Package org.apache.commons.collections4.multiset

Class UnmodifiableMultiSet<E>

java.lang.Object

org.apache.commons.collections4.collection.AbstractCollectionDecorator<E>

org.apache.commons.collections4.multiset.AbstractMultiSetDecorator<E>

org.apache.commons.collections4.multiset.UnmodifiableMultiSet<E>

Type Parameters:

E - the type held in the multiset

All Implemented Interfaces:

Serializable, Iterable<E>, Collection<E>, MultiSet<E>, Unmodifiable

public final class UnmodifiableMultiSet<E>
extends AbstractMultiSetDecorator<E>
implements Unmodifiable

Decorates another MultiSet to ensure it can't be altered.

Attempts to modify it will result in an UnsupportedOperationException.

Since:

4.1

See Also:

Serialized Form

Nested Class Summary

Nested classes/interfaces inherited from interface org.apache.commons.collections4.MultiSet

MultiSet.Entry<E>

Method Summary

Modifier and Type	Method	Description
boolean	add(E object)	Adds one copy of the specified object to the MultiSet.
int	add(E object, int count)	Adds a number of occurrences of the specified object to the MultiSet.
boolean	addAll(Collection<? extends E> coll)
void	clear()
Set<MultiSet.Entry<E>>	entrySet()	Returns a Set of all entries contained in the MultiSet.
Iterator<E>	iterator()	Returns an Iterator over the entire set of members, including copies due to cardinality.
boolean	remove(Object object)	Removes one occurrence of the given object from the MultiSet.
int	remove(Object object, int count)	Removes a number of occurrences of the specified object from the MultiSet.
boolean	removeAll(Collection<?> coll)	Remove all occurrences of all elements from this MultiSet represented in the given collection.
boolean	retainAll(Collection<?> coll)	Remove any elements of this MultiSet that are not contained in the given collection.
int	setCount(E object, int count)	Sets the number of occurrences of the specified object in the MultiSet to the given count.
Set<E>	uniqueSet()	Returns a Set of unique elements in the MultiSet.
static <E> MultiSet<E>	unmodifiableMultiSet(MultiSet<? extends E> multiset)	Factory method to create an unmodifiable multiset.

Methods inherited from class org.apache.commons.collections4.multiset.AbstractMultiSetDecorator

decorated, equals, getCount, hashCode

Methods inherited from class org.apache.commons.collections4.collection.AbstractCollectionDecorator

contains, containsAll, isEmpty, setCollection, size, toArray, toArray, toString

Methods inherited from class java.lang.Object

clone, finalize, getClass, notify, notifyAll, wait, wait, wait

Methods inherited from interface java.util.Collection

contains, isEmpty, parallelStream, removeIf, spliterator, stream, toArray, toArray, toArray

Methods inherited from interface java.lang.Iterable

forEach

Methods inherited from interface org.apache.commons.collections4.MultiSet

containsAll, size

Method Detail

unmodifiableMultiSet

public static <E> MultiSet<E> unmodifiableMultiSet(MultiSet<? extends E> multiset)

Factory method to create an unmodifiable multiset.

If the multiset passed in is already unmodifiable, it is returned.

Type Parameters:

E - the type of the elements in the multiset

Parameters:

multiset - the multiset to decorate, may not be null

Returns:

an unmodifiable MultiSet

Throws:

NullPointerException - if multiset is null

iterator

public Iterator<E> iterator()

Description copied from interface: MultiSet

Returns an Iterator over the entire set of members, including copies due to cardinality. This iterator is fail-fast and will not tolerate concurrent modifications.

Specified by:

iterator in interface Collection<E>

Specified by:

iterator in interface Iterable<E>

Specified by:

iterator in interface MultiSet<E>

Overrides:

iterator in class AbstractCollectionDecorator<E>

Returns:

iterator over all elements in the MultiSet

add

public boolean add(E object)

Description copied from interface: MultiSet

Adds one copy of the specified object to the MultiSet.

If the object is already in the MultiSet.uniqueSet() then increment its count as reported by MultiSet.getCount(Object). Otherwise add it to the MultiSet.uniqueSet() and report its count as 1.

