org.apache.commons.rdf.rdf4j

Class RDF4J

java.lang.Object

org.apache.commons.rdf.rdf4j.RDF4J

All Implemented Interfaces:

RDF

public final class RDF4J
extends Object
implements RDF

RDF4J implementation of RDF.

The RDF4J() constructor uses a SimpleValueFactory to create corresponding RDF4J Value instances. Alternatively, this factory can be constructed with a different ValueFactory using RDF4J(ValueFactory).

asRDFTerm(Value) can be used to convert any RDF4J Value to an RDFTerm. Note that adapted BNodes are considered equal if they are converted with the same RDF4J instance and have the same BNode.getID().

createGraph() creates a new Graph backed by LinkedHashModel. To use other models, see asGraph(Model).

To adapt a RDF4J Repository as a Dataset or Graph, use asDataset(Repository, Option...) or asGraph(Repository, Option...).

asTriple(Statement) can be used to convert a RDF4J Statement to a Commons RDF Triple, and equivalent asQuad(Statement) to convert a Quad.

To convert any Triple or Quad to to RDF4J Statement, use asStatement(TripleLike). This recognises previously converted RDF4JTriples and RDF4JQuads without re-converting their RDF4JTripleLike.asStatement().

Likewise, asValue(RDFTerm) can be used to convert any Commons RDF RDFTerm to a corresponding RDF4J Value. This recognises previously converted RDF4JTerms without re-converting their RDF4JTerm.asValue().

For the purpose of BlankNode equivalence, this factory contains an internal UUID salt that is used by adapter methods like asQuad(Statement), asTriple(Statement), asRDFTerm(Value) as well as createBlankNode(String). As RDF4J BNode instances from multiple repositories or models may have the same BNode.getID(), converting them with the above methods might cause accidental BlankNode equivalence. Note that the Graph and Dataset adapter methods like asDataset(Repository, Option...) and asGraph(Repository, Option...) therefore uses a unique RDF4J internally.

See Also:

RDF

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static class	RDF4J.Option

Constructor Summary

Constructors

Constructor and Description
RDF4J() Construct an RDF4J.
RDF4J(UUID salt) Construct an RDF4J.
RDF4J(org.eclipse.rdf4j.model.ValueFactory valueFactory) Construct an RDF4J.
RDF4J(org.eclipse.rdf4j.model.ValueFactory valueFactory, UUID salt) Construct an RDF4J.

Method Summary

Modifier and Type	Method and Description
RDF4JDataset	asDataset(org.eclipse.rdf4j.repository.Repository repository, RDF4J.Option... options) Adapt an RDF4J Repository as a Commons RDF Dataset.
RDF4JGraph	asGraph(org.eclipse.rdf4j.model.Model model) Adapt an RDF4J Model as a Commons RDF Graph.
RDF4JGraph	asGraph(org.eclipse.rdf4j.repository.Repository repository, RDF4J.Option... options) Adapt an RDF4J Repository as a Commons RDF Graph.
RDF4JGraph	asGraph(org.eclipse.rdf4j.repository.Repository repository, Set<? extends BlankNodeOrIRI> contexts, RDF4J.Option... option) Adapt an RDF4J Repository as a Commons RDF Graph.
RDF4JGraph	asGraphUnion(org.eclipse.rdf4j.repository.Repository repository, RDF4J.Option... options) Adapt an RDF4J Repository as a Commons RDF Graph.
RDF4JQuad	asQuad(org.eclipse.rdf4j.model.Statement statement) Adapt a RDF4J Statement as a Commons RDF Quad.
RDF4JBlankNode	asRDFTerm(org.eclipse.rdf4j.model.BNode value) Adapt a RDF4J BNode as a Commons RDF BlankNode
RDF4JIRI	asRDFTerm(org.eclipse.rdf4j.model.IRI value) Adapt a RDF4J IRI as a Commons RDF IRI
RDF4JLiteral	asRDFTerm(org.eclipse.rdf4j.model.Literal value) Adapt a RDF4J Literal as a Commons RDF Literal
RDF4JBlankNodeOrIRI	asRDFTerm(org.eclipse.rdf4j.model.Resource value) Adapt a RDF4J Resource as a Commons RDF BlankNodeOrIRI
RDF4JTerm	asRDFTerm(org.eclipse.rdf4j.model.Value value) Adapt a RDF4J Value as a Commons RDF RDFTerm.
static RDF4JTerm	asRDFTerm(org.eclipse.rdf4j.model.Value value, UUID salt) Adapt a RDF4J Value as a Commons RDF RDFTerm.
org.eclipse.rdf4j.model.Statement	asStatement(TripleLike tripleLike) Adapt a Commons RDF Triple or Quad as a RDF4J Statement.
RDF4JTriple	asTriple(org.eclipse.rdf4j.model.Statement statement) Adapt a RDF4J Statement as a Commons RDF Triple.
org.eclipse.rdf4j.model.Value	asValue(RDFTerm term) Adapt a Commons RDF RDFTerm as a RDF4J Value.
RDF4JBlankNode	createBlankNode() Create a new blank node.
RDF4JBlankNode	createBlankNode(String name) Create a blank node based on the given name.
RDF4JDataset	createDataset() Create a new dataset.
RDF4JGraph	createGraph() Create a new graph.
RDF4JIRI	createIRI(String iri) Create an IRI from a (possibly escaped) String.
RDF4JLiteral	createLiteral(String lexicalForm) Create a simple literal.
Literal	createLiteral(String lexicalForm, IRI dataType) Create a literal with the specified data type.
Literal	createLiteral(String lexicalForm, String languageTag) Create a language-tagged literal.
Quad	createQuad(BlankNodeOrIRI graphName, BlankNodeOrIRI subject, IRI predicate, RDFTerm object) Create a quad.
RDF4JTriple	createTriple(BlankNodeOrIRI subject, IRI predicate, RDFTerm object) Create a triple.
org.eclipse.rdf4j.model.ValueFactory	getValueFactory()

