Class LinkedListMultimap<K,V>
- java.lang.Object
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- com.google.common.collect.AbstractMultimap<K,V>
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- com.google.common.collect.LinkedListMultimap<K,V>
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- All Implemented Interfaces:
ListMultimap<K,V>
,Multimap<K,V>
,java.io.Serializable
@GwtCompatible(serializable=true, emulated=true) public class LinkedListMultimap<K,V> extends AbstractMultimap<K,V> implements ListMultimap<K,V>, java.io.Serializable
An implementation ofListMultimap
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);
AbstractMultimap.keys()
is[key1, key2, key1]
, and similarly forentries()
. UnlikeLinkedHashMultimap
, 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]
. Theentries()
iterator returns mutable map entries, andreplaceValues(K, java.lang.Iterable<? extends V>)
attempts to preserve iteration order as much as possible.The collections returned by
AbstractMultimap.keySet()
andAbstractMultimap.asMap
iterate through the keys in the order they were first added to the multimap. Similarly,get(K)
,removeAll(java.lang.Object)
, andreplaceValues(K, java.lang.Iterable<? extends V>)
return collections that iterate through the values in the order they were added. The collections generated byentries()
,AbstractMultimap.keys()
, andvalues()
iterate across the key-value mappings in the order they were added to the multimap.The
values()
andentries()
methods both return aList
, instead of theCollection
specified by theListMultimap
interface.The methods
get(K)
,AbstractMultimap.keySet()
,AbstractMultimap.keys()
,values()
,entries()
, andAbstractMultimap.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
.- Since:
- 2.0
- See Also:
- Serialized Form
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Nested Class Summary
Nested Classes Modifier and Type Class Description private class
LinkedListMultimap.DistinctKeyIterator
AnIterator
over distinct keys in key head order.private static class
LinkedListMultimap.KeyList<K,V>
private static class
LinkedListMultimap.Node<K,V>
private class
LinkedListMultimap.NodeIterator
AnIterator
over all nodes.private class
LinkedListMultimap.ValueForKeyIterator
AListIterator
over values for a specified key.-
Nested classes/interfaces inherited from class com.google.common.collect.AbstractMultimap
AbstractMultimap.Values
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Field Summary
Fields Modifier and Type Field Description private LinkedListMultimap.Node<K,V>
head
private java.util.Map<K,LinkedListMultimap.KeyList<K,V>>
keyToKeyList
private int
modCount
private static long
serialVersionUID
private int
size
private LinkedListMultimap.Node<K,V>
tail
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Constructor Summary
Constructors Modifier Constructor Description (package private)
LinkedListMultimap()
private
LinkedListMultimap(int expectedKeys)
private
LinkedListMultimap(Multimap<? extends K,? extends V> multimap)
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Method Summary
All Methods Static Methods Instance Methods Concrete Methods Modifier and Type Method Description private LinkedListMultimap.Node<K,V>
addNode(K key, V value, LinkedListMultimap.Node<K,V> nextSibling)
Adds a new node for the specified key-value pair before the specifiednextSibling
element, or at the end of the list ifnextSibling
is null.private static void
checkElement(java.lang.Object node)
Helper method for verifying that an iterator element is present.void
clear()
Removes all key-value pairs from the multimap, leaving it empty.boolean
containsKey(java.lang.Object key)
Returnstrue
if this multimap contains at least one key-value pair with the keykey
.boolean
containsValue(java.lang.Object value)
Returnstrue
if this multimap contains at least one key-value pair with the valuevalue
.static <K,V>
LinkedListMultimap<K,V>create()
Creates a new, emptyLinkedListMultimap
with the default initial capacity.static <K,V>
LinkedListMultimap<K,V>create(int expectedKeys)
Constructs an emptyLinkedListMultimap
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 aLinkedListMultimap
with the same mappings as the specifiedMultimap
.(package private) java.util.Map<K,java.util.Collection<V>>
createAsMap()
(package private) java.util.List<java.util.Map.Entry<K,V>>
createEntries()
(package private) java.util.Set<K>
createKeySet()
(package private) java.util.List<V>
createValues()
java.util.List<java.util.Map.Entry<K,V>>
entries()
Returns a view collection of all key-value pairs contained in this multimap, asMap.Entry
instances.(package private) java.util.Iterator<java.util.Map.Entry<K,V>>
entryIterator()
