collection<Map.Entry<K,V>> |
entries()
Returns a view collection of all key-value pairs contained in this multimap, as
Map.Entry
instances. |
boolean |
equals(@Nullable Object object)
Indicates whether some other object is "equal to" this one.
|
Collection<V> |
get(K key)
Returns a view collection of the values associated with
key in this multimap, if any. |
int |
hashCode()
Returns a hash code value for the object.
|
boolean |
isEmpty()
Returns
true if this multimap contains no key-value pairs. |
Multiset<K> |
keys()
Returns a view collection containing the key from each key-value pair in this multimap,
without collapsing duplicates.
|
Set<K> |
keySet()
Returns a view collection of all distinct keys contained in this multimap.
|
boolean |
put(K key,
V value)
Stores a key-value pair in this multimap.
|
boolean |
putAll(K key,
Iterable<? extends V> values)
Stores a key-value pair in this multimap for each of
values, all using the same key,
key. |
boolean |
putAll(Multimap<? extends K,? extends V> multimap)
Stores all key-value pairs of
multimap in this multimap, in the order returned by
multimap.entries(). |
boolean |
remove(@Nullable Object key,
@Nullable Object value)
Removes a single key-value pair with the key
key and the value value from this
multimap, if such exists. |
Collection<V> |
removeAll(@Nullable Object key)
Removes all values associated with the key
key. |
Collection<V> |
replaceValues(K key,
Iterable<? extends V> values)
Stores a collection of values with the same key, replacing any existing values for that key.
|
int |
size()
Returns the number of key-value pairs in this multimap.
|
Collection<V> |
values()
Returns a view collection containing the value from each key-value pair contained in
this multimap, without collapsing duplicates (so
values().size() == size()). |
toStringprotected ForwardingMultimap()
protected abstract Multimap<K,V> delegate()
ForwardingObjectForwardingSet.delegate(). Concrete subclasses override this method to supply the
instance being decorated.delegate in class ForwardingObjectpublic Map<K,Collection<V>> asMap()
MultimapMap from each distinct key to the nonempty
collection of that key's associated values. Note that this.asMap().get(k) is equivalent
to this.get(k) only when k is a key contained in the multimap; otherwise it
returns null as opposed to an empty collection.
Changes to the returned map or the collections that serve as its values will update the
underlying multimap, and vice versa. The map does not support put or putAll,
nor do its entries support setValue.
public void clear()
Multimappublic boolean containsEntry(@Nullable Object key, @Nullable Object value)
Multimaptrue if this multimap contains at least one key-value pair with the key key and the value value.containsEntry in interface Multimap<K,V>public boolean containsKey(@Nullable Object key)
Multimaptrue if this multimap contains at least one key-value pair with the key key.containsKey in interface Multimap<K,V>public boolean containsValue(@Nullable Object value)
Multimaptrue if this multimap contains at least one key-value pair with the value
value.containsValue in interface Multimap<K,V>public Collection<Map.Entry<K,V>> entries()
MultimapMap.Entry
instances.
Changes to the returned collection or the entries it contains will update the underlying multimap, and vice versa. However, adding to the returned collection is not possible.
public Collection<V> get(K key)
Multimapkey in this multimap, if any.
Note that when containsKey(key) is false, this returns an empty collection, not null.
Changes to the returned collection will update the underlying multimap, and vice versa.
public boolean isEmpty()
Multimaptrue if this multimap contains no key-value pairs. Equivalent to size()
== 0, but can in some cases be more efficient.public Multiset<K> keys()
Multimapkeys().count(k) == get(k).size() for all k.
Changes to the returned multiset will update the underlying multimap, and vice versa. However, adding to the returned collection is not possible.
public Set<K> keySet()
MultimapChanges to the returned set will update the underlying multimap, and vice versa. However, adding to the returned set is not possible.
@CanIgnoreReturnValue public boolean put(K key, V value)
MultimapSome multimap implementations allow duplicate key-value pairs, in which case put
always adds a new key-value pair and increases the multimap size by 1. Other implementations
prohibit duplicates, and storing a key-value pair that's already in the multimap has no effect.
@CanIgnoreReturnValue public boolean putAll(K key, Iterable<? extends V> values)
Multimapvalues, all using the same key,
key. Equivalent to (but expected to be more efficient than):
for (V value : values) {
put(key, value);
}
In particular, this is a no-op if values is empty.
@CanIgnoreReturnValue public boolean putAll(Multimap<? extends K,? extends V> multimap)
Multimapmultimap in this multimap, in the order returned by
multimap.entries().@CanIgnoreReturnValue public boolean remove(@Nullable Object key, @Nullable Object value)
Multimapkey and the value value from this
multimap, if such exists. If multiple key-value pairs in the multimap fit this description,
which one is removed is unspecified.@CanIgnoreReturnValue public Collection<V> removeAll(@Nullable Object key)
Multimapkey.
Once this method returns, key will not be mapped to any values, so it will not
appear in Multimap.keySet(), Multimap.asMap(), or any other views.
@CanIgnoreReturnValue public Collection<V> replaceValues(K key, Iterable<? extends V> values)
MultimapIf values is empty, this is equivalent to removeAll(key).
replaceValues in interface Multimap<K,V>public int size()
MultimapNote: this method does not return the number of distinct keys in the multimap,
which is given by keySet().size() or asMap().size(). See the opening section of
the Multimap class documentation for clarification.
public Collection<V> values()
Multimapvalues().size() == size()).
Changes to the returned collection will update the underlying multimap, and vice versa. However, adding to the returned collection is not possible.
public boolean equals(@Nullable Object object)
java.lang.Object
The equals method implements an equivalence relation
on non-null object references:
x, x.equals(x) should return
true.
x and y, x.equals(y)
should return true if and only if
y.equals(x) returns true.
x, y, and z, if
x.equals(y) returns true and
y.equals(z) returns true, then
x.equals(z) should return true.
x and y, multiple invocations of
x.equals(y) consistently return true
or consistently return false, provided no
information used in equals comparisons on the
objects is modified.
x,
x.equals(null) should return false.
The equals method for class Object implements
the most discriminating possible equivalence relation on objects;
that is, for any non-null reference values x and
y, this method returns true if and only
if x and y refer to the same object
(x == y has the value true).
Note that it is generally necessary to override the hashCode
method whenever this method is overridden, so as to maintain the
general contract for the hashCode method, which states
that equal objects must have equal hash codes.
public int hashCode()
java.lang.ObjectHashMap.
The general contract of hashCode is:
hashCode method
must consistently return the same integer, provided no information
used in equals comparisons on the object is modified.
This integer need not remain consistent from one execution of an
application to another execution of the same application.
equals(Object)
method, then calling the hashCode method on each of
the two objects must produce the same integer result.
Object.equals(java.lang.Object)
method, then calling the hashCode method on each of the
two objects must produce distinct integer results. However, the
programmer should be aware that producing distinct integer results
for unequal objects may improve the performance of hash tables.
As much as is reasonably practical, the hashCode method defined by
class Object does return distinct integers for distinct
objects. (This is typically implemented by converting the internal
address of the object into an integer, but this implementation
technique is not required by the
Java™ programming language.)
hashCode in interface Multimap<K,V>hashCode in class ObjectObject.equals(java.lang.Object),
System.identityHashCode(java.lang.Object)Copyright © 2010–2020. All rights reserved.