Class BackgroundTupleResult

java.lang.Object

org.eclipse.rdf4j.common.iteration.AbstractCloseableIteration<BindingSet>

org.eclipse.rdf4j.common.iteration.IterationWrapper<BindingSet>

org.eclipse.rdf4j.query.impl.IteratingTupleQueryResult

org.eclipse.rdf4j.query.resultio.helpers.BackgroundTupleResult

All Implemented Interfaces:

AutoCloseable, Iterable<BindingSet>, Runnable, Iterator<BindingSet>, CloseableIteration<BindingSet>, QueryResult<BindingSet>, QueryResultHandler, TupleQueryResult, TupleQueryResultHandler

public class BackgroundTupleResult
extends IteratingTupleQueryResult
implements Runnable, TupleQueryResultHandler

Provides concurrent access to tuple results as they are being parsed.

Author:

James Leigh

Field Summary

Fields inherited from class IterationWrapper

wrappedIter

Modifier and Type	Field	Description
protected final CloseableIteration<? extends BindingSet>	wrappedIter	Deprecated. This will be changed to private, possibly with an accessor in future.

Fields inherited from interface CloseableIteration

EMPTY_STATEMENT_ITERATION

Modifier and Type	Field	Description
static final EmptyIteration<Statement>	EMPTY_STATEMENT_ITERATION

Constructor Summary

Constructors

Constructor	Description
BackgroundTupleResult(QueueCursor<BindingSet> queue, TupleQueryResultParser parser, InputStream in)
BackgroundTupleResult(TupleQueryResultParser parser, InputStream in)

Method Summary

Modifier and Type	Method	Description
void	endQueryResult()	Indicates the end of a sequence of solutions.
List<String>	getBindingNames()	Gets the names of the bindings, in order of projection.
void	handleBoolean(boolean value)	Handles the specified boolean value.
protected void	handleClose()	Closes this Iteration and also closes the wrapped Iteration if it is a CloseableIteration.
void	handleLinks(List<String> linkUrls)	Handles the links elements which are present in SPARQL Results JSON and SPARQL Results XML documents in the header.
void	handleSolution(BindingSet bindingSet)	Handles a solution.
void	run()
void	startQueryResult(List<String> bindingNames)	Indicates the start of a sequence of Solutions.

Methods inherited from class IterationWrapper

hasNext, next, remove

Modifier and Type	Method	Description
boolean	hasNext()	Deprecated. Checks whether the wrapped Iteration contains more elements, closing this Iteration when this is not the case.
BindingSet	next()	Deprecated. Returns the next element from the wrapped Iteration.
void	remove()	Deprecated. Removes the last element that has been returned from the wrapped Iteration.

Methods inherited from class AbstractCloseableIteration

close, isClosed

Modifier and Type	Method	Description
final void	close()	Calls AbstractCloseableIteration.handleClose() upon first call and makes sure the resource closures are only executed once.
final boolean	isClosed()	Checks whether this CloseableIteration has been closed.

Methods inherited from class Object

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

Methods inherited from interface Iterable

forEach, spliterator

Methods inherited from interface Iterator

forEachRemaining

Methods inherited from interface QueryResult

hasNext, iterator, next, stream

Modifier and Type	Method	Description
boolean	hasNext()	Returns true if the query result has more elements.
default Iterator<BindingSet>	iterator()
BindingSet	next()	Returns the next element in the query result.
default Stream<BindingSet>	stream()	Convert the result elements to a Java Stream.

Constructor Details

BackgroundTupleResult

public BackgroundTupleResult(TupleQueryResultParser parser,
 InputStream in)

BackgroundTupleResult

public BackgroundTupleResult(QueueCursor<BindingSet> queue,
 TupleQueryResultParser parser,
 InputStream in)

Method Details

handleClose

protected void handleClose()
                    throws QueryEvaluationException

Description copied from class: IterationWrapper

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

Overrides:

handleClose in class IterationWrapper<BindingSet>

Throws:

QueryEvaluationException

getBindingNames

public List<String> getBindingNames()

Description copied from interface: TupleQueryResult

Gets the names of the bindings, in order of projection.

Specified by:

getBindingNames in interface TupleQueryResult

Overrides:

getBindingNames in class IteratingTupleQueryResult

Returns:

The binding names, in order of projection.

run

public void run()

Specified by:

run in interface Runnable

startQueryResult

public void startQueryResult(List<String> bindingNames)
                      throws TupleQueryResultHandlerException

Description copied from interface: QueryResultHandler

Indicates the start of a sequence of Solutions. The supplied bindingNames are an indication of the values that are in the Solutions. For example, a SPARQL query like select ?X ?Y where { ?X ?P ?Y } will have binding names X and Y.

Specified by:

startQueryResult in interface QueryResultHandler

Parameters:

bindingNames - An ordered set of binding names.

Throws:

TupleQueryResultHandlerException - If there was an error during the starting of the query result handler. This exception may be thrown if the QueryResultHandler.handleBoolean(boolean) method was called before this method and the handler cannot process both boolean and tuple results simultaneously.

handleSolution

public void handleSolution(BindingSet bindingSet)
                    throws TupleQueryResultHandlerException

Description copied from interface: QueryResultHandler

Handles a solution.

Specified by:

handleSolution in interface QueryResultHandler

Parameters:

bindingSet - A single set of tuple results, with binding names bound to values. Each of the binding names in the solution must have previously been registered with the QueryResultHandler.startQueryResult(List) method.

Throws:

TupleQueryResultHandlerException - If there was an error during the handling of the query solution. This exception may be thrown if the QueryResultHandler.handleBoolean(boolean) method was called before this method and the handler cannot process both boolean and tuple results simultaneously.

endQueryResult

public void endQueryResult()
                    throws TupleQueryResultHandlerException

Description copied from interface: QueryResultHandler

Indicates the end of a sequence of solutions.

Specified by:

endQueryResult in interface QueryResultHandler

Throws:

TupleQueryResultHandlerException - If there was an error during the ending of the query result handler. This exception may be thrown if the QueryResultHandler.handleBoolean(boolean) method was called before this method and the handler cannot process both boolean and tuple results simultaneously.

handleBoolean

public void handleBoolean(boolean value)
                   throws QueryResultHandlerException

Description copied from interface: QueryResultHandler

Handles the specified boolean value.

Specified by:

handleBoolean in interface QueryResultHandler

Parameters:

value - The boolean value to handle.

Throws:

QueryResultHandlerException - If there was an error during the handling of this value. This exception may be thrown if the QueryResultHandler.startQueryResult(List), QueryResultHandler.handleSolution(BindingSet) or QueryResultHandler.endQueryResult() methods were called before this method was called, and the handler cannot process both boolean and tuple results simultaneously.

handleLinks

public void handleLinks(List<String> linkUrls)
                 throws QueryResultHandlerException

Description copied from interface: QueryResultHandler

Handles the links elements which are present in SPARQL Results JSON and SPARQL Results XML documents in the header.

NOTE: If the format does not support links, it must silently ignore a call to this method.

An accumulating handler should accumulate these links.

Specified by:

handleLinks in interface QueryResultHandler

Parameters:

linkUrls - The URLs of the links to handle.

Throws:

QueryResultHandlerException - If there was an error handling the set of link URLs. This error is not thrown in cases where links are not supported.

See Also:

• "link"