java.util.List<V>
get(K key)
Returns a view collection of the values associated withkey
in this multimap, if any.private java.util.List<V>
getCopy(java.lang.Object key)
boolean
isEmpty()
Returnstrue
if this multimap contains no key-value pairs.boolean
put(K key, V value)
Stores a key-value pair in the multimap.private void
readObject(java.io.ObjectInputStream stream)
java.util.List<V>
removeAll(java.lang.Object key)
Removes all values associated with the keykey
.private void
removeAllNodes(java.lang.Object key)
Removes all nodes for the specified key.private void
removeNode(LinkedListMultimap.Node<K,V> node)
Removes the specified node from the linked list.java.util.List<V>
replaceValues(K key, java.lang.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.java.util.List<V>
values()
Returns a view collection containing the value from each key-value pair contained in this multimap, without collapsing duplicates (sovalues().size() == size()
).private void
writeObject(java.io.ObjectOutputStream stream)
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Methods inherited from class com.google.common.collect.AbstractMultimap
asMap, containsEntry, createKeys, equals, hashCode, keys, keySet, putAll, putAll, remove, toString, valueIterator
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Methods inherited from class java.lang.Object
clone, finalize, getClass, notify, notifyAll, wait, wait, wait
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Methods inherited from interface com.google.common.collect.ListMultimap
asMap, equals
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Field Detail
-
head
private transient LinkedListMultimap.Node<K,V> head
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tail
private transient LinkedListMultimap.Node<K,V> tail
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keyToKeyList
private transient java.util.Map<K,LinkedListMultimap.KeyList<K,V>> keyToKeyList
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size
private transient int size
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modCount
private transient int modCount
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serialVersionUID
@GwtIncompatible private static final long serialVersionUID
- See Also:
- Constant Field Values
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Method Detail
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create
public static <K,V> LinkedListMultimap<K,V> create()
Creates a new, emptyLinkedListMultimap
with the default initial capacity.
-
create
public static <K,V> LinkedListMultimap<K,V> create(int expectedKeys)
Constructs an emptyLinkedListMultimap
with enough capacity to hold the specified number of keys without rehashing.- Parameters:
expectedKeys
- the expected number of distinct keys- Throws:
java.lang.IllegalArgumentException
- ifexpectedKeys
is negative
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create
public static <K,V> LinkedListMultimap<K,V> create(Multimap<? extends K,? extends V> multimap)
Constructs aLinkedListMultimap
with the same mappings as the specifiedMultimap
. The new multimap has the sameMultimap.entries()
iteration order as the input multimap.- Parameters:
multimap
- the multimap whose contents are copied to this multimap
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addNode
private LinkedListMultimap.Node<K,V> addNode(@Nullable K key, @Nullable V value, @Nullable LinkedListMultimap.Node<K,V> nextSibling)
Adds a new node for the specified key-value pair before the specifiednextSibling
element, or at the end of the list ifnextSibling
is null. Note: ifnextSibling
is specified, it MUST be for an node for the samekey
!
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removeNode
private void removeNode(LinkedListMultimap.Node<K,V> node)
Removes the specified node from the linked list. This method is only intended to be used from theIterator
classes. See alsoremoveAllNodes(Object)
.
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removeAllNodes
private void removeAllNodes(@Nullable java.lang.Object key)
Removes all nodes for the specified key.
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checkElement
private static void checkElement(@Nullable java.lang.Object node)
Helper method for verifying that an iterator element is present.
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size
public int size()
Description copied from interface:Multimap
Returns the number of key-value pairs in this multimap.Note: this method does not return the number of distinct keys in the multimap, which is given by
keySet().size()
orasMap().size()
. See the opening section of theMultimap
class documentation for clarification.
