org.openrdf.sail.federation.evaluation
Class AlternativeCursor<E>

java.lang.Object
  info.aduna.iteration.CloseableIterationBase<E,X>
      info.aduna.iteration.LookAheadIteration<E,QueryEvaluationException>
          org.openrdf.sail.federation.evaluation.AlternativeCursor<E>

All Implemented Interfaces:

CloseableIteration<E,QueryEvaluationException>, Iteration<E,QueryEvaluationException>

public class AlternativeCursor<E>
extends LookAheadIteration<E,QueryEvaluationException>

If the primary cursor is empty, use the alternative cursor.

Author:

James Leigh

Constructor Summary

AlternativeCursor(CloseableIteration<? extends E,QueryEvaluationException> primary, CloseableIteration<? extends E,QueryEvaluationException> alternative)

Method Summary

E	getNextElement()
void	handleClose()
String	toString()

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, wait, wait, wait

Constructor Detail

AlternativeCursor

public AlternativeCursor(CloseableIteration<? extends E,QueryEvaluationException> primary,
                         CloseableIteration<? extends E,QueryEvaluationException> alternative)

Method Detail

handleClose

public void handleClose()
                 throws QueryEvaluationException

Overrides:

handleClose in class LookAheadIteration<E,QueryEvaluationException>

Throws:

QueryEvaluationException

getNextElement

public E getNextElement()
                 throws QueryEvaluationException

Specified by:

getNextElement in class LookAheadIteration<E,QueryEvaluationException>

Throws:

QueryEvaluationException

toString

public String toString()

Overrides:

toString in class Object