@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
.
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
.
See the Guava User Guide article on Multimap
.
Modifier and Type | Method and Description |
---|---|
NavigableMap |
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
Returns
true if this multimap contains at least one key-value pair with the key
key and the value
value .
|
boolean |
containsKey(Object
Returns
true if this multimap contains at least one key-value pair with the key
key .
|
boolean |
containsValue(Object
Returns
true if this multimap contains at least one key-value pair with the value
value .
|
static <K extends Comparable |
create()
Creates an empty
TreeMultimap ordered by the natural ordering of its keys and values.
|
static <K |
create(Comparator
Creates an empty
TreeMultimap instance using explicit comparators.
|
static <K extends Comparable |
create(Multimap
Constructs a
TreeMultimap , ordered by the natural ordering of its keys and values, with the same mappings as the specified multimap.
|
Set |
entries()
Returns a view collection of all key-value pairs contained in this multimap, as
Map.Entry instances.
|
boolean |
equals(Object
Compares the specified object to this multimap for equality.
|
NavigableSet |
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 |
keyComparator()
Returns the comparator that orders the multimap keys.
|
Multiset |
keys()
Returns a view collection containing the key from each key-value pair in this multimap,
without collapsing duplicates.
|
NavigableSet |
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
Stores a key-value pair in this multimap for each of
values , all using the same key,
key .
|
boolean |
putAll(Multimap
Stores all key-value pairs of
multimap in this multimap, in the order returned by
multimap.entries() .
|
boolean |
remove(Object
Removes a single key-value pair with the key
key and the value
value from this multimap, if such exists.
|
SortedSet |
removeAll(Object
Removes all values associated with a given key.
|
SortedSet |
replaceValues(K key, Iterable
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 .
|
Comparator |
valueComparator()
Returns the comparator that orders the multimap values, with
null indicating that natural ordering is used.
|
Collection |
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, 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 ordering
valueComparator
- the comparator that determines the value ordering
public 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
public Comparator<? super K> keyComparator()
public Comparator<? super V> valueComparator()
SortedSetMultimap
null
indicating that natural ordering is used.
@GwtIncompatible(value="NavigableSet") public NavigableSet<V> get(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.
@GwtIncompatible(value="NavigableSet") 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.
@GwtIncompatible(value="NavigableMap") 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.
public SortedSet<V> removeAll(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>
public SortedSet<V> replaceValues(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.
public boolean put(K key, V value)
public boolean equals(Objectobject)
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.
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(Objectkey)
Multimap
true
if this multimap contains at least one key-value pair with the key
key
.
public void clear()
Multimap
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(Objectvalue)
Multimap
true
if this multimap contains at least one key-value pair with the value
value
.
public boolean containsEntry(Objectkey, Object value)
Multimap
true
if this multimap contains at least one key-value pair with the key
key
and the value
value
.
public boolean remove(Objectkey, 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 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 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
.
hashCode
in interface
Multimap<K,V>
hashCode
in class
Object
Map.hashCode()
public StringtoString()
toString
on the map returned by
Multimap.asMap()
.