Package org.apache.cayenne.util.commons
Class CompositeCollection<E>
- java.lang.Object
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- org.apache.cayenne.util.commons.CompositeCollection<E>
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- All Implemented Interfaces:
Iterable<E>,Collection<E>
public class CompositeCollection<E> extends Object implements Collection<E>
Decorates a collection of other collections to provide a single unified view.Changes made to this collection will actually be made on the decorated collection. Add and remove operations require the use of a pluggable strategy. If no strategy is provided then add and remove are unsupported.
- Since:
- 4.1 NOTE: this is a simplified and type-safe version of CompositeCollection found in commons-collections v3.2.1
- Author:
- Brian McCallister, Stephen Colebourne, Phil Steitz
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Field Summary
Fields Modifier and Type Field Description protected ArrayList<Collection<E>>allCollections in the composite
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Constructor Summary
Constructors Constructor Description CompositeCollection()Create an empty CompositeCollection.
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Method Summary
All Methods Instance Methods Concrete Methods Modifier and Type Method Description booleanadd(Object obj)Adds an object to the collection, throwing UnsupportedOperationException unless a CollectionMutator strategy is specified.booleanaddAll(Collection<? extends E> coll)Adds a collection of elements to this collection, throwing UnsupportedOperationException unless a CollectionMutator strategy is specified.voidaddComposited(Collection<E> c)Add an additional collection to this composite.voidclear()Removes all of the elements from this collection .booleancontains(Object obj)Checks whether this composite collection contains the object.booleancontainsAll(Collection<?> coll)Checks whether this composite contains all the elements in the specified collection.Collection<Collection<E>>getCollections()Gets the collections being decorated.booleanisEmpty()Checks whether this composite collection is empty.Iterator<E>iterator()Gets an iterator over all the collections in this composite.booleanremove(Object obj)Removes an object from the collection, throwing UnsupportedOperationException unless a CollectionMutator strategy is specified.booleanremoveAll(Collection<?> coll)Removes the elements in the specified collection from this composite collection.voidremoveComposited(Collection<E> coll)Removes a collection from the those being decorated in this composite.booleanretainAll(Collection<?> coll)Retains all the elements in the specified collection in this composite collection, removing all others.intsize()Gets the size of this composite collection.Object[]toArray()Returns an array containing all of the elements in this composite.<T> T[]toArray(T[] array)Returns an object array, populating the supplied array if possible.-
Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
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Methods inherited from interface java.util.Collection
equals, hashCode, parallelStream, removeIf, spliterator, stream, toArray
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Field Detail
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all
protected ArrayList<Collection<E>> all
Collections in the composite
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Method Detail
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size
public int size()
Gets the size of this composite collection.This implementation calls
size()on each collection.- Specified by:
sizein interfaceCollection<E>- Returns:
- total number of elements in all contained containers
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isEmpty
public boolean isEmpty()
Checks whether this composite collection is empty.This implementation calls
isEmpty()on each collection.- Specified by:
isEmptyin interfaceCollection<E>- Returns:
- true if all of the contained collections are empty
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contains
public boolean contains(Object obj)
Checks whether this composite collection contains the object.This implementation calls
contains()on each collection.- Specified by:
containsin interfaceCollection<E>- Parameters:
obj- the object to search for- Returns:
- true if obj is contained in any of the contained collections
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iterator
public Iterator<E> iterator()
Gets an iterator over all the collections in this composite.This implementation uses an
IteratorChain.- Specified by:
iteratorin interfaceCollection<E>- Specified by:
iteratorin interfaceIterable<E>- Returns:
- an
IteratorChaininstance which supportsremove(). Iteration occurs over contained collections in the order they were added, but this behavior should not be relied upon. - See Also:
IteratorChain
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toArray
public Object[] toArray()
Returns an array containing all of the elements in this composite.- Specified by:
toArrayin interfaceCollection<E>- Returns:
- an object array of all the elements in the collection
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toArray
public <T> T[] toArray(T[] array)
Returns an object array, populating the supplied array if possible. SeeCollectioninterface for full details.- Specified by:
toArrayin interfaceCollection<E>- Parameters:
array- the array to use, populating if possible- Returns:
- an array of all the elements in the collection
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add
public boolean add(Object obj)
Adds an object to the collection, throwing UnsupportedOperationException unless a CollectionMutator strategy is specified.- Specified by:
addin interfaceCollection<E>- Parameters:
obj- the object to add- Returns:
- true if the collection was modified
- Throws:
UnsupportedOperationException- if CollectionMutator hasn't been setUnsupportedOperationException- if add is unsupportedClassCastException- if the object cannot be added due to its typeNullPointerException- if the object cannot be added because its nullIllegalArgumentException- if the object cannot be added
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remove
public boolean remove(Object obj)
Removes an object from the collection, throwing UnsupportedOperationException unless a CollectionMutator strategy is specified.- Specified by:
removein interfaceCollection<E>- Parameters:
obj- the object being removed- Returns:
- true if the collection is changed
- Throws:
UnsupportedOperationException- if removed is unsupportedClassCastException- if the object cannot be removed due to its typeNullPointerException- if the object cannot be removed because its nullIllegalArgumentException- if the object cannot be removed
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containsAll
public boolean containsAll(Collection<?> coll)
Checks whether this composite contains all the elements in the specified collection.This implementation calls
contains()for each element in the specified collection.- Specified by:
containsAllin interfaceCollection<E>- Parameters:
coll- the collection to check for- Returns:
- true if all elements contained
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addAll
public boolean addAll(Collection<? extends E> coll)
Adds a collection of elements to this collection, throwing UnsupportedOperationException unless a CollectionMutator strategy is specified.- Specified by:
addAllin interfaceCollection<E>- Parameters:
coll- the collection to add- Returns:
- true if the collection was modified
- Throws:
UnsupportedOperationException- if CollectionMutator hasn't been setUnsupportedOperationException- if add is unsupportedClassCastException- if the object cannot be added due to its typeNullPointerException- if the object cannot be added because its nullIllegalArgumentException- if the object cannot be added
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removeAll
public boolean removeAll(Collection<?> coll)
Removes the elements in the specified collection from this composite collection.This implementation calls
removeAllon each collection.- Specified by:
removeAllin interfaceCollection<E>- Parameters:
coll- the collection to remove- Returns:
- true if the collection was modified
- Throws:
UnsupportedOperationException- if removeAll is unsupported
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retainAll
public boolean retainAll(Collection<?> coll)
Retains all the elements in the specified collection in this composite collection, removing all others.This implementation calls
retainAll()on each collection.- Specified by:
retainAllin interfaceCollection<E>- Parameters:
coll- the collection to remove- Returns:
- true if the collection was modified
- Throws:
UnsupportedOperationException- if retainAll is unsupported
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clear
public void clear()
Removes all of the elements from this collection .This implementation calls
clear()on each collection.- Specified by:
clearin interfaceCollection<E>- Throws:
UnsupportedOperationException- if clear is unsupported
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addComposited
public void addComposited(Collection<E> c)
Add an additional collection to this composite.- Parameters:
c- the collection to add
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removeComposited
public void removeComposited(Collection<E> coll)
Removes a collection from the those being decorated in this composite.- Parameters:
coll- collection to be removed
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getCollections
public Collection<Collection<E>> getCollections()
Gets the collections being decorated.- Returns:
- Unmodifiable collection of all collections in this composite.
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