@GwtCompatible(serializable=true, emulated=true) public class TreeMultimap<K,V> extends Object
Multimap
whose keys and values are ordered by their natural ordering or
by supplied comparators. In all cases, this implementation uses Comparable.compareTo(T)
or
Comparator.compare(T, T)
instead of Object.equals(java.lang.Object)
to determine equivalence of
instances.
Warning: The comparators or comparables used must be consistent with equals as
explained by the Comparable
class specification. Otherwise, the resulting multiset will
violate the general contract of SetMultimap
, which it is specified in terms of Object.equals(java.lang.Object)
.
The collections returned by keySet
and asMap
iterate through the keys
according to the key comparator ordering or the natural ordering of the keys. Similarly, get
, removeAll
, and replaceValues
return collections that iterate through the
values according to the value comparator ordering or the natural ordering of the values. The
collections generated by entries
, keys
, and values
iterate across the
keys according to the above key ordering, and for each key they iterate across the values
according to the value ordering.
The multimap does not store duplicate key-value pairs. Adding a new key-value pair equal to an existing key-value pair has no effect.
Null keys and values are permitted (provided, of course, that the respective comparators support them). All optional multimap methods are supported, and all returned views are modifiable.
This class is not threadsafe when any concurrent operations update the multimap. Concurrent
read operations will work correctly. To allow concurrent update operations, wrap your multimap
with a call to Multimaps.synchronizedSortedSetMultimap(com.google.common.collect.SortedSetMultimap<K, V>)
.
See the Guava User Guide article on Multimap
.
Modifier and Type | Method and Description |
---|---|
NavigableMap<K,Collection<V>> |
asMap()
Returns a map view that associates each key with the corresponding values in the multimap.
|
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 . |
static <K extends Comparable,V extends Comparable> |
create()
Creates an empty
TreeMultimap ordered by the natural ordering of its keys and values. |
static <K,V> TreeMultimap<K,V> |
create(Comparator<? super K> keyComparator,
Comparator<? super V> valueComparator)
Creates an empty
TreeMultimap instance using explicit comparators. |
static <K extends Comparable,V extends Comparable> |
create(Multimap<? extends K,? extends V> multimap)
Constructs a
TreeMultimap , ordered by the natural ordering of its keys and values, with
the same mappings as the specified multimap. |
Set<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 to this multimap for equality.
|
void |
forEach(BiConsumer<? super K,? super V> action)
Performs the given action for all key-value pairs contained in this multimap.
|
NavigableSet<V> |
get(K key)
Returns a collection view of all values associated with a key.
|
int |
hashCode()
Returns the hash code for this multimap.
|
boolean |
isEmpty()
Returns
true if this multimap contains no key-value pairs. |
Comparator<? super K> |
keyComparator()
Deprecated.
Use
((NavigableSet<K>) multimap.keySet()).comparator() instead. |
Multiset<K> |
keys()
Returns a view collection containing the key from each key-value pair in this multimap,
without collapsing duplicates.
|
NavigableSet<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 the 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. |
SortedSet<V> |
removeAll(Object key)
Removes all values associated with a given key.
|
SortedSet<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.
|
String |
toString()
Returns a string representation of the multimap, generated by calling
toString on the
map returned by Multimap.asMap() . |
Comparator<? super V> |
valueComparator()
Returns the comparator that orders the multimap values, with
null indicating that
natural ordering is used. |
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() ). |
clone, finalize, getClass, notify, notifyAll, wait, wait, wait
entries, equals
clear, containsEntry, containsKey, containsValue, forEach, hashCode, isEmpty, keys, put, putAll, putAll, remove, size
public static <K extends Comparable,V extends Comparable> TreeMultimap<K,V> create()
TreeMultimap
ordered by the natural ordering of its keys and values.public static <K,V> TreeMultimap<K,V> create(Comparator<? super K> keyComparator, Comparator<? super V> valueComparator)
TreeMultimap
instance using explicit comparators. Neither comparator
may be null; use Ordering.natural()
to specify natural order.keyComparator
- the comparator that determines the key orderingvalueComparator
- the comparator that determines the value orderingpublic static <K extends Comparable,V extends Comparable> TreeMultimap<K,V> create(Multimap<? extends K,? extends V> multimap)
TreeMultimap
, ordered by the natural ordering of its keys and values, with
the same mappings as the specified multimap.multimap
- the multimap whose contents are copied to this multimap@Deprecated public Comparator<? super K> keyComparator()
((NavigableSet<K>) multimap.keySet()).comparator()
instead.public Comparator<? super V> valueComparator()
SortedSetMultimap
null
indicating that
natural ordering is used.@GwtIncompatible public NavigableSet<V> get(@NullableDecl K key)
Changes to the returned collection will update the underlying multimap, and vice versa.
