Class UnionIteration<E>

java.lang.Object

org.eclipse.rdf4j.common.iteration.AbstractCloseableIteration<E>

org.eclipse.rdf4j.common.iteration.LookAheadIteration<E>

org.eclipse.rdf4j.common.iteration.UnionIteration<E>

All Implemented Interfaces:

AutoCloseable, Iterator<E>, CloseableIteration<E>, IndexReportingIterator

public class UnionIteration<E>
extends LookAheadIteration<E>
implements IndexReportingIterator

An Iteration that returns the bag union of the results of a number of Iterations. 'Bag union' means that the UnionIteration does not filter duplicate objects.

Field Summary

Fields inherited from interface CloseableIteration

EMPTY_STATEMENT_ITERATION

Modifier and Type	Field	Description
static final EmptyIteration<Statement>	EMPTY_STATEMENT_ITERATION

Constructor Summary

Constructors

Constructor	Description
UnionIteration(Iterable<? extends CloseableIteration<? extends E>> args)	Creates a new UnionIteration that returns the bag union of the results of a number of Iterations.
UnionIteration(CloseableIteration<? extends E>... args)	Creates a new UnionIteration that returns the bag union of the results of a number of Iterations.

Method Summary

Modifier and Type	Method	Description
String	getIndexName()
protected E	getNextElement()	Gets the next element.
long	getSourceRowsFilteredActual()
long	getSourceRowsMatchedActual()
long	getSourceRowsScannedActual()
protected void	handleClose()	Called by AbstractCloseableIteration.close() when it is called for the first time.

Methods inherited from class LookAheadIteration

hasNext, next, remove

Modifier and Type	Method	Description
final boolean	hasNext()
final E	next()
void	remove()	Throws an UnsupportedOperationException.

Methods inherited from class AbstractCloseableIteration

close, isClosed

Modifier and Type	Method	Description
final void	close()	Calls AbstractCloseableIteration.handleClose() upon first call and makes sure the resource closures are only executed once.
final boolean	isClosed()	Checks whether this CloseableIteration has been closed.

Methods inherited from class Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Methods inherited from interface CloseableIteration

stream

Modifier and Type	Method	Description
default Stream<E>	stream()	Convert the results to a Java 8 Stream.

Methods inherited from interface Iterator

forEachRemaining

Constructor Details

UnionIteration

@SafeVarargs
public UnionIteration(CloseableIteration<? extends E>... args)

Creates a new UnionIteration that returns the bag union of the results of a number of Iterations.

Parameters:

args - The Iterations containing the elements to iterate over.

UnionIteration

public UnionIteration(Iterable<? extends CloseableIteration<? extends E>> args)

Creates a new UnionIteration that returns the bag union of the results of a number of Iterations.

Parameters:

args - The Iterations containing the elements to iterate over.

Method Details

getNextElement

protected E getNextElement()

Description copied from class: LookAheadIteration

Gets the next element. Subclasses should implement this method so that it returns the next element.

Specified by:

getNextElement in class LookAheadIteration<E>

Returns:

The next element, or null if no more elements are available.

handleClose

protected void handleClose()

Description copied from class: AbstractCloseableIteration

Called by AbstractCloseableIteration.close() when it is called for the first time. This method is only called once on each iteration. By default, this method does nothing.

Specified by:

handleClose in class AbstractCloseableIteration<E>

getIndexName

public String getIndexName()

Specified by:

getIndexName in interface IndexReportingIterator

getSourceRowsScannedActual

public long getSourceRowsScannedActual()

Specified by:

getSourceRowsScannedActual in interface IndexReportingIterator

getSourceRowsMatchedActual

public long getSourceRowsMatchedActual()

Specified by:

getSourceRowsMatchedActual in interface IndexReportingIterator

getSourceRowsFilteredActual

public long getSourceRowsFilteredActual()

Specified by:

getSourceRowsFilteredActual in interface IndexReportingIterator