Specified by:

add in interface Collection<E>

Specified by:

add in interface MultiSet<E>

Overrides:

add in class AbstractCollectionDecorator<E>

Parameters:

object - the object to add

Returns:

true always, as the size of the MultiSet is increased in any case

addAll

public boolean addAll(Collection<? extends E> coll)

Specified by:

addAll in interface Collection<E>

Overrides:

addAll in class AbstractCollectionDecorator<E>

clear

public void clear()

Specified by:

clear in interface Collection<E>

Overrides:

clear in class AbstractCollectionDecorator<E>

remove

public boolean remove(Object object)

Description copied from interface: MultiSet

Removes one occurrence of the given object from the MultiSet.

If the number of occurrences after this operations is reduced to zero, the object will be removed from the MultiSet.uniqueSet().

Specified by:

remove in interface Collection<E>

Specified by:

remove in interface MultiSet<E>

Overrides:

remove in class AbstractCollectionDecorator<E>

Parameters:

object - the object to remove

Returns:

true if this call changed the collection

removeAll

public boolean removeAll(Collection<?> coll)

Description copied from interface: MultiSet

Remove all occurrences of all elements from this MultiSet represented in the given collection.

Specified by:

removeAll in interface Collection<E>

Specified by:

removeAll in interface MultiSet<E>

Overrides:

removeAll in class AbstractCollectionDecorator<E>

Parameters:

coll - the collection of elements to remove

Returns:

true if this call changed the multiset

retainAll

public boolean retainAll(Collection<?> coll)

Description copied from interface: MultiSet

Remove any elements of this MultiSet that are not contained in the given collection.

Specified by:

retainAll in interface Collection<E>

Specified by:

retainAll in interface MultiSet<E>

Overrides:

retainAll in class AbstractCollectionDecorator<E>

Parameters:

coll - the collection of elements to retain

Returns:

true if this call changed the multiset

setCount

public int setCount(E object,
                    int count)

Description copied from interface: MultiSet

Sets the number of occurrences of the specified object in the MultiSet to the given count.

If the provided count is zero, the object will be removed from the MultiSet.uniqueSet().

Specified by:

setCount in interface MultiSet<E>

Overrides:

setCount in class AbstractMultiSetDecorator<E>

Parameters:

object - the object to update

count - the number of occurrences of the object

Returns:

the number of occurrences of the object before this operation, zero if the object was not contained in the multiset

add

public int add(E object,
               int count)

Description copied from interface: MultiSet

Adds a number of occurrences of the specified object to the MultiSet.

If the object is already in the MultiSet.uniqueSet() then increment its count as reported by MultiSet.getCount(Object). Otherwise add it to the MultiSet.uniqueSet() and report its count as occurrences.

Specified by:

add in interface MultiSet<E>

Overrides:

add in class AbstractMultiSetDecorator<E>

Parameters:

object - the object to add

count - the number of occurrences to add, may be zero, in which case no change is made to the multiset

Returns:

the number of occurrences of the object in the multiset before this operation; possibly zero

remove

public int remove(Object object,
                  int count)

Description copied from interface: MultiSet

Removes a number of occurrences of the specified object from the MultiSet.

If the number of occurrences to remove is greater than the actual number of occurrences in the multiset, the object will be removed from the multiset.

Specified by:

remove in interface MultiSet<E>

Overrides:

remove in class AbstractMultiSetDecorator<E>

Parameters:

object - the object to remove

count - the number of occurrences to remove, may be zero, in which case no change is made to the multiset

Returns:

the number of occurrences of the object in the multiset before the operation; possibly zero

uniqueSet

public Set<E> uniqueSet()

Description copied from interface: MultiSet

Returns a Set of unique elements in the MultiSet.

Uniqueness constraints are the same as those in Set.

The returned set is backed by this multiset, so any change to either is immediately reflected in the other. Only removal operations are supported, in which case all occurrences of the element are removed from the backing multiset.

Specified by:

uniqueSet in interface MultiSet<E>

Overrides:

uniqueSet in class AbstractMultiSetDecorator<E>

Returns:

the Set of unique MultiSet elements

entrySet

public Set<MultiSet.Entry<E>> entrySet()

Description copied from interface: MultiSet

Returns a Set of all entries contained in the MultiSet.

The returned set is backed by this multiset, so any change to either is immediately reflected in the other.

Specified by:

entrySet in interface MultiSet<E>

Overrides:

entrySet in class AbstractMultiSetDecorator<E>

Returns:

the Set of MultiSet entries