org.apache.commons.rdf.rdf4j

Interface RDF4JDataset

All Superinterfaces:

AutoCloseable, Dataset, GraphLike<Quad>, RDF4JGraphLike<Quad>

public interface RDF4JDataset
extends Dataset, RDF4JGraphLike<Quad>

Marker interface for RDF4J implementations of Dataset.

See Also:

RDF4J.createDataset(), RDF4J.asDataset(org.eclipse.rdf4j.repository.Repository, Option...)

Method Summary

Modifier and Type	Method and Description
Stream<BlankNodeOrIRI>	getGraphNames()
ClosableIterable<Quad>	iterate()
ClosableIterable<Quad>	iterate(Optional<BlankNodeOrIRI> graphName, BlankNodeOrIRI subject, IRI predicate, RDFTerm object)
Stream<RDF4JQuad>	stream()
Stream<RDF4JQuad>	stream(Optional<BlankNodeOrIRI> graphName, BlankNodeOrIRI subject, IRI predicate, RDFTerm object)

Methods inherited from interface org.apache.commons.rdf.api.Dataset

add, add, clear, close, contains, contains, getGraph, getGraph, remove, remove, size

Methods inherited from interface org.apache.commons.rdf.rdf4j.RDF4JGraphLike

asModel, asRepository

Method Detail

stream

Stream<RDF4JQuad> stream()

Note that for datasets backed by a repository (RDF4JGraphLike.asRepository() is present), the stream must be closed with BaseStream.close().

This can generally achieved using a try-with-resources block, e.g.:

 int subjects;
 try (Stream<RDF4JQuad> s : graph.stream()) {
   subjects = s.map(RDF4JQuad::getSubject).distinct().count()
 }
 

Specified by:

stream in interface Dataset

Specified by:

stream in interface GraphLike<Quad>

stream

Stream<RDF4JQuad> stream(Optional<BlankNodeOrIRI> graphName,
                         BlankNodeOrIRI subject,
                         IRI predicate,
                         RDFTerm object)

Note that for datasets backed by a repository (RDF4JGraphLike.asRepository() is present), the stream must be closed with BaseStream.close().

This can generally achieved using a try-with-resources block, e.g.:

 int subjects;
 try (Stream<RDF4JQuad> s : graph.stream()) {
   subjects = s.map(RDF4JQuad::getSubject).distinct().count()
 }
 

Specified by:

stream in interface Dataset

getGraphNames

Stream<BlankNodeOrIRI> getGraphNames()

Note that for datasets backed by a repository (RDF4JGraphLike.asRepository() is present), the stream must be closed with BaseStream.close().

This can generally achieved using a try-with-resources block, e.g.:

 int graphs;
 try (Stream<BlankNodeOrIRI> s : graph.stream()) {
   graphs = s.count()
 }
 

Specified by:

getGraphNames in interface Dataset

iterate

ClosableIterable<Quad> iterate()

Note that for datasets backed by a repository (RDF4JGraphLike.asRepository() is present), the iterable must be closed with AutoCloseable.close().

This can generally achieved using a try-with-resources block, e.g.:

 try (ClosableIterable<Quad> s : graph.iterate()) {
   for (Quad q : quads) {
       return q; // OK to terminate for-loop early
   }
 }
 

If you don't use a try-with-resources block, the iterator will attempt to close the ClosableIterable when reaching the end of the iteration.

Specified by:

iterate in interface Dataset

Specified by:

iterate in interface GraphLike<Quad>

iterate

ClosableIterable<Quad> iterate(Optional<BlankNodeOrIRI> graphName,
                               BlankNodeOrIRI subject,
                               IRI predicate,
                               RDFTerm object)

Note that for datasets backed by a repository (RDF4JGraphLike.asRepository() is present), the iterable must be closed with AutoCloseable.close().

This can generally achieved using a try-with-resources block, e.g.:

 try (ClosableIterable<Quad> s : graph.iterate(g,s,p,o)) {
   for (Quad q : quads) {
       return q; // OK to terminate for-loop early
   }
 }
 

If you don't use a try-with-resources block, the iterator will attempt to close the ClosableIterable when reaching the end of the iteration.

Specified by:

iterate in interface Dataset