Package org.apache.commons.rdf.api

Interface Graph

All Superinterfaces:

java.lang.AutoCloseable, GraphLike<Triple>

All Known Subinterfaces:

JsonLdGraph, JsonLdUnionGraph, RDF4JGraph

All Known Implementing Classes:

DatasetGraphView, GraphImpl, JsonLdGraphImpl, JsonLdUnionGraphImpl, ModelGraphImpl, RepositoryGraphImpl

public interface Graph
extends java.lang.AutoCloseable, GraphLike<Triple>

An RDF 1.1 Graph, a set of RDF triples, as defined by RDF-1.1 Concepts and Abstract Syntax, a W3C Recommendation published on 25 February 2014.

See Also:

RDF.createGraph()

Method Summary

Modifier and Type	Method	Description
void	add(BlankNodeOrIRI subject, IRI predicate, RDFTerm object)	Adds a triple to the graph, possibly mapping any of the components to those supported by this Graph.
void	add(Triple triple)	Adds a triple to the graph, possibly mapping any of the components of the Triple to those supported by this Graph.
void	clear()	Clears the graph, removing all triples.
default void	close()	Closes the graph, relinquishing any underlying resources.
boolean	contains(BlankNodeOrIRI subject, IRI predicate, RDFTerm object)	Checks if graph contains a pattern of triples.
boolean	contains(Triple triple)	Checks if graph contains triple.
default java.util.stream.Stream<? extends Triple>	getTriples()	Deprecated.
default java.util.stream.Stream<? extends Triple>	getTriples(BlankNodeOrIRI subject, IRI predicate, RDFTerm object)	Deprecated.
default java.lang.Iterable<Triple>	iterate()	Gets an Iterable for iterating over all triples in the graph.
default java.lang.Iterable<Triple>	iterate(BlankNodeOrIRI subject, IRI predicate, RDFTerm object)	Gets an Iterable for iterating over the triples in the graph that match the pattern.
void	remove(BlankNodeOrIRI subject, IRI predicate, RDFTerm object)	Removes a concrete pattern of triples from the graph.
void	remove(Triple triple)	Removes a concrete triple from the graph.
long	size()	Number of triples contained by the graph.
java.util.stream.Stream<? extends Triple>	stream()	Gets all triples contained by the graph.
java.util.stream.Stream<? extends Triple>	stream(BlankNodeOrIRI subject, IRI predicate, RDFTerm object)	Gets all triples contained by the graph matched with the pattern.

Method Detail

add

void add(Triple triple)

Adds a triple to the graph, possibly mapping any of the components of the Triple to those supported by this Graph.

Specified by:

add in interface GraphLike<Triple>

Parameters:

triple - The triple to add

add

void add(BlankNodeOrIRI subject,
         IRI predicate,
         RDFTerm object)

Adds a triple to the graph, possibly mapping any of the components to those supported by this Graph.

Parameters:

subject - The triple subject

predicate - The triple predicate

object - The triple object

contains

boolean contains(Triple triple)

Checks if graph contains triple.

Specified by:

contains in interface GraphLike<Triple>

Parameters:

triple - The triple to check.

Returns:

True if the Graph contains the given Triple.

contains

boolean contains(BlankNodeOrIRI subject,
                 IRI predicate,
                 RDFTerm object)

Checks if graph contains a pattern of triples.

Parameters:

subject - The triple subject (null is a wildcard)

predicate - The triple predicate (null is a wildcard)

object - The triple object (null is a wildcard)

Returns:

True if the Graph contains any Triples that match the given pattern.

close

default void close()
            throws java.lang.Exception

Closes the graph, relinquishing any underlying resources.

For example, this would close any open file and network streams and free database locks held by the Graph implementation.

The behaviour of the other Graph methods are undefined after closing the graph.

Implementations might not need close(), hence the default implementation does nothing.

Specified by:

close in interface java.lang.AutoCloseable

Throws:

java.lang.Exception

remove

void remove(Triple triple)

Removes a concrete triple from the graph.

