Class QueryEvaluationStep.DelayedEvaluationIteration

java.lang.Object

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

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

org.eclipse.rdf4j.query.algebra.evaluation.QueryEvaluationStep.DelayedEvaluationIteration

All Implemented Interfaces:

AutoCloseable, Iterator<BindingSet>, CloseableIteration<BindingSet>

Enclosing interface:

QueryEvaluationStep

public static class QueryEvaluationStep.DelayedEvaluationIteration
extends DelayedIteration<BindingSet>

Utility class that removes code duplication and makes a precompiled QueryEvaluationStep available as an iteration that may be created and used later.

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
DelayedEvaluationIteration(QueryEvaluationStep arg, BindingSet bs)

Method Summary

Modifier and Type	Method	Description
protected CloseableIteration<? extends BindingSet>	createIteration()	Creates the iteration that should be iterated over.

Methods inherited from class DelayedIteration

handleClose, hasNext, next, remove

Modifier and Type	Method	Description
protected void	handleClose()	Closes this iteration as well as the underlying iteration if it has already been created and happens to be a CloseableIteration.
boolean	hasNext()	Calls the hasNext method of the underlying iteration.
BindingSet	next()	Calls the next method of the underlying iteration.
void	remove()	Calls the remove method of the underlying iteration.

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

DelayedEvaluationIteration

public DelayedEvaluationIteration(QueryEvaluationStep arg,
 BindingSet bs)

Method Details

createIteration

protected CloseableIteration<? extends BindingSet> createIteration()
                                                            throws QueryEvaluationException

Description copied from class: DelayedIteration

Creates the iteration that should be iterated over. This method is called only once, when the iteration is first needed.

Specified by:

createIteration in class DelayedIteration<BindingSet>

Throws:

QueryEvaluationException