Methods inherited from class java.lang.Object

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

Constructor Detail

RDF4J

public RDF4J()

Construct an RDF4J.

RDF4J

public RDF4J(org.eclipse.rdf4j.model.ValueFactory valueFactory)

Construct an RDF4J.

This constructor is intended for use with the value factory from Repository.getValueFactory() when using Repository-based graphs and datasets.

Parameters:

valueFactory - The RDF4J ValueFactory to use

RDF4J

public RDF4J(UUID salt)

Construct an RDF4J.

This constructor may be used if reproducible BlankNode.uniqueReference() in BlankNode is desirable.

Parameters:

salt - An UUID salt to be used by any created BlankNodes for the purpose of BlankNode.uniqueReference()

RDF4J

public RDF4J(org.eclipse.rdf4j.model.ValueFactory valueFactory,
             UUID salt)

Construct an RDF4J.

This constructor may be used if reproducible BlankNode.uniqueReference() in BlankNode is desirable.

Parameters:

valueFactory - The RDF4J ValueFactory to use

salt - An UUID salt to be used by any created BlankNodes for the purpose of BlankNode.uniqueReference()

Method Detail

asQuad

public RDF4JQuad asQuad(org.eclipse.rdf4j.model.Statement statement)

Adapt a RDF4J Statement as a Commons RDF Quad.

For the purpose of BlankNode equivalence, this method will use an internal salt UUID that is unique per instance of RDF4J.

NOTE: If combining RDF4J Statements multiple repositories or models, then their BNodes may have the same BNode.getID(), which with this method would become equivalent according to BlankNode.equals(Object) and BlankNode.uniqueReference(), unless a separate RDF4J instance is used per RDF4J repository/model.

Parameters:

statement - The statement to convert

Returns:

A RDF4JQuad that is equivalent to the statement

asRDFTerm

public RDF4JTerm asRDFTerm(org.eclipse.rdf4j.model.Value value)

Adapt a RDF4J Value as a Commons RDF RDFTerm.

The value will be of the same kind as the term, e.g. a BNode is converted to a BlankNode, a IRI is converted to a IRI and a Literal. is converted to a Literal

For the purpose of BlankNode equivalence, this method will use an internal salt UUID that is unique per instance of RDF4J.

NOTE: If combining RDF4J values from multiple repositories or models, then their BNodes may have the same BNode.getID(), which with this method would become equivalent according to BlankNode.equals(Object) and BlankNode.uniqueReference(), unless a separate RDF4J instance is used per RDF4J repository/model.

