Class Multisets.UnmodifiableMultiset<E>
- java.lang.Object
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- com.google.common.collect.ForwardingObject
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- com.google.common.collect.ForwardingCollection<E>
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- com.google.common.collect.ForwardingMultiset<E>
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- com.google.common.collect.Multisets.UnmodifiableMultiset<E>
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- All Implemented Interfaces:
Multiset<E>
,java.io.Serializable
,java.lang.Iterable<E>
,java.util.Collection<E>
- Direct Known Subclasses:
UnmodifiableSortedMultiset
- Enclosing class:
- Multisets
static class Multisets.UnmodifiableMultiset<E> extends ForwardingMultiset<E> implements java.io.Serializable
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Nested Class Summary
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Nested classes/interfaces inherited from class com.google.common.collect.ForwardingMultiset
ForwardingMultiset.StandardElementSet
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Nested classes/interfaces inherited from interface com.google.common.collect.Multiset
Multiset.Entry<E>
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Field Summary
Fields Modifier and Type Field Description (package private) Multiset<? extends E>
delegate
(package private) java.util.Set<E>
elementSet
(package private) java.util.Set<Multiset.Entry<E>>
entrySet
private static long
serialVersionUID
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Constructor Summary
Constructors Constructor Description UnmodifiableMultiset(Multiset<? extends E> delegate)
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Method Summary
All Methods Instance Methods Concrete Methods Modifier and Type Method Description boolean
add(E element)
Adds a single occurrence of the specified element to this multiset.int
add(E element, int occurences)
Adds a number of occurrences of an element to this multiset.boolean
addAll(java.util.Collection<? extends E> elementsToAdd)
void
clear()
(package private) java.util.Set<E>
createElementSet()
protected Multiset<E>
delegate()
Returns the backing delegate instance that methods are forwarded to.java.util.Set<E>
elementSet()
Returns the set of distinct elements contained in this multiset.java.util.Set<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.java.util.Iterator<E>
iterator()
boolean
remove(java.lang.Object element)
Removes a single occurrence of the specified element from this multiset, if present.int
remove(java.lang.Object element, int occurrences)
Removes a number of occurrences of the specified element from this multiset.boolean
removeAll(java.util.Collection<?> elementsToRemove)
boolean
retainAll(java.util.Collection<?> elementsToRetain)
int
setCount(E element, int count)
Adds or removes the necessary occurrences of an element such that the element attains the desired count.boolean
setCount(E element, int oldCount, int newCount)
Conditionally sets the count of an element to a new value, as described inMultiset.setCount(Object, int)
, provided that the element has the expected current count.-
Methods inherited from class com.google.common.collect.ForwardingMultiset
count, equals, hashCode, standardAdd, standardAddAll, standardClear, standardContains, standardCount, standardEquals, standardHashCode, standardIterator, standardRemove, standardRemoveAll, standardRetainAll, standardSetCount, standardSetCount, standardSize, standardToString
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Methods inherited from class com.google.common.collect.ForwardingCollection
contains, containsAll, isEmpty, size, standardContainsAll, standardIsEmpty, standardToArray, standardToArray, toArray, toArray
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Methods inherited from class com.google.common.collect.ForwardingObject
toString
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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 java.util.Collection
isEmpty, parallelStream, removeIf, size, spliterator, stream, toArray, toArray, toArray
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Methods inherited from interface com.google.common.collect.Multiset
contains, containsAll, toString
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Field Detail
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elementSet
transient java.util.Set<E> elementSet
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entrySet
transient java.util.Set<Multiset.Entry<E>> entrySet
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serialVersionUID
private static final long serialVersionUID
- See Also:
- Constant Field Values
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Method Detail
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delegate
protected Multiset<E> delegate()
Description copied from class:ForwardingObject
Returns the backing delegate instance that methods are forwarded to. Abstract subclasses generally override this method with an abstract method that has a more specific return type, such asForwardingSet.delegate()
. Concrete subclasses override this method to supply the instance being decorated.- Specified by:
delegate
in classForwardingMultiset<E>
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createElementSet
java.util.Set<E> createElementSet()
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elementSet
public java.util.Set<E> elementSet()
Description copied from interface:Multiset
Returns the set of distinct elements contained in this multiset. The element set is backed by the same data as the multiset, so any change to either is immediately reflected in the other. The order of the elements in the element set is unspecified.If the element set supports any removal operations, these necessarily cause all occurrences of the removed element(s) to be removed from the multiset. Implementations are not expected to support the add operations, although this is possible.
