Interface RDF4JGraph
- All Superinterfaces:
AutoCloseable
,Graph
,GraphLike<Triple>
,RDF4JGraphLike<Triple>
- All Known Implementing Classes:
ModelGraphImpl
,RepositoryGraphImpl
- See Also:
-
Method Summary
Modifier and TypeMethodDescriptionReturn a copy of the context mask as aSet
ofRDF4JBlankNodeOrIRI
graph names.iterate()
Gets an Iterable for iterating over all triples in the graph.iterate
(BlankNodeOrIRI subject, IRI predicate, RDFTerm object) Gets an Iterable for iterating over the triples in the graph that match the pattern.stream()
Gets all triples contained by the graph.stream
(BlankNodeOrIRI subject, IRI predicate, RDFTerm object) Gets all triples contained by the graph matched with the pattern.Methods inherited from interface org.apache.commons.rdf.api.Graph
add, add, clear, close, contains, contains, getTriples, getTriples, remove, remove, size
Methods inherited from interface org.apache.commons.rdf.rdf4j.RDF4JGraphLike
asModel, asRepository
-
Method Details
-
getContextMask
Set<RDF4JBlankNodeOrIRI> getContextMask()Return a copy of the context mask as aSet
ofRDF4JBlankNodeOrIRI
graph names.If the set is not
Set.isEmpty()
, the mask determines which contexts in the corresponding RDF4JModel
orRepository
that this graph reflect. Modifications to the graph (e.g.Graph.add(Triple)
will be performed for all the specified contexts, while retrieval (e.g.Graph.contains(Triple)
) will succeed if the triple is in at least one of the specified contexts.The context mask array may contain
null
, indicating the default context (the default graph in RDF datasets).If the context mask is
Set.isEmpty()
, then this is a union graph which triples reflect statements in any contexts. Triples added to the graph will be added in the default context, e.g. equivalent tonew Resource[1]{null}
) in RDF4J.Note that the context mask itself cannot be
null
.The returned set is an immutable copy; to specify a different mask, use
RDF4J.asGraph(Repository, Set, Option...)
- Returns:
- The context mask as a set of
BlankNodeOrIRI
graph names, which may contain the valuenull
.
-
stream
Stream<RDF4JTriple> stream()Gets all triples contained by the graph.
The iteration does not contain any duplicate triples, as determined by the
Triple.equals(Object)
method for eachTriple
.The behaviour of the
Stream
is not specified ifGraph.add(Triple)
,Graph.remove(Triple)
orGraph.clear()
are called on theGraph
before it terminates.Implementations may throw
ConcurrentModificationException
from Stream methods if they detect a conflict while the Stream is active.Note that for graphs backed by a repository (
RDF4JGraphLike.asRepository()
is present), the stream must be closed withBaseStream.close()
.This can generally achieved using a try-with-resources block, e.g.:
int subjects; try (Stream<RDF4JTriple> s : graph.stream()) { subjects = s.map(RDF4JTriple::getSubject).distinct().count() }
-
stream
Gets all triples contained by the graph matched with the pattern.The iteration does not contain any duplicate triples, as determined by the
Triple.equals(Object)
method for eachTriple
.The behaviour of the
Stream
is not specified ifGraph.add(Triple)
,Graph.remove(Triple)
orGraph.clear()
are called on theGraph
before it terminates.Implementations may throw
ConcurrentModificationException
from Stream methods if they detect a conflict while the Stream is active.Note that for graphs backed by a repository (
RDF4JGraphLike.asRepository()
is present), the stream must be closed withBaseStream.close()
.This can generally achieved using a try-with-resources block, e.g.:
int subjects; try (Stream<RDF4JTriple> s : graph.stream(s,p,o)) { subjects = s.map(RDF4JTriple::getSubject).distinct().count() }
-
iterate
Gets an Iterable for iterating over all triples in the graph.This method is meant to be used with a Java for-each loop, e.g.:
for (Triple t : graph.iterate()) { System.out.println(t); }
The behaviour of the iterator is not specified ifGraph.add(Triple)
,Graph.remove(Triple)
orGraph.clear()
, are called on theGraph
before it terminates. It is undefined if the returnedIterator
supports theIterator.remove()
method.Implementations may throw
ConcurrentModificationException
from Iterator methods if they detect a concurrency conflict while the Iterator is active.The
Iterable.iterator()
must only be called once, that is the Iterable must only be iterated over once. AIllegalStateException
may be thrown on attempt to reuse the Iterable.The default implementation of this method will call
Graph.stream()
to return itsBaseStream.iterator()
.Note that for graphs backed by a repository (
RDF4JGraphLike.asRepository()
is present), the iterable must be closed withAutoCloseable.close()
.This can generally achieved using a try-with-resources block, e.g.:
try (ClosableIterable<Triple> s : graph.iterate()) { for (Triple t : triples) { return t; // 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 interfaceGraph
- Specified by:
iterate
in interfaceGraphLike<Triple>
- Returns:
- A
Iterable
that returnsIterator
over all of the triples in the graph - Throws:
ConcurrentModificationException
- if a concurrency conflict occurs while the Iterator is active.IllegalStateException
- if theIterable
has been reused
-
iterate
Gets an Iterable for iterating over the triples in the graph that match the pattern.This method is meant to be used with a Java for-each loop, e.g.:
IRI alice = factory.createIRI("http://example.com/alice"); IRI knows = factory.createIRI("http://xmlns.com/foaf/0.1/"); for (Triple t : graph.iterate(alice, knows, null)) { System.out.println(t.getObject()); }
The behaviour of the iterator is not specified if
Graph.add(Triple)
,Graph.remove(Triple)
orGraph.clear()
, are called on theGraph
before it terminates. It is undefined if the returnedIterator
supports theIterator.remove()
method.Implementations may throw
ConcurrentModificationException
from Iterator methods if they detect a concurrency conflict while the Iterator is active.The
Iterable.iterator()
must only be called once, that is the Iterable must only be iterated over once. AIllegalStateException
may be thrown on attempt to reuse the Iterable.The default implementation of this method will call
Graph.stream(BlankNodeOrIRI, IRI, RDFTerm)
to return itsBaseStream.iterator()
.Note that for graphs backed by a repository (
RDF4JGraphLike.asRepository()
is present), the iterable must be closed withAutoCloseable.close()
.This can generally achieved using a try-with-resources block, e.g.:
try (ClosableIterable<Triple> s : graph.iterate(s,p,o)) { for (Triple t : triples) { return t; // 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.
-