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)	Always throws UnsupportedOperationException.
int	add(E object, int count)	Always throws UnsupportedOperationException.
boolean	addAll(Collection<? extends E> coll)	Always throws UnsupportedOperationException.
void	clear()	Always throws UnsupportedOperationException.
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)	Always throws UnsupportedOperationException.
int	remove(Object object, int count)	Always throws UnsupportedOperationException.
boolean	removeAll(Collection<?> coll)	Always throws UnsupportedOperationException.
boolean	removeIf(Predicate<? super E> filter)	Always throws UnsupportedOperationException.
boolean	retainAll(Collection<?> coll)	Always throws UnsupportedOperationException.
int	setCount(E object, int count)	Always throws UnsupportedOperationException.
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, spliterator, stream, toArray, toArray

Methods inherited from interface java.lang.Iterable

forEach

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

containsAll, size

Method Details

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

add

public boolean add(E object)

Always throws UnsupportedOperationException.

Specified by:

add in interface Collection<E>

Specified by:

add in interface MultiSet<E>

Overrides:

add in class AbstractCollectionDecorator<E>

Parameters:

object - Ignored.

Returns:

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

Throws:

UnsupportedOperationException - Always thrown.

add

public int add(E object,
 int count)

Always throws UnsupportedOperationException.

Specified by:

add in interface MultiSet<E>

Overrides:

add in class AbstractMultiSetDecorator<E>

Parameters:

object - Ignored.

count - Ignored.

Returns:

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

Throws:

UnsupportedOperationException - Always thrown.

addAll

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

Always throws UnsupportedOperationException.

Specified by:

addAll in interface Collection<E>

Overrides:

addAll in class AbstractCollectionDecorator<E>

Parameters:

coll - Ignored.

Throws:

UnsupportedOperationException - Always thrown.

clear

public void clear()

Always throws UnsupportedOperationException.

Specified by:

clear in interface Collection<E>

Overrides:

clear in class AbstractCollectionDecorator<E>

Throws:

UnsupportedOperationException - Always thrown.

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.

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.

remove

public boolean remove(Object object)

Always throws UnsupportedOperationException.

Specified by:

remove in interface Collection<E>

Specified by:

remove in interface MultiSet<E>

Overrides:

remove in class AbstractCollectionDecorator<E>

Parameters:

object - Ignored.

Returns:

true if this call changed the collection.

Throws:

UnsupportedOperationException - Always thrown.

remove

public int remove(Object object,
 int count)

Always throws UnsupportedOperationException.

Specified by:

remove in interface MultiSet<E>

Overrides:

remove in class AbstractMultiSetDecorator<E>

Parameters:

object - Ignored.

count - Ignored.

Returns:

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

Throws:

UnsupportedOperationException - Always thrown.

removeAll

public boolean removeAll(Collection<?> coll)

Always throws UnsupportedOperationException.

Specified by:

removeAll in interface Collection<E>

Specified by:

removeAll in interface MultiSet<E>

Overrides:

removeAll in class AbstractCollectionDecorator<E>

Parameters:

coll - Ignored.

Returns:

true if this call changed the multiset.

Throws:

UnsupportedOperationException - Always thrown.

removeIf

public boolean removeIf(Predicate<? super E> filter)

Always throws UnsupportedOperationException.

Specified by:

removeIf in interface Collection<E>

Overrides:

removeIf in class AbstractCollectionDecorator<E>

Parameters:

filter - Ignored.

Throws:

UnsupportedOperationException - Always thrown.

Since:

4.4

retainAll

public boolean retainAll(Collection<?> coll)

Always throws UnsupportedOperationException.

Specified by:

retainAll in interface Collection<E>

Specified by:

retainAll in interface MultiSet<E>

Overrides:

retainAll in class AbstractCollectionDecorator<E>

Parameters:

coll - Ignored.

Returns:

true if this call changed the multiset.

Throws:

UnsupportedOperationException - Always thrown.

setCount

public int setCount(E object,
 int count)

Always throws UnsupportedOperationException.

Specified by:

setCount in interface MultiSet<E>

Overrides:

setCount in class AbstractMultiSetDecorator<E>

Parameters:

object - Ignored.

count - Ignored.

Returns:

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

Throws:

UnsupportedOperationException - Always thrown.

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.