org.openrdf.query.algebra.evaluation.iterator
Class LeftJoinIterator

java.lang.Object
  info.aduna.iteration.CloseableIterationBase<E,X>
      info.aduna.iteration.LookAheadIteration<BindingSet,QueryEvaluationException>
          org.openrdf.query.algebra.evaluation.iterator.LeftJoinIterator

All Implemented Interfaces:

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

Direct Known Subclasses:

BadlyDesignedLeftJoinIterator

public class LeftJoinIterator
extends LookAheadIteration<BindingSet,QueryEvaluationException>

Constructor Summary

LeftJoinIterator(EvaluationStrategy strategy, LeftJoin join, BindingSet bindings)

Method Summary

protected BindingSet	getNextElement() Gets the next element.
protected void	handleClose() Called by CloseableIterationBase.close() when it is called for the first time.

Methods inherited from class info.aduna.iteration.LookAheadIteration

hasNext, next, remove

Methods inherited from class info.aduna.iteration.CloseableIterationBase

close, isClosed

Methods inherited from class java.lang.Object

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

Constructor Detail

LeftJoinIterator

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

Throws:

QueryEvaluationException

Method Detail

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: CloseableIterationBase

Called by CloseableIterationBase.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