Package org.eclipse.rdf4j.federated.evaluation.iterator

Class ConsumingIteration

java.lang.Object

org.eclipse.rdf4j.federated.evaluation.iterator.ConsumingIteration

All Implemented Interfaces:

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

public class ConsumingIteration
extends Object
implements CloseableIteration<BindingSet,QueryEvaluationException>

A specialized CloseableIteration that consumes part (or the entire input iteration if it fits into the buffer) and keeps data for further processing in memory. If the buffer is full, the remaining items will be read from the iteration lazily. This implementation can be used to avoid blocking behavior in HTTP connection streams, i.e. to process results in memory and close the underlying HTTP stream.

Author:

Andreas Schwarte

Constructor Summary

Constructors

Constructor	Description
ConsumingIteration(CloseableIteration<BindingSet,QueryEvaluationException> iter, int max)

Method Summary

Modifier and Type	Method	Description
void	close()	Closes this iteration, freeing any resources that it is holding.
boolean	hasNext()	Returns true if the iteration has more elements.
BindingSet	next()	Returns the next element in the iteration.
void	remove()	Removes from the underlying collection the last element returned by the iteration (optional operation).

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.CloseableIteration

stream

Constructor Details

ConsumingIteration

public ConsumingIteration(CloseableIteration<BindingSet,QueryEvaluationException> iter,
 int max)
                   throws QueryEvaluationException

Parameters:

iter - iteration to be consumed

max - the number of results to be consumed.

Throws:

QueryEvaluationException

Method Details

hasNext

public boolean hasNext()
                throws QueryEvaluationException

Description copied from interface: Iteration

Returns true if the iteration has more elements. (In other words, returns true if Iteration.next() would return an element rather than throwing a NoSuchElementException.)

Specified by:

hasNext in interface Iteration<BindingSet,QueryEvaluationException>

Returns:

true if the iteration has more elements.

Throws:

QueryEvaluationException

next

public BindingSet next()
                throws QueryEvaluationException

Description copied from interface: Iteration

Returns the next element in the iteration.

Specified by:

next in interface Iteration<BindingSet,QueryEvaluationException>

Returns:

the next element in the iteration.

Throws:

QueryEvaluationException

remove

public void remove()
            throws QueryEvaluationException

Description copied from interface: Iteration

Removes from the underlying collection the last element returned by the iteration (optional operation). This method can be called only once per call to next.

Specified by:

remove in interface Iteration<BindingSet,QueryEvaluationException>

Throws:

QueryEvaluationException

close

public void close()
           throws QueryEvaluationException

Description copied from interface: CloseableIteration

Closes this iteration, freeing any resources that it is holding. If the iteration has already been closed then invoking this method has no effect.

Specified by:

close in interface AutoCloseable

Specified by:

close in interface CloseableIteration<BindingSet,QueryEvaluationException>

Throws:

QueryEvaluationException