Specified by:

remove in interface GraphLike<Triple>

Parameters:

triple - triple to remove

remove

void remove(BlankNodeOrIRI subject,
            IRI predicate,
            RDFTerm object)

Removes a concrete pattern of triples from the graph.

Parameters:

subject - The triple subject (null is a wildcard)

predicate - The triple predicate (null is a wildcard)

object - The triple object (null is a wildcard)

clear

void clear()

Clears the graph, removing all triples.

Specified by:

clear in interface GraphLike<Triple>

size

long size()

Number of triples contained by the graph.

The count of a set does not include duplicates, consistent with the Triple.equals(Object) equals method for each Triple.

Specified by:

size in interface GraphLike<Triple>

Returns:

The number of triples in the graph

stream

java.util.stream.Stream<? extends Triple> 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 each Triple.

The behaviour of the Stream is not specified if add(Triple), remove(Triple) or clear() are called on the Graph before it terminates.

Implementations may throw ConcurrentModificationException from Stream methods if they detect a conflict while the Stream is active.

Specified by:

stream in interface GraphLike<Triple>

Returns:

A Stream over all of the triples in the graph

Since:

0.3.0-incubating

stream

java.util.stream.Stream<? extends Triple> stream(BlankNodeOrIRI subject,
                                                 IRI predicate,
                                                 RDFTerm object)

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 each Triple.

The behaviour of the Stream is not specified if add(Triple), remove(Triple) or clear() are called on the Graph before it terminates.

Implementations may throw ConcurrentModificationException from Stream methods if they detect a conflict while the Stream is active.

Parameters:

subject - The triple subject (null is a wildcard)

predicate - The triple predicate (null is a wildcard)

object - The triple object (null is a wildcard)

Returns:

A Stream over the matched triples.

Since:

0.3.0-incubating

getTriples

@Deprecated
default java.util.stream.Stream<? extends Triple> getTriples()

Deprecated.

This method is deprecated, use the equivalent method stream() instead.

Returns:

A Stream over all triples.

getTriples

@Deprecated
default java.util.stream.Stream<? extends Triple> getTriples(BlankNodeOrIRI subject,
                                                             IRI predicate,
                                                             RDFTerm object)

Deprecated.

This method is deprecated, use the equivalent method stream(BlankNodeOrIRI, IRI, RDFTerm) instead.

Parameters:

subject - The triple subject (null is a wildcard)

predicate - The triple predicate (null is a wildcard)

object - The triple object (null is a wildcard)

Returns:

A Stream over the matched triples.

iterate

default java.lang.Iterable<Triple> iterate()
                                    throws java.util.ConcurrentModificationException,
                                           java.lang.IllegalStateException

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 if add(Triple), remove(Triple) or clear(), are called on the Graph before it terminates. It is undefined if the returned Iterator supports the Iterator.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. A IllegalStateException may be thrown on attempt to reuse the Iterable.

The default implementation of this method will call stream() to return its BaseStream.iterator().

Specified by:

iterate in interface GraphLike<Triple>

Returns:

A Iterable that returns Iterator over all of the triples in the graph

Throws:

java.lang.IllegalStateException - if the Iterable has been reused

java.util.ConcurrentModificationException - if a concurrency conflict occurs while the Iterator is active.

iterate

default java.lang.Iterable<Triple> iterate(BlankNodeOrIRI subject,
                                           IRI predicate,
                                           RDFTerm object)
                                    throws java.util.ConcurrentModificationException,
                                           java.lang.IllegalStateException

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 add(Triple), remove(Triple) or clear(), are called on the Graph before it terminates. It is undefined if the returned Iterator supports the Iterator.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. A IllegalStateException may be thrown on attempt to reuse the Iterable.

The default implementation of this method will call stream(BlankNodeOrIRI, IRI, RDFTerm) to return its BaseStream.iterator().

Parameters:

subject - The triple subject (null is a wildcard)

predicate - The triple predicate (null is a wildcard)

object - The triple object (null is a wildcard)

Returns:

A Iterable that returns Iterator over the matching triples in the graph

Throws:

java.lang.IllegalStateException - if the Iterable has been reused

java.util.ConcurrentModificationException - if a concurrency conflict occurs while the Iterator is active.