Module org.apache.jena.arq

Package org.apache.jena.sparql.engine.iterator

Class QueryIteratorBase

java.lang.Object

org.apache.jena.sparql.util.PrintSerializableBase

org.apache.jena.sparql.engine.iterator.QueryIteratorBase

All Implemented Interfaces:

Iterator<Binding>, org.apache.jena.atlas.io.Printable, org.apache.jena.atlas.iterator.IteratorCloseable<Binding>, org.apache.jena.atlas.lib.Closeable, QueryIterator, PrintSerializable

Direct Known Subclasses:

QueryIter, QueryIteratorResultSet, QueryIteratorWrapper

public abstract class QueryIteratorBase
extends PrintSerializableBase
implements QueryIterator

This class provides the general machinery for iterators. This includes

• autoclose when the iterator runs out
• async cancellation
• final hasNext() and next() to check for cancellation. Subclasses provide two operations: hasNextBinding(), moveToNextBinding()

Method Summary

Modifier and Type	Method	Description
final void	cancel()	Cancel this iterator : this is called, possibly asynchronously, to cancel an iterator.
void	close()
final boolean	hasNext()	final - subclasses implement hasNextBinding()
final Binding	next()	final - autoclose and registration relies on it - implement moveToNextBinding()
final Binding	nextBinding()	final - subclasses implement moveToNextBinding()
final void	remove()

Methods inherited from class org.apache.jena.sparql.util.PrintSerializableBase

output, toString, toString

Methods inherited from class java.lang.Object

equals, getClass, hashCode, notify, notifyAll, wait, wait, wait

Methods inherited from interface java.util.Iterator

forEachRemaining

Methods inherited from interface org.apache.jena.atlas.io.Printable

output

Methods inherited from interface org.apache.jena.sparql.util.PrintSerializable

output, toString

Methods inherited from interface org.apache.jena.sparql.engine.QueryIterator

isJoinIdentity

Method Details

hasNext

public final boolean hasNext()

final - subclasses implement hasNextBinding()

Specified by:

hasNext in interface Iterator<Binding>

next

public final Binding next()

final - autoclose and registration relies on it - implement moveToNextBinding()

Specified by:

next in interface Iterator<Binding>

nextBinding

public final Binding nextBinding()

final - subclasses implement moveToNextBinding()

Specified by:

nextBinding in interface QueryIterator

remove

public final void remove()

Specified by:

remove in interface Iterator<Binding>

close

public void close()

Specified by:

close in interface org.apache.jena.atlas.lib.Closeable

cancel

public final void cancel()

Cancel this iterator : this is called, possibly asynchronously, to cancel an iterator.

Specified by:

cancel in interface QueryIterator