@GwtCompatible public abstract class ForwardingMultimap<K,V> extends ForwardingObject implements Multimap<K,V>
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(Object key,
Object value)
Returns
true if this multimap contains at least one key-value pair
with the key key and the value value . |
boolean |
containsKey(Object key)
Returns
true if this multimap contains at least one key-value pair
with the key key . |
boolean |
containsValue(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(Object object)
Compares the specified object with this multimap for equality.
|
Collection<V> |
get(K key)
Returns a view collection of the values associated with
key in this
multimap, if any. |
int |
hashCode()
Returns the hash code for this multimap.
|
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(Object key,
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(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() ). |
toString
protected ForwardingMultimap()
protected abstract Multimap<K,V> delegate()
ForwardingObject
ForwardingSet.delegate()
. Concrete subclasses override this method to supply
the instance being decorated.delegate
in class ForwardingObject
public Map<K,Collection<V>> asMap()
Multimap
Map
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()
Multimap
public boolean containsEntry(@Nullable Object key, @Nullable Object value)
Multimap
true
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)
Multimap
true
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)
Multimap
true
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()
Multimap
Map.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(@Nullable K key)
Multimap
key
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()
Multimap
true
if this multimap contains no key-value pairs.
Equivalent to size() == 0
, but can in some cases be more efficient.public Multiset<K> keys()
Multimap
keys().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()
Multimap
Changes to the returned set will update the underlying multimap, and vice versa. However, adding to the returned set is not possible.
public boolean put(K key, V value)
Multimap
Some 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.
public boolean putAll(K key, Iterable<? extends V> values)
Multimap
values
, 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.
public boolean putAll(Multimap<? extends K,? extends V> multimap)
Multimap
multimap
in this multimap, in the
order returned by multimap.entries()
.public boolean remove(@Nullable Object key, @Nullable Object value)
Multimap
key
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.public Collection<V> removeAll(@Nullable Object key)
Multimap
key
.
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.
public Collection<V> replaceValues(K key, Iterable<? extends V> values)
Multimap
If values
is empty, this is equivalent to
removeAll(key)
.
replaceValues
in interface Multimap<K,V>
public int size()
Multimap
Note: 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()
Multimap
values().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)
Multimap
Multimap.asMap()
,
are also equal.
In general, two multimaps with identical key-value mappings may or may
not be equal, depending on the implementation. For example, two
SetMultimap
instances with the same key-value mappings are equal,
but equality of two ListMultimap
instances depends on the ordering
of the values for each key.
A non-empty SetMultimap
cannot be equal to a non-empty
ListMultimap
, since their Multimap.asMap()
views contain unequal
collections as values. However, any two empty multimaps are equal, because
they both have empty Multimap.asMap()
views.
public int hashCode()
Multimap
The hash code of a multimap is defined as the hash code of the map view,
as returned by Multimap.asMap()
.
In general, two multimaps with identical key-value mappings may or may
not have the same hash codes, depending on the implementation. For
example, two SetMultimap
instances with the same key-value
mappings will have the same hashCode
, but the hashCode
of ListMultimap
instances depends on the ordering of the values
for each key.
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