Class BackgroundGraphResult

java.lang.Object

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

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

org.eclipse.rdf4j.query.impl.BackgroundGraphResult

All Implemented Interfaces:

AutoCloseable, Iterable<Statement>, Runnable, Iterator<Statement>, CloseableIteration<Statement>, GraphQueryResult, QueryResult<Statement>, RDFHandler

public class BackgroundGraphResult
extends IterationWrapper<Statement>
implements GraphQueryResult, Runnable, RDFHandler

Provides concurrent access to statements as they are being parsed when instances of this class are run as Threads.

Author:

James Leigh

Field Summary

Fields inherited from class IterationWrapper

wrappedIter

Modifier and Type	Field	Description
protected final CloseableIteration<? extends Statement>	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
BackgroundGraphResult(QueueCursor<Statement> queue, RDFParser parser, InputStream in, Charset charset, String baseURI)
BackgroundGraphResult(RDFParser parser, InputStream in, Charset charset, String baseURI)

Method Summary

Modifier and Type	Method	Description
void	endRDF()	Signals the end of the RDF data.
Map<String,String>	getNamespaces()	Retrieves relevant namespaces from the query result.
protected void	handleClose()	Closes this Iteration and also closes the wrapped Iteration if it is a CloseableIteration.
void	handleComment(String comment)	Handles a comment.
void	handleNamespace(String prefix, String uri)	Handles a namespace declaration/definition.
void	handleStatement(Statement st)	Handles a statement.
void	run()
void	startRDF()	Signals the start of the RDF data.

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.
Statement	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<Statement>	iterator()
Statement	next()	Returns the next element in the query result.
default Stream<Statement>	stream()	Convert the result elements to a Java Stream.

Constructor Details

BackgroundGraphResult

public BackgroundGraphResult(RDFParser parser,
 InputStream in,
 Charset charset,
 String baseURI)

BackgroundGraphResult

public BackgroundGraphResult(QueueCursor<Statement> queue,
 RDFParser parser,
 InputStream in,
 Charset charset,
 String baseURI)

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<Statement>

Throws:

QueryEvaluationException

run

public void run()

Specified by:

run in interface Runnable

startRDF

public void startRDF()
              throws RDFHandlerException

Description copied from interface: RDFHandler

Signals the start of the RDF data. This method is called before any data is reported.

Specified by:

startRDF in interface RDFHandler

Throws:

RDFHandlerException - If the RDF handler has encountered an unrecoverable error.

getNamespaces

public Map<String,String> getNamespaces()

Description copied from interface: GraphQueryResult

Retrieves relevant namespaces from the query result.
The contents of the Map may be modified after it is returned, as the initial return may be performed when the first RDF Statement is encountered.

Specified by:

getNamespaces in interface GraphQueryResult

Returns:

a Map<String, String> object containing (prefix, namespace) pairs.

handleComment

public void handleComment(String comment)
                   throws RDFHandlerException

Description copied from interface: RDFHandler

Handles a comment.

Specified by:

handleComment in interface RDFHandler

Parameters:

comment - The comment.

Throws:

RDFHandlerException - If the RDF handler has encountered an unrecoverable error.

handleNamespace

public void handleNamespace(String prefix,
 String uri)
                     throws RDFHandlerException

Description copied from interface: RDFHandler

Handles a namespace declaration/definition. A namespace declaration associates a (short) prefix string with the namespace's URI. The prefix for default namespaces, which do not have an associated prefix, are represented as empty strings.

Specified by:

handleNamespace in interface RDFHandler

Parameters:

prefix - The prefix for the namespace, or an empty string in case of a default namespace.

uri - The URI that the prefix maps to.

Throws:

RDFHandlerException - If the RDF handler has encountered an unrecoverable error.

handleStatement

public void handleStatement(Statement st)
                     throws RDFHandlerException

Description copied from interface: RDFHandler

Handles a statement.

Specified by:

handleStatement in interface RDFHandler

Parameters:

st - The statement.

Throws:

RDFHandlerException - If the RDF handler has encountered an unrecoverable error.

endRDF

public void endRDF()
            throws RDFHandlerException

Description copied from interface: RDFHandler

Signals the end of the RDF data. This method is called when all data has been reported.

Specified by:

endRDF in interface RDFHandler

Throws:

RDFHandlerException - If the RDF handler has encountered an unrecoverable error.