@GwtCompatible(serializable=true, emulated=true) public class LinkedListMultimap<K,V> extends Object implements ListMultimap<K,V>, Serializable
ListMultimap that supports deterministic
iteration order for both keys and values. The iteration order is preserved
across non-distinct key values. For example, for the following multimap
definition: Multimap<K, V> multimap = LinkedListMultimap.create();
multimap.put(key1, foo);
multimap.put(key2, bar);
multimap.put(key1, baz);
... the iteration order for keys() is [key1, key2, key1],
and similarly for entries(). Unlike LinkedHashMultimap, the
iteration order is kept consistent between keys, entries and values. For
example, calling: map.remove(key1, foo);
changes the entries iteration order to [key2=bar, key1=baz] and the
key iteration order to [key2, key1]. The entries() iterator
returns mutable map entries, and replaceValues(K, java.lang.Iterable<? extends V>) attempts to preserve
iteration order as much as possible.
The collections returned by keySet() and asMap iterate
through the keys in the order they were first added to the multimap.
Similarly, get(K), removeAll(java.lang.Object), and replaceValues(K, java.lang.Iterable<? extends V>)
return collections that iterate through the values in the order they were
added. The collections generated by entries(), keys(), and
values() iterate across the key-value mappings in the order they were
added to the multimap.
The values() and entries() methods both return a
List, instead of the Collection specified by the ListMultimap interface.
The methods get(K), keySet(), keys(),
values(), entries(), and asMap return collections
that are views of the multimap. If the multimap is modified while an
iteration over any of those collections is in progress, except through the
iterator's methods, the results of the iteration are undefined.
Keys and values may be null. 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.synchronizedListMultimap(com.google.common.collect.ListMultimap<K, V>).
See the Guava User Guide article on
Multimap.
| Modifier and Type | Method and Description |
|---|---|
Map<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.
|
boolean |
containsEntry(Object key,
Object value)
Returns
true if the multimap contains the specified key-value pair. |
boolean |
containsKey(Object key)
Returns
true if the multimap contains any values for the specified
key. |
boolean |
containsValue(Object value)
Returns
true if the multimap contains the specified value for any
key. |
static <K,V> LinkedListMultimap<K,V> |
create()
Creates a new, empty
LinkedListMultimap with the default initial
capacity. |
static <K,V> LinkedListMultimap<K,V> |
create(int expectedKeys)
Constructs an empty
LinkedListMultimap with enough capacity to hold
the specified number of keys without rehashing. |
static <K,V> LinkedListMultimap<K,V> |
create(Multimap<? extends K,? extends V> multimap)
Constructs a
LinkedListMultimap with the same mappings as the
specified Multimap. |
List<Map.Entry<K,V>> |
entries()
Returns a collection of all key-value pairs.
|
boolean |
equals(Object object)
Indicates whether some other object is "equal to" this one.
|
List<V> |
get(K key)
Returns a collection view containing the values associated with
key
in this multimap, if any. |
int |
hashCode()
Returns the hash code for this multimap.
|
boolean |
isEmpty()
Returns
true if the multimap contains no key-value pairs. |
Multiset<K> |
keys()
Returns a collection, which may contain duplicates, of all keys.
|
Set<K> |
keySet()
Returns the set of all keys, each appearing once in the returned set.
|
boolean |
put(K key,
V value)
Stores a key-value pair in the multimap.
|
boolean |
putAll(K key,
Iterable<? extends V> values)
Stores key-value pairs in this multimap with one key and multiple values.
|
boolean |
putAll(Multimap<? extends K,? extends V> multimap)
Copies all of another multimap's key-value pairs into this multimap.
|
boolean |
remove(Object key,
Object value)
Removes a single key-value pair from the multimap.
|
List<V> |
removeAll(Object key)
Removes all values associated with a given key.
|
List<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 the multimap.
|
String |
toString()
Returns a string representation of the multimap, generated by calling
toString on the map returned by Multimap.asMap(). |
List<V> |
values()
Returns a collection of all values in the multimap.
