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

Class LeftJoinIterator

java.lang.Object

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

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

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

All Implemented Interfaces:

AutoCloseable, CloseableIteration<BindingSet,QueryEvaluationException>, Iteration<BindingSet,QueryEvaluationException>

Direct Known Subclasses:

BadlyDesignedLeftJoinIterator

public class LeftJoinIterator
extends LookAheadIteration<BindingSet,QueryEvaluationException>

Constructor Summary

Constructors

Constructor	Description
LeftJoinIterator(EvaluationStrategy strategy, LeftJoin join, BindingSet bindings, QueryEvaluationContext context)
LeftJoinIterator(QueryEvaluationStep left, QueryEvaluationStep right, QueryValueEvaluationStep joinCondition, BindingSet bindings, Set<String> scopeBindingNamse)

Method Summary

Modifier and Type	Method	Description
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 org.eclipse.rdf4j.common.iteration.LookAheadIteration

hasNext, next, remove

Methods inherited from class org.eclipse.rdf4j.common.iteration.AbstractCloseableIteration

close, isClosed

Methods inherited from class java.lang.Object

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

Methods inherited from interface org.eclipse.rdf4j.common.iteration.Iteration

stream

Constructor Details

LeftJoinIterator

public LeftJoinIterator(EvaluationStrategy strategy,
 LeftJoin join,
 BindingSet bindings,
 QueryEvaluationContext context)
                 throws QueryEvaluationException

Throws:

QueryEvaluationException

LeftJoinIterator

public LeftJoinIterator(QueryEvaluationStep left,
 QueryEvaluationStep right,
 QueryValueEvaluationStep joinCondition,
 BindingSet bindings,
 Set<String> scopeBindingNamse)
                 throws QueryEvaluationException

Throws:

QueryEvaluationException

Method Details

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,QueryEvaluationException>

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.

Overrides:

handleClose in class LookAheadIteration<BindingSet,QueryEvaluationException>

Throws:

QueryEvaluationException