Class AbstractMapBasedMultiset<E>
- All Implemented Interfaces:
Multiset<E>
,Serializable
,Iterable<E>
,Collection<E>
- Direct Known Subclasses:
HashMultiset
,LinkedHashMultiset
Multiset<E>
backed by an instance of Map<E, Count>
.
For serialization to work, the subclass must specify explicit readObject
and
writeObject
methods.
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Nested Class Summary
Nested ClassesNested classes/interfaces inherited from class com.google.common.collect.AbstractMultiset
AbstractMultiset.ElementSet, AbstractMultiset.EntrySet
Nested classes/interfaces inherited from interface com.google.common.collect.Multiset
Multiset.Entry<E>
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Field Summary
FieldsModifier and TypeFieldDescriptionprivate static final long
private long
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Constructor Summary
ConstructorsModifierConstructorDescriptionprotected
AbstractMapBasedMultiset
(Map<E, Count> backingMap) Standard constructor. -
Method Summary
Modifier and TypeMethodDescriptionint
Adds a number of occurrences of an element to this multiset.void
clear()
int
Returns the number of occurrences of an element in this multiset (the count of the element).(package private) int
(package private) Iterator
<Multiset.Entry<E>> entrySet()
Returns a view of the contents of this multiset, grouped intoMultiset.Entry
instances, each providing an element of the multiset and the count of that element.void
forEachEntry
(ObjIntConsumer<? super E> action) Runs the specified action for each distinct element in this multiset, and the number of occurrences of that element.private static int
iterator()
private void
int
Removes a number of occurrences of the specified element from this multiset.(package private) void
setBackingMap
(Map<E, Count> backingMap) Used during deserialization only.int
Adds or removes the necessary occurrences of an element such that the element attains the desired count.int
size()
Returns the total number of all occurrences of all elements in this multiset.Methods inherited from class com.google.common.collect.AbstractMultiset
add, addAll, contains, createElementSet, createEntrySet, elementSet, equals, hashCode, isEmpty, remove, removeAll, retainAll, setCount, toString
Methods inherited from class java.util.AbstractCollection
containsAll, toArray, toArray
Methods inherited from class java.lang.Object
clone, finalize, getClass, notify, notifyAll, wait, wait, wait
Methods inherited from interface java.util.Collection
parallelStream, removeIf, stream, toArray, toArray, toArray
Methods inherited from interface com.google.common.collect.Multiset
containsAll, forEach, spliterator
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Field Details
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backingMap
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size
private transient long size -
serialVersionUID
private static final long serialVersionUID- See Also:
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Constructor Details
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AbstractMapBasedMultiset
Standard constructor.
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Method Details
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setBackingMap
Used during deserialization only. The backing map must be empty. -
entrySet
Returns a view of the contents of this multiset, grouped intoMultiset.Entry
instances, each providing an element of the multiset and the count of that element. This set contains exactly one entry for each distinct element in the multiset (thus it always has the same size as theMultiset.elementSet()
). The order of the elements in the element set is unspecified.The entry set is backed by the same data as the multiset, so any change to either is immediately reflected in the other. However, multiset changes may or may not be reflected in any
Entry
instances already retrieved from the entry set (this is implementation-dependent). Furthermore, implementations are not required to support modifications to the entry set at all, and theEntry
instances themselves don't even have methods for modification. See the specific implementation class for more details on how its entry set handles modifications.Invoking
Multiset.Entry.getCount()
on an entry in the returned set always returns the current count of that element in the multiset, as opposed to the count at the time the entry was retrieved. -
elementIterator
- Specified by:
elementIterator
in classAbstractMultiset<E>
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entryIterator
Iterator<Multiset.Entry<E>> entryIterator()- Specified by:
entryIterator
in classAbstractMultiset<E>
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forEachEntry
Description copied from interface:Multiset
Runs the specified action for each distinct element in this multiset, and the number of occurrences of that element. For someMultiset
implementations, this may be more efficient than iterating over theMultiset.entrySet()
either explicitly or withentrySet().forEach(action)
.- Specified by:
forEachEntry
in interfaceMultiset<E>
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clear
public void clear()- Specified by:
clear
in interfaceCollection<E>
- Specified by:
clear
in classAbstractMultiset<E>
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distinctElements
int distinctElements()- Specified by:
distinctElements
in classAbstractMultiset<E>
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size
public int size()Description copied from interface:Multiset
Returns the total number of all occurrences of all elements in this multiset.Note: this method does not return the number of distinct elements in the multiset, which is given by
entrySet().size()
.- Specified by:
size
in interfaceCollection<E>
- Specified by:
size
in interfaceMultiset<E>
- Specified by:
size
in classAbstractCollection<E>
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iterator
Description copied from interface:Multiset
Elements that occur multiple times in the multiset will appear multiple times in this iterator, though not necessarily sequentially.
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count
Description copied from interface:Multiset
Returns the number of occurrences of an element in this multiset (the count of the element). Note that for anObject.equals(java.lang.Object)
-based multiset, this gives the same result asCollections.frequency(java.util.Collection<?>, java.lang.Object)
(which would presumably perform more poorly).Note: the utility method
Iterables.frequency(java.lang.Iterable<?>, java.lang.Object)
generalizes this operation; it correctly delegates to this method when dealing with a multiset, but it can also accept any other iterable type. -
add
Adds a number of occurrences of an element to this multiset. Note that ifoccurrences == 1
, this method has the identical effect toMultiset.add(Object)
. This method is functionally equivalent (except in the case of overflow) to the calladdAll(Collections.nCopies(element, occurrences))
, which would presumably perform much more poorly.- Specified by:
add
in interfaceMultiset<E>
- Overrides:
add
in classAbstractMultiset<E>
- Parameters:
element
- the element to add occurrences of; may be null only if explicitly allowed by the implementationoccurrences
- the number of occurrences of the element to add. May be zero, in which case no change will be made.- Returns:
- the count of the element before the operation; possibly zero
- Throws:
IllegalArgumentException
- if the call would result in more thanInteger.MAX_VALUE
occurrences ofelement
in this multiset.
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remove
Description copied from interface:Multiset
Removes a number of occurrences of the specified element from this multiset. If the multiset contains fewer than this number of occurrences to begin with, all occurrences will be removed. Note that ifoccurrences == 1
, this is functionally equivalent to the callremove(element)
.- Specified by:
remove
in interfaceMultiset<E>
- Overrides:
remove
in classAbstractMultiset<E>
- Parameters:
element
- the element to conditionally remove occurrences ofoccurrences
- the number of occurrences of the element to remove. May be zero, in which case no change will be made.- Returns:
- the count of the element before the operation; possibly zero
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setCount
Description copied from interface:Multiset
Adds or removes the necessary occurrences of an element such that the element attains the desired count.- Specified by:
setCount
in interfaceMultiset<E>
- Overrides:
setCount
in classAbstractMultiset<E>
- Parameters:
element
- the element to add or remove occurrences of; may be null only if explicitly allowed by the implementationcount
- the desired count of the element in this multiset- Returns:
- the count of the element before the operation; possibly zero
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getAndSet
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readObjectNoData
- Throws:
ObjectStreamException
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