org.eclipse.rdf4j.common.iteration

Class IntersectIteration<E,X extends Exception>

java.lang.Object

org.eclipse.rdf4j.common.iteration.AbstractCloseableIteration<E,X>

org.eclipse.rdf4j.common.iteration.IterationWrapper<E,X>

org.eclipse.rdf4j.common.iteration.FilterIteration<E,X>

org.eclipse.rdf4j.common.iteration.IntersectIteration<E,X>

All Implemented Interfaces:

AutoCloseable, CloseableIteration<E,X>, Iteration<E,X>

Direct Known Subclasses:

LimitedSizeIntersectIteration

public class IntersectIteration<E,X extends Exception>
extends FilterIteration<E,X>

An Iteration that returns the intersection of the results of two Iterations. Optionally, the Iteration can be configured to filter duplicates from the returned elements.

Note that duplicates can also be filtered by wrapping this Iteration in a DistinctIteration, but that has a bit more overhead as it adds a second hash table lookup.

Field Summary

Fields

Modifier and Type	Field and Description
protected Iteration<? extends E,? extends X>	arg2

Fields inherited from class org.eclipse.rdf4j.common.iteration.IterationWrapper

wrappedIter

Constructor Summary

Constructors

Constructor and Description
IntersectIteration(Iteration<? extends E,? extends X> arg1, Iteration<? extends E,? extends X> arg2) Creates a new IntersectIteration that returns the intersection of the results of two Iterations.
IntersectIteration(Iteration<? extends E,? extends X> arg1, Iteration<? extends E,? extends X> arg2, boolean distinct) Creates a new IntersectIteration that returns the intersection of the results of two Iterations.

Method Summary

Modifier and Type	Method and Description
protected boolean	accept(E object) Returns true if the object is in the set of elements of the second argument.
Set<E>	addSecondSet(Iteration<? extends E,? extends X> arg2, Set<E> set)
protected long	clearIncludeSet()
protected void	handleClose() Closes this Iteration and also closes the wrapped Iteration if it is a CloseableIteration.
protected boolean	inIncludeSet(E object)
protected Set<E>	makeSet()
protected boolean	removeFromIncludeSet(E object)

Methods inherited from class org.eclipse.rdf4j.common.iteration.FilterIteration

hasNext, next

Methods inherited from class org.eclipse.rdf4j.common.iteration.IterationWrapper

remove

Methods inherited from class org.eclipse.rdf4j.common.iteration.AbstractCloseableIteration

close, isClosed

Methods inherited from class java.lang.Object

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

Field Detail

arg2

protected final Iteration<? extends E,? extends X extends Exception> arg2

Constructor Detail

IntersectIteration

public IntersectIteration(Iteration<? extends E,? extends X> arg1,
                          Iteration<? extends E,? extends X> arg2)

Creates a new IntersectIteration that returns the intersection of the results of two Iterations. By default, duplicates are not filtered from the results.

Parameters:

arg1 - An Iteration containing the first set of elements.

arg2 - An Iteration containing the second set of elements.

IntersectIteration

public IntersectIteration(Iteration<? extends E,? extends X> arg1,
                          Iteration<? extends E,? extends X> arg2,
                          boolean distinct)

Creates a new IntersectIteration that returns the intersection of the results of two Iterations.

Parameters:

arg1 - An Iteration containing the first set of elements.

arg2 - An Iteration containing the second set of elements.

distinct - Flag indicating whether duplicate elements should be filtered from the result.

Method Detail

accept

protected boolean accept(E object)
                  throws X extends Exception

Returns true if the object is in the set of elements of the second argument.

Specified by:

accept in class FilterIteration<E,X extends Exception>

Parameters:

object - The object to be tested.

Returns:

true if the object should be returned, false otherwise.

Throws:

X

X extends Exception

addSecondSet

public Set<E> addSecondSet(Iteration<? extends E,? extends X> arg2,
                           Set<E> set)
                    throws X extends Exception

Throws:

X extends Exception

removeFromIncludeSet

protected boolean removeFromIncludeSet(E object)

inIncludeSet

protected boolean inIncludeSet(E object)

makeSet

protected Set<E> makeSet()

handleClose

protected void handleClose()
                    throws X extends Exception

Description copied from class: IterationWrapper

Closes this Iteration and also closes the wrapped Iteration if it is a CloseableIteration.

Overrides:

handleClose in class FilterIteration<E,X extends Exception>

Throws:

X

X extends Exception

clearIncludeSet

protected long clearIncludeSet()