Class LeftJoinIterator

java.lang.Object

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

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

org.eclipse.rdf4j.query.algebra.evaluation.iterator.LeftJoinIterator

All Implemented Interfaces:

AutoCloseable, Iterator<BindingSet>, CloseableIteration<BindingSet>

public class LeftJoinIterator
extends LookAheadIteration<BindingSet>

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
LeftJoinIterator(CloseableIteration<BindingSet> leftIter, QueryEvaluationStep rightEvaluationStep)
LeftJoinIterator(EvaluationStrategy strategy, LeftJoin join, BindingSet bindings, QueryEvaluationStep rightEvaluationStep)
LeftJoinIterator(QueryEvaluationStep left, BindingSet bindings, QueryEvaluationStep rightEvaluationStep)

Method Summary

Modifier and Type	Method	Description
static CloseableIteration<BindingSet>	getInstance(QueryEvaluationStep left, BindingSet bindings, QueryEvaluationStep rightEvaluationStep)
protected BindingSet	getNextElement()	Gets the next element.
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 BindingSet	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<BindingSet>	stream()	Convert the results to a Java 8 Stream.

Methods inherited from interface Iterator

forEachRemaining

Constructor Details

LeftJoinIterator

public LeftJoinIterator(EvaluationStrategy strategy,
 LeftJoin join,
 BindingSet bindings,
 QueryEvaluationStep rightEvaluationStep)
                 throws QueryEvaluationException

Throws:

QueryEvaluationException

LeftJoinIterator

public LeftJoinIterator(QueryEvaluationStep left,
 BindingSet bindings,
 QueryEvaluationStep rightEvaluationStep)
                 throws QueryEvaluationException

Throws:

QueryEvaluationException

LeftJoinIterator

public LeftJoinIterator(CloseableIteration<BindingSet> leftIter,
 QueryEvaluationStep rightEvaluationStep)

Method Details

getInstance

public static CloseableIteration<BindingSet> getInstance(QueryEvaluationStep left,
 BindingSet bindings,
 QueryEvaluationStep rightEvaluationStep)

getNextElement

protected BindingSet getNextElement()
                             throws QueryEvaluationException

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<BindingSet>

Returns:

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

Throws:

QueryEvaluationException

handleClose

protected void handleClose()
                    throws QueryEvaluationException

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<BindingSet>

Throws:

QueryEvaluationException