A common use for the element set is to find the number of distinct elements in the multiset:
elementSet().size()
.- Specified by:
elementSet
in interfaceMultiset<E>
- Overrides:
elementSet
in classForwardingMultiset<E>
- Returns:
- a view of the set of distinct elements in this multiset
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entrySet
public java.util.Set<Multiset.Entry<E>> entrySet()
Description copied from interface:Multiset
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.
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iterator
public java.util.Iterator<E> 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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add
public boolean add(E element)
Description copied from interface:Multiset
Adds a single occurrence of the specified element to this multiset.This method refines
Collection.add(E)
, which only ensures the presence of the element, to further specify that a successful call must always increment the count of the element, and the overall size of the collection, by one.To both add the element and obtain the previous count of that element, use
add
(element, 1)
instead.- Specified by:
add
in interfacejava.util.Collection<E>
- Specified by:
add
in interfaceMultiset<E>
- Overrides:
add
in classForwardingCollection<E>
- Parameters:
element
- the element to add one occurrence of; may be null only if explicitly allowed by the implementation- Returns:
true
always, since this call is required to modify the multiset, unlike otherCollection
types
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add
public int add(E element, int occurences)
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>
- Overrides:
add
in classForwardingMultiset<E>
- Parameters:
element
- the element to add occurrences of; may be null only if explicitly allowed by the implementationoccurences
- 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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addAll
public boolean addAll(java.util.Collection<? extends E> elementsToAdd)
- Specified by:
addAll
in interfacejava.util.Collection<E>
- Overrides:
addAll
in classForwardingCollection<E>
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remove
public boolean remove(java.lang.Object element)
Description copied from interface:Multiset
Removes a single occurrence of the specified element from this multiset, if present.This method refines
Collection.remove(java.lang.Object)
to further specify that it may not throw an exception in response toelement
being null or of the wrong type.To both remove the element and obtain the previous count of that element, use
remove
(element, 1)
instead.
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remove
public int remove(java.lang.Object element, int occurrences)
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 classForwardingMultiset<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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removeAll
public boolean removeAll(java.util.Collection<?> elementsToRemove)
Description copied from interface:Multiset
Note: This method ignores how often any element might appear in
c
, and only cares whether or not an element appears at all. If you wish to remove one occurrence in this multiset for every occurrence inc
, seeMultisets.removeOccurrences(Multiset, Multiset)
.This method refines
Collection.removeAll(java.util.Collection<?>)
to further specify that it may not throw an exception in response to any ofelements
being null or of the wrong type.
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retainAll
public boolean retainAll(java.util.Collection<?> elementsToRetain)
Description copied from interface:Multiset
Note: This method ignores how often any element might appear in
c
, and only cares whether or not an element appears at all. If you wish to remove one occurrence in this multiset for every occurrence inc
, seeMultisets.retainOccurrences(Multiset, Multiset)
.This method refines
Collection.retainAll(java.util.Collection<?>)
to further specify that it may not throw an exception in response to any ofelements
being null or of the wrong type.- Specified by:
retainAll
in interfacejava.util.Collection<E>
- Specified by:
retainAll
in interfaceMultiset<E>
- Overrides:
retainAll
in classForwardingCollection<E>
- See Also:
Multisets.retainOccurrences(Multiset, Multiset)
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clear
public void clear()
- Specified by:
clear
in interfacejava.util.Collection<E>
- Overrides:
clear
in classForwardingCollection<E>
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setCount
public int setCount(E element, int count)
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 classForwardingMultiset<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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setCount
public boolean setCount(E element, int oldCount, int newCount)
Description copied from interface:Multiset
Conditionally sets the count of an element to a new value, as described inMultiset.setCount(Object, int)
, provided that the element has the expected current count. If the current count is notoldCount
, no change is made.- Specified by:
setCount
in interfaceMultiset<E>
- Overrides:
setCount
in classForwardingMultiset<E>
- Parameters:
element
- the element to conditionally set the count of; may be null only if explicitly allowed by the implementationoldCount
- the expected present count of the element in this multisetnewCount
- the desired count of the element in this multiset- Returns:
true
if the condition for modification was met. This implies that the multiset was indeed modified, unlessoldCount == newCount
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