Package org.apache.cayenne.util.commons
Class CompositeCollection<E>
java.lang.Object
org.apache.cayenne.util.commons.CompositeCollection<E>
- 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 -
Constructor Summary
Constructors Constructor Description CompositeCollection()Create an empty CompositeCollection. -
Method Summary
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, waitMethods inherited from interface java.util.Collection
equals, hashCode, parallelStream, removeIf, spliterator, stream, toArray
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Field Details
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all
Collections in the composite
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Constructor Details
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CompositeCollection
public CompositeCollection()Create an empty CompositeCollection.
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Method Details
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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
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
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
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
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
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
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
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
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
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
Add an additional collection to this composite.- Parameters:
c- the collection to add
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removeComposited
Removes a collection from the those being decorated in this composite.- Parameters:
coll- collection to be removed
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getCollections
Gets the collections being decorated.- Returns:
- Unmodifiable collection of all collections in this composite.
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