Parameters:

value - The RDF4J Value to convert.

Returns:

A RDFTerm that corresponds to the RDF4J value

Throws:

IllegalArgumentException - if the value is not a BNode, Literal or IRI

asRDFTerm

public RDF4JBlankNode asRDFTerm(org.eclipse.rdf4j.model.BNode value)

Adapt a RDF4J BNode as a Commons RDF BlankNode

For the purpose of BlankNode equivalence, this method will use an internal salt UUID that is unique per instance of RDF4J.

NOTE: If combining RDF4J values from multiple repositories or models, then their BNodes may have the same BNode.getID(), which with this method would become equivalent according to BlankNode.equals(Object) and BlankNode.uniqueReference(), unless a separate RDF4J instance is used per RDF4J repository/model.

Parameters:

value - The RDF4J BNode to convert.

Returns:

A RDF4JBlankNode that corresponds to the RDF4J BNode

asRDFTerm

public RDF4JLiteral asRDFTerm(org.eclipse.rdf4j.model.Literal value)

Adapt a RDF4J Literal as a Commons RDF Literal

Parameters:

value - The RDF4J Literal to convert.

Returns:

A RDF4JLiteral that corresponds to the RDF4J literal

asRDFTerm

public RDF4JIRI asRDFTerm(org.eclipse.rdf4j.model.IRI value)

Adapt a RDF4J IRI as a Commons RDF IRI

Parameters:

value - The RDF4J Value to convert.

Returns:

A RDF4JIRI that corresponds to the RDF4J IRI

asRDFTerm

public RDF4JBlankNodeOrIRI asRDFTerm(org.eclipse.rdf4j.model.Resource value)

Adapt a RDF4J Resource as a Commons RDF BlankNodeOrIRI

Parameters:

value - The RDF4J Value to convert.

Returns:

A RDF4JBlankNodeOrIRI that corresponds to the RDF4J Resource

asRDFTerm

public static RDF4JTerm asRDFTerm(org.eclipse.rdf4j.model.Value value,
                                  UUID salt)

Adapt a RDF4J Value as a Commons RDF RDFTerm.

The value will be of the same kind as the term, e.g. a BNode is converted to a BlankNode, a IRI is converted to a IRI and a Literal. is converted to a Literal

Parameters:

value - The RDF4J Value to convert.

salt - A UUID salt to use for uniquely mapping any BNodes. The salt should typically be the same for multiple statements in the same Repository or Model to ensure BlankNode.equals(Object) and BlankNode.uniqueReference() works as intended.

Returns:

A RDFTerm that corresponds to the RDF4J value

Throws:

IllegalArgumentException - if the value is not a BNode, Literal or IRI

asDataset

public RDF4JDataset asDataset(org.eclipse.rdf4j.repository.Repository repository,
                              RDF4J.Option... options)

Adapt an RDF4J Repository as a Commons RDF Dataset.

Changes to the dataset are reflected in the repository, and vice versa.

Note: Some operations on the RDF4JDataset requires the use of try-with-resources to close underlying RepositoryConnections, including RDF4JDataset.iterate(), RDF4JDataset.stream() and RDF4JDataset.getGraphNames().

Parameters:

repository - RDF4J Repository to connect to.

options - Zero or more RDF4J.Option

Returns:

A Dataset backed by the RDF4J repository.

asGraph

public RDF4JGraph asGraph(org.eclipse.rdf4j.model.Model model)

Adapt an RDF4J Model as a Commons RDF Graph.

Changes to the graph are reflected in the model, and vice versa.

Parameters:

model - RDF4J Model to adapt.

Returns:

Adapted Graph.

asGraph

public RDF4JGraph asGraph(org.eclipse.rdf4j.repository.Repository repository,
                          RDF4J.Option... options)

Adapt an RDF4J Repository as a Commons RDF Graph.

The graph will only include triples in the default graph (equivalent to context new Resource[0]{null}) in RDF4J).

Changes to the graph are reflected in the repository, and vice versa.

Note: Some operations on the RDF4JGraph requires the use of try-with-resources to close underlying RepositoryConnections, including RDF4JGraph.iterate() and RDF4JGraph.stream().