|
clone, finalize, getClass, notify, notifyAll, wait, wait, waitasMap, equalspublic static <K,V> LinkedListMultimap<K,V> create()
LinkedListMultimap with the default initial
capacity.public static <K,V> LinkedListMultimap<K,V> create(int expectedKeys)
LinkedListMultimap with enough capacity to hold
the specified number of keys without rehashing.expectedKeys - the expected number of distinct keysIllegalArgumentException - if expectedKeys is negativepublic static <K,V> LinkedListMultimap<K,V> create(Multimap<? extends K,? extends V> multimap)
LinkedListMultimap with the same mappings as the
specified Multimap. The new multimap has the same
Multimap.entries() iteration order as the input multimap.multimap - the multimap whose contents are copied to this multimappublic int size()
Multimappublic boolean isEmpty()
Multimaptrue if the multimap contains no key-value pairs.public boolean containsKey(@Nullable Object key)
Multimaptrue if the multimap contains any values for the specified
key.containsKey in interface Multimap<K,V>key - key to search for in multimappublic boolean containsValue(@Nullable Object value)
Multimaptrue if the multimap contains the specified value for any
key.containsValue in interface Multimap<K,V>value - value to search for in multimappublic List<V> replaceValues(@Nullable K key, Iterable<? extends V> values)
If values is empty, this is equivalent to
removeAll(key).
If any entries for the specified key already exist in the
multimap, their values are changed in-place without affecting the iteration
order.
The returned list is immutable and implements
RandomAccess.
replaceValues in interface ListMultimap<K,V>replaceValues in interface Multimap<K,V>key - key to store in the multimapvalues - values to store in the multimappublic List<V> removeAll(@Nullable Object 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.
Because the values for a given key may have duplicates and follow the
insertion ordering, this method returns a List, instead of the
Collection specified in the Multimap interface.
The returned list is immutable and implements
RandomAccess.
removeAll in interface ListMultimap<K,V>removeAll in interface Multimap<K,V>key - key of entries to remove from the multimappublic void clear()
Multimappublic List<V> get(@Nullable K key)
key
in this multimap, if any. Note that even when (containsKey(key) is
false, get(key) still returns an empty collection, not null.
Changes to the returned collection will update the underlying multimap, and vice versa.
Because the values for a given key may have duplicates and follow the
insertion ordering, this method returns a List, instead of the
Collection specified in the Multimap interface.
If the multimap is modified while an iteration over the list is in
progress (except through the iterator's own add, set or
remove operations) the results of the iteration are undefined.
The returned list is not serializable and does not have random access.
public List<V> values()
The iterator generated by the returned collection traverses the values
in the order they were added to the multimap. Because the values may have
duplicates and follow the insertion ordering, this method returns a List, instead of the Collection specified in the ListMultimap interface.
public List<Map.Entry<K,V>> entries()
add or addAll operations.
The iterator generated by the returned collection traverses the entries
in the order they were added to the multimap. Because the entries may have
duplicates and follow the insertion ordering, this method returns a List, instead of the Collection specified in the ListMultimap interface.
An entry's Map.Entry.getKey() method always returns the same key,
regardless of what happens subsequently. As long as the corresponding
key-value mapping is not removed from the multimap, Map.Entry.getValue()
returns the value from the multimap, which may change over time, and Map.Entry.setValue(V) modifies that value. Removing the mapping from the
multimap does not alter the value returned by getValue(), though a
subsequent setValue() call won't update the multimap but will lead
to a revised value being returned by getValue().
public boolean containsEntry(@Nullable Object key, @Nullable Object value)
Multimaptrue if the multimap contains the specified key-value pair.containsEntry in interface Multimap<K,V>key - key to search for in multimapvalue - value to search for in multimappublic boolean remove(@Nullable Object key, @Nullable Object value)
Multimappublic boolean putAll(@Nullable K key, Iterable<? extends V> values)
MultimapThis is equivalent to
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)
Multimapmultimap.entries().public Set<K> keySet()
MultimapNote that the key set contains a key if and only if this multimap maps that key to at least one value.
public Multiset<K> keys()
Multimappublic Map<K,Collection<V>> asMap()
MultimapsetValue()
on its entries, put, or putAll.
When passed a key that is present in the map, asMap().get(Object) has the same behavior as Multimap.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.
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()
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 ObjectMap.hashCode()public String toString()
toString on the map returned by Multimap.asMap().Copyright © 2010-2013. All Rights Reserved.