Package com.google.common.collect
Class EnumMultiset<E extends Enum<E>>
java.lang.Object
java.util.AbstractCollection<E>
com.google.common.collect.AbstractMultiset<E>
com.google.common.collect.EnumMultiset<E>
- All Implemented Interfaces:
Multiset<E>
,Serializable
,Iterable<E>
,Collection<E>
public final class EnumMultiset<E extends Enum<E>>
extends AbstractMultiset<E>
implements Serializable
Multiset implementation specialized for enum elements, supporting all single-element operations
in O(1).
See the Guava User Guide article on Multiset
.
- Since:
- 2.0
- See Also:
-
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 int[]
private int
private E[]
private static final long
private long
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Constructor Summary
Constructors -
Method Summary
Modifier and TypeMethodDescriptionint
Adds a number of occurrences of an element to this multiset.private void
Returnselement
cast toE
, if it actually is a nonnull E.void
clear()
int
Returns the number of occurrences of an element in this multiset (the count of the element).static <E extends Enum<E>>
EnumMultiset<E> Creates an emptyEnumMultiset
.static <E extends Enum<E>>
EnumMultiset<E> Creates a newEnumMultiset
containing the specified elements.static <E extends Enum<E>>
EnumMultiset<E> Returns a newEnumMultiset
instance containing the given elements.(package private) int
(package private) Iterator
<Multiset.Entry<E>> 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 boolean
iterator()
private void
readObject
(ObjectInputStream stream) int
Removes a number of occurrences of the specified element from this multiset.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.private void
writeObject
(ObjectOutputStream stream) Methods inherited from class com.google.common.collect.AbstractMultiset
add, addAll, contains, createElementSet, createEntrySet, elementSet, entrySet, 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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type
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enumConstants
-
counts
private transient int[] counts -
distinctElements
private transient int distinctElements -
size
private transient long size -
serialVersionUID
private static final long serialVersionUID- See Also:
-
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Constructor Details
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EnumMultiset
Creates an emptyEnumMultiset
.
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Method Details
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create
Creates an emptyEnumMultiset
. -
create
Creates a newEnumMultiset
containing the specified elements.This implementation is highly efficient when
elements
is itself aMultiset
.- Parameters:
elements
- the elements that the multiset should contain- Throws:
IllegalArgumentException
- ifelements
is empty
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create
Returns a newEnumMultiset
instance containing the given elements. Unlikecreate(Iterable)
, this method does not produce an exception on an empty iterable.- Since:
- 14.0
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isActuallyE
-
checkIsE
Returnselement
cast toE
, if it actually is a nonnull E. Otherwise, throws either a NullPointerException or a ClassCastException as appropriate. -
distinctElements
int distinctElements()- Specified by:
distinctElements
in classAbstractMultiset<E extends Enum<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()
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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
Description copied from interface:Multiset
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 extends Enum<E>>
- Overrides:
add
in classAbstractMultiset<E extends Enum<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
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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 extends Enum<E>>
- Overrides:
remove
in classAbstractMultiset<E extends Enum<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 extends Enum<E>>
- Overrides:
setCount
in classAbstractMultiset<E extends Enum<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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clear
public void clear()- Specified by:
clear
in interfaceCollection<E extends Enum<E>>
- Specified by:
clear
in classAbstractMultiset<E extends Enum<E>>
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elementIterator
- Specified by:
elementIterator
in classAbstractMultiset<E extends Enum<E>>
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entryIterator
Iterator<Multiset.Entry<E>> entryIterator()- Specified by:
entryIterator
in classAbstractMultiset<E extends Enum<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 extends Enum<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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writeObject
- Throws:
IOException
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readObject
- Throws:
IOException
ClassNotFoundException
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