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

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

All Implemented Interfaces:

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

public class OrderIterator
extends DelayedIteration<BindingSet,QueryEvaluationException>

Sorts the input and optionally applies limit and distinct.

Author:

James Leigh, Arjohn Kampman

Constructor Summary

OrderIterator(CloseableIteration<BindingSet,QueryEvaluationException> iter, Comparator<BindingSet> comparator)

OrderIterator(CloseableIteration<BindingSet,QueryEvaluationException> iter, Comparator<BindingSet> comparator, long limit, boolean distinct)

Method Summary

protected Iteration<BindingSet,QueryEvaluationException>	createIteration() Creates the iteration that should be iterated over.
protected void	handleClose() Closes this iteration as well as the underlying iteration if it has already been created and happens to be a CloseableIteration.
void	remove() Calls the remove method of the underlying iteration.

Methods inherited from class info.aduna.iteration.DelayedIteration

hasNext, next

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

OrderIterator

public OrderIterator(CloseableIteration<BindingSet,QueryEvaluationException> iter,
                     Comparator<BindingSet> comparator)

OrderIterator

public OrderIterator(CloseableIteration<BindingSet,QueryEvaluationException> iter,
                     Comparator<BindingSet> comparator,
                     long limit,
                     boolean distinct)

Method Detail

createIteration

protected Iteration<BindingSet,QueryEvaluationException> 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,QueryEvaluationException>

Throws:

QueryEvaluationException

remove

public void remove()
            throws QueryEvaluationException

Description copied from class: DelayedIteration

Calls the remove method of the underlying iteration.

Specified by:

remove in interface Iteration<BindingSet,QueryEvaluationException>

Overrides:

remove in class DelayedIteration<BindingSet,QueryEvaluationException>

Throws:

QueryEvaluationException

handleClose

protected void handleClose()
                    throws QueryEvaluationException

Description copied from class: DelayedIteration

Closes this iteration as well as the underlying iteration if it has already been created and happens to be a CloseableIteration.

Overrides:

handleClose in class DelayedIteration<BindingSet,QueryEvaluationException>

Throws:

QueryEvaluationException