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isEmpty
public boolean isEmpty()
Description copied from interface:Multimap
Returnstrue
if this multimap contains no key-value pairs. Equivalent tosize() == 0
, but can in some cases be more efficient.
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containsKey
public boolean containsKey(@Nullable java.lang.Object key)
Description copied from interface:Multimap
Returnstrue
if this multimap contains at least one key-value pair with the keykey
.- Specified by:
containsKey
in interfaceMultimap<K,V>
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containsValue
public boolean containsValue(@Nullable java.lang.Object value)
Description copied from interface:Multimap
Returnstrue
if this multimap contains at least one key-value pair with the valuevalue
.- Specified by:
containsValue
in interfaceMultimap<K,V>
- Overrides:
containsValue
in classAbstractMultimap<K,V>
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put
public boolean put(@Nullable K key, @Nullable V value)
Stores a key-value pair in the multimap.
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replaceValues
public java.util.List<V> replaceValues(@Nullable K key, java.lang.Iterable<? extends V> values)
Stores a collection of values with the same key, replacing any existing values for that key.If
values
is empty, this is equivalent toremoveAll(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
.- Specified by:
replaceValues
in interfaceListMultimap<K,V>
- Specified by:
replaceValues
in interfaceMultimap<K,V>
- Overrides:
replaceValues
in classAbstractMultimap<K,V>
- Returns:
- the collection of replaced values, or an empty collection if no values were previously associated with the key. The collection may be modifiable, but updating it will have no effect on the multimap.
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getCopy
private java.util.List<V> getCopy(@Nullable java.lang.Object key)
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removeAll
public java.util.List<V> removeAll(@Nullable java.lang.Object key)
Removes all values associated with the keykey
.Once this method returns,
key
will not be mapped to any values, so it will not appear inMultimap.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 theCollection
specified in theMultimap
interface.The returned list is immutable and implements
RandomAccess
.
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clear
public void clear()
Description copied from interface:Multimap
Removes all key-value pairs from the multimap, leaving it empty.
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get
public java.util.List<V> get(@Nullable K key)
Returns a view collection of the values associated withkey
in this multimap, if any. Note that whencontainsKey(key)
is false, this returns an empty collection, notnull
.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 theCollection
specified in theMultimap
interface.If the multimap is modified while an iteration over the list is in progress (except through the iterator's own
add
,set
orremove
operations) the results of the iteration are undefined.The returned list is not serializable and does not have random access.
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createKeySet
java.util.Set<K> createKeySet()
- Overrides:
createKeySet
in classAbstractMultimap<K,V>
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values
public java.util.List<V> values()
Returns a view collection containing the value from each key-value pair contained in this multimap, without collapsing duplicates (sovalues().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 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 theCollection
specified in theListMultimap
interface.
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createValues
java.util.List<V> createValues()
- Overrides:
createValues
in classAbstractMultimap<K,V>
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entries
public java.util.List<java.util.Map.Entry<K,V>> entries()
Returns a view collection of all key-value pairs contained in this multimap, asMap.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 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 theCollection
specified in theListMultimap
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, andMap.Entry.setValue(V)
modifies that value. Removing the mapping from the multimap does not alter the value returned bygetValue()
, though a subsequentsetValue()
call won't update the multimap but will lead to a revised value being returned bygetValue()
.
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createEntries
java.util.List<java.util.Map.Entry<K,V>> createEntries()
- Overrides:
createEntries
in classAbstractMultimap<K,V>
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entryIterator
java.util.Iterator<java.util.Map.Entry<K,V>> entryIterator()
- Specified by:
entryIterator
in classAbstractMultimap<K,V>
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createAsMap
java.util.Map<K,java.util.Collection<V>> createAsMap()
- Specified by:
createAsMap
in classAbstractMultimap<K,V>
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writeObject
@GwtIncompatible private void writeObject(java.io.ObjectOutputStream stream) throws java.io.IOException
- Throws:
java.io.IOException
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readObject
@GwtIncompatible private void readObject(java.io.ObjectInputStream stream) throws java.io.IOException, java.lang.ClassNotFoundException
- Throws:
java.io.IOException
java.lang.ClassNotFoundException
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