Parameters:

repository - RDF4J Repository to connect to.

options - Zero or more RDF4J.Option

Returns:

A Graph backed by the RDF4J repository.

asGraphUnion

public RDF4JGraph asGraphUnion(org.eclipse.rdf4j.repository.Repository repository,
                               RDF4J.Option... options)

Adapt an RDF4J Repository as a Commons RDF Graph.

The graph will include triples in any contexts (e.g. the union graph).

Changes to the graph are reflected in the repository, and vice versa.

Parameters:

repository - RDF4J Repository to connect to.

options - Zero or more RDF4J.Option

Returns:

A union Graph backed by the RDF4J repository.

asGraph

public RDF4JGraph asGraph(org.eclipse.rdf4j.repository.Repository repository,
                          Set<? extends BlankNodeOrIRI> contexts,
                          RDF4J.Option... option)

Adapt an RDF4J Repository as a Commons RDF Graph.

The graph will include triples in the specified contexts.

Changes to the graph are reflected in the repository, and vice versa. Triples added/removed to the graph are reflected in all the specified contexts.

Note: Some operations on the RDF4JGraph requires the use of try-with-resources to close underlying RepositoryConnections, including RDF4JGraph.iterate() and RDF4JGraph.stream().

Parameters:

repository - RDF4J Repository to connect to.

contexts - A Set of BlankNodeOrIRI specifying the graph names to use as a context. The set may include the value null to indicate the default graph. The empty set indicates any context, e.g. the union graph.

option - Zero or more RDF4J.Options

Returns:

A Graph backed by the RDF4J repository.

asStatement

public org.eclipse.rdf4j.model.Statement asStatement(TripleLike tripleLike)

Adapt a Commons RDF Triple or Quad as a RDF4J Statement.

If the tripleLike argument is an RDF4JTriple or a RDF4JQuad, then its RDF4JTripleLike.asStatement() is returned as-is. Note that this means that a RDF4JTriple would preserve its Statement.getContext(), and that any BlankNodes would be deemed equivalent in RDF4J if they have the same BNode.getID().

Parameters:

tripleLike - A Triple or Quad to adapt

Returns:

A corresponding Statement

asTriple

public RDF4JTriple asTriple(org.eclipse.rdf4j.model.Statement statement)

Adapt a RDF4J Statement as a Commons RDF Triple.

For the purpose of BlankNode equivalence, this method will use an internal salt UUID that is unique per instance of RDF4J.

NOTE: If combining RDF4J statements from multiple repositories or models, then their BNodes may have the same BNode.getID(), which with this method would become equivalent according to BlankNode.equals(Object) and BlankNode.uniqueReference(), unless a separate RDF4J instance is used per RDF4J repository/model.

Parameters:

statement - The RDF4J Statement to adapt.

Returns:

A RDF4JTriple that is equivalent to the statement

asValue

public org.eclipse.rdf4j.model.Value asValue(RDFTerm term)

Adapt a Commons RDF RDFTerm as a RDF4J Value.

The value will be of the same kind as the term, e.g. a BlankNode is converted to a BNode, a IRI is converted to a IRI and a Literal is converted to a Literal.

If the provided RDFTerm is null, then the returned value is null.

If the provided term is an instance of RDF4JTerm, then the RDF4JTerm.asValue() is returned without any conversion. Note that this could mean that a Value from a different kind of ValueFactory could be returned.

Parameters:

term - RDFTerm to adapt to RDF4J Value

Returns:

Adapted RDF4J Value

createBlankNode

public RDF4JBlankNode createBlankNode()

Description copied from interface: RDF

Create a new blank node.

The returned blank node MUST NOT be equal to any existing BlankNode instances according to BlankNode.equals(Object).

Specified by:

createBlankNode in interface RDF

Returns:

A new, unique BlankNode

createBlankNode

public RDF4JBlankNode createBlankNode(String name)

Description copied from interface: RDF

Create a blank node based on the given name.

All BlankNodes created with the given name on a particular instance of RDF MUST be equivalent according to BlankNode.equals(Object),

The returned BlankNode MUST NOT be equal to BlankNode instances returned for any other name or those returned from RDF.createBlankNode().