Because a SortedSetMultimap
has unique sorted values for a given key, this method
returns a SortedSet
, instead of the Collection
specified in the Multimap
interface.
public NavigableSet<K> keySet()
Changes to the returned set will update the underlying multimap, and vice versa. However, adding to the returned set is not possible.
Because a TreeMultimap
has unique sorted keys, this method returns a NavigableSet
, instead of the Set
specified in the Multimap
interface.
public NavigableMap<K,Collection<V>> asMap()
setValue
on its entries, put
, or putAll
.
When passed a key that is present in the map, asMap().get(Object)
has the same
behavior as get(K)
, returning a live collection. When passed a key that is not present,
however, asMap().get(Object)
returns null
instead of an empty collection.
Though the method signature doesn't say so explicitly, the returned map has SortedSet
values.
Because a TreeMultimap
has unique sorted keys, this method returns a NavigableMap
, instead of the Map
specified in the Multimap
interface.
@CanIgnoreReturnValue public SortedSet<V> removeAll(@NullableDecl Object key)
Because a SortedSetMultimap
has unique sorted values for a given key, this method
returns a SortedSet
, instead of the Collection
specified in the Multimap
interface.
removeAll
in interface Multimap<K,V>
removeAll
in interface SetMultimap<K,V>
removeAll
in interface SortedSetMultimap<K,V>
@CanIgnoreReturnValue public SortedSet<V> replaceValues(@NullableDecl K key, Iterable<? extends V> values)
Because a SortedSetMultimap
has unique sorted values for a given key, this method
returns a SortedSet
, instead of the Collection
specified in the Multimap
interface.
Any duplicates in values
will be stored in the multimap once.
replaceValues
in interface Multimap<K,V>
replaceValues
in interface SetMultimap<K,V>
replaceValues
in interface SortedSetMultimap<K,V>
public Collection<V> values()
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.
The iterator generated by the returned collection traverses the values for one key, followed by the values of a second key, and so on.
Consequently, the values do not follow their natural ordering or the ordering of the value comparator.
public Set<Map.Entry<K,V>> entries()
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.
The iterator generated by the returned collection traverses the values for one key, followed by the values of a second key, and so on.
Each entry is an immutable snapshot of a key-value mapping in the multimap, taken at the time the entry is returned by a method call to the collection or its iterator.
Because a SetMultimap
has unique values for a given key, this method returns a
Set
, instead of the Collection
specified in the Multimap
interface.
entries
in interface Multimap<K,V>
entries
in interface SetMultimap<K,V>
@CanIgnoreReturnValue public boolean put(@NullableDecl K key, @NullableDecl V value)
public boolean equals(@NullableDecl Object object)
Two SetMultimap
instances are equal if, for each key, they contain the same values.
Equality does not depend on the ordering of keys or values.
equals
in interface Multimap<K,V>
equals
in interface SetMultimap<K,V>
object
- the reference object with which to compare.true
if this object is the same as the obj
argument; false
otherwise.Object.hashCode()
,
HashMap
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 boolean containsKey(@NullableDecl 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 void clear()
Multimap
public void forEach(BiConsumer<? super K,? super V> action)
Multimap
Multimap
implementation, actions will be performed in the order of
iteration of Multimap.entries()
. Exceptions thrown by the action are relayed to the caller.
To loop over all keys and their associated value collections, write Multimaps.asMap(multimap).forEach((key, valueCollection) -> action())
.
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 boolean containsValue(@NullableDecl 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 boolean containsEntry(@NullableDecl Object key, @NullableDecl 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>
@CanIgnoreReturnValue public boolean remove(@NullableDecl Object key, @NullableDecl 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.@CanIgnoreReturnValue public boolean putAll(@NullableDecl 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.
@CanIgnoreReturnValue public boolean putAll(Multimap<? extends K,? extends V> multimap)
Multimap
multimap
in this multimap, in the order returned by
multimap.entries()
.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 int hashCode()
The hash code of a multimap is defined as the hash code of the map view, as returned by
Multimap.asMap()
.
hashCode
in interface Multimap<K,V>
hashCode
in class Object
Map.hashCode()
public String toString()
toString
on the
map returned by Multimap.asMap()
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