Package org.eclipse.rdf4j.repository.util

Class Connections

java.lang.Object

org.eclipse.rdf4j.repository.util.Connections

public class Connections
extends Object

Convenience functions for use with RepositoryConnections.

Author:

Jeen Broekstra

Constructor Summary

Constructors

Constructor	Description
Connections()

Method Summary

Modifier and Type	Method	Description
static void	consumeRDFCollection(RepositoryConnection conn, Resource head, Consumer<Statement> collectionConsumer, Resource... contexts)	Retrieve all Statements that together form the RDF Collection starting with the supplied start resource and send them to the supplied Consumer.
static <C extends Collection<Statement>> C	getRDFCollection(RepositoryConnection conn, Resource head, C statementCollection, Resource... contexts)	Retrieve all Statements that together form the RDF Collection starting with the supplied starting resource.
static Optional<Statement>	getStatement(RepositoryConnection conn, Resource subject, IRI predicate, Value object, Resource... contexts)	Retrieve a single Statement matching with the supplied subject, predicate, object and context(s) from the given RepositoryConnection.

Methods inherited from class java.lang.Object

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

Constructor Detail

Connections

public Connections()

Method Detail

consumeRDFCollection

public static void consumeRDFCollection(RepositoryConnection conn,
                                        Resource head,
                                        Consumer<Statement> collectionConsumer,
                                        Resource... contexts)
                                 throws RepositoryException

Retrieve all Statements that together form the RDF Collection starting with the supplied start resource and send them to the supplied Consumer.

Parameters:

conn - the RepositoryConnection to use for statement retrieval.

head - the start resource of the RDF Collection. May not be null.

collectionConsumer - a Consumer function to which all retrieved statements will be reported. May not be null.

contexts - the context(s) from which to read the RDF Collection. This argument is an optional vararg and can be left out.

Throws:

RepositoryException - if an error occurred while reading the collection statements, for example if a cycle is detected in the RDF collection, or some other anomaly which makes it non-wellformed.

See Also:

RDFCollections, RDF Schema 1.1 section on Collection vocabulary.

getRDFCollection

public static <C extends Collection<Statement>> C getRDFCollection(RepositoryConnection conn,
                                                                   Resource head,
                                                                   C statementCollection,
                                                                   Resource... contexts)
                                                            throws RepositoryException

Retrieve all Statements that together form the RDF Collection starting with the supplied starting resource.

Parameters:

conn - the RepositoryConnection to use for statement retrieval.

head - the start resource of the RDF Collection. May not be null.

statementCollection - a Collection of Statements (for example, a Model) to which all retrieved statements will be reported. May not be null.

contexts - the context(s) from which to read the RDF Collection. This argument is an optional vararg and can be left out.

Returns:

the input statement collection, with the statements forming the retrieved RDF Collection added.

Throws:

RepositoryException - if an error occurred while reading the collection statements, for example if a cycle is detected in the RDF collection, or some other anomaly which makes it non-wellformed.

See Also:

RDFCollections, RDF Schema 1.1 section on Collection vocabulary.

getStatement

public static Optional<Statement> getStatement(RepositoryConnection conn,
                                               Resource subject,
                                               IRI predicate,
                                               Value object,
                                               Resource... contexts)
                                        throws RepositoryException

Retrieve a single Statement matching with the supplied subject, predicate, object and context(s) from the given RepositoryConnection. If more than one Statement matches, any one Statement is selected and returned.

Parameters:

conn - the RepositoryConnection from which to retrieve the statement.

subject - the subject to which the statement should match. May be null.

predicate - the predicate to which the statement should match. May be null.

object - the object to which the statement should match. May be null .

contexts - the context(s) from which to read the Statement. This argument is an optional vararg and can be left out.

Returns:

an Optional of Statement. If no matching Statement was found, Optional.empty() is returned.

Throws:

RepositoryException