The returned BlankNode SHOULD NOT be equivalent to any BlankNodes created on a different RDF instance, e.g. different instances of RDF should produce different blank nodes for the same name unless they purposely are intending to create equivalent BlankNode instances (e.g. a reinstated Serializable factory).

Specified by:

createBlankNode in interface RDF

Parameters:

name - A non-empty, non-null, String that is unique to this blank node in the context of this RDF.

Returns:

A BlankNode for the given name

createDataset

public RDF4JDataset createDataset()

Create a new dataset. It is undefined if the dataset will be persisted by any underlying storage mechanism.

Note: Some operations on the RDF4JDataset requires the use of try-with-resources to close underlying RepositoryConnections, including RDF4JDataset.iterate(), RDF4JDataset.stream() and RDF4JDataset.getGraphNames().

Specified by:

createDataset in interface RDF

Returns:

A new Dataset

createGraph

public RDF4JGraph createGraph()

Description copied from interface: RDF

Create a new graph. It is undefined if the graph will be persisted by any underlying storage mechanism.

Specified by:

createGraph in interface RDF

Returns:

A new Graph

createIRI

public RDF4JIRI createIRI(String iri)
                   throws IllegalArgumentException

Description copied from interface: RDF

Create an IRI from a (possibly escaped) String. The provided iri string MUST be valid according to the W3C RDF-1.1 IRI definition.

Specified by:

createIRI in interface RDF

Parameters:

iri - Internationalized Resource Identifier

Returns:

A new IRI

Throws:

IllegalArgumentException - If the provided string is not acceptable, e.g. does not conform to the RFC3987 syntax.

createLiteral

public RDF4JLiteral createLiteral(String lexicalForm)
                           throws IllegalArgumentException

Description copied from interface: RDF

Create a simple literal. The provided lexical form should not be escaped in any sense, e.g. should not include "quotes" unless those are part of the literal value. The returned Literal MUST have a Literal.getLexicalForm() that is equal to the provided lexical form, MUST NOT have a Literal.getLanguageTag() present, and SHOULD return a Literal.getDatatype() that is equal to the IRI http://www.w3.org/2001/XMLSchema#string.

Specified by:

createLiteral in interface RDF

Parameters:

lexicalForm - The literal value in plain text

Returns:

The created Literal

Throws:

IllegalArgumentException - If the provided lexicalForm is not acceptable, e.g. because it is too large for an underlying storage.

createLiteral

public Literal createLiteral(String lexicalForm,
                             IRI dataType)
                      throws IllegalArgumentException

Description copied from interface: RDF

Create a literal with the specified data type. The provided lexical form should not be escaped in any sense, e.g. should not include "quotes" unless those are part of the literal value. It is RECOMMENDED that the provided dataType is one of the RDF-compatible XSD types. The provided lexical form SHOULD be in the lexical space of the provided dataType. The returned Literal SHOULD have a Literal.getLexicalForm() that is equal to the provided lexicalForm, MUST NOT have a Literal.getLanguageTag() present, and MUST return a Literal.getDatatype() that is equivalent to the provided dataType IRI.

Specified by:

createLiteral in interface RDF

Parameters:

lexicalForm - The literal value

dataType - The data type IRI for the literal value, e.g. http://www.w3.org/2001/XMLSchema#integer

Returns:

The created Literal

Throws:

IllegalArgumentException - If any of the provided arguments are not acceptable, e.g. because the provided dataType is not permitted.

createLiteral

public Literal createLiteral(String lexicalForm,
                             String languageTag)
                      throws IllegalArgumentException

Description copied from interface: RDF

Create a language-tagged literal. The provided lexical form should not be escaped in any sense, e.g. should not include "quotes" unless those are part of the literal value. The provided language tag MUST be valid according to BCP47, e.g. en. The provided language tag MAY be converted to lower case. The returned Literal SHOULD have a Literal.getLexicalForm() which is equal to the provided lexicalForm, MUST return a Literal.getDatatype() that is equal to the IRI http://www.w3.org/1999/02/22-rdf-syntax-ns#langString, and MUST have a Literal.getLanguageTag() present which SHOULD be equal to the provided language tag (compared as String.toLowerCase(Locale) using Locale.ENGLISH).

Specified by:

createLiteral in interface RDF

Parameters:

lexicalForm - The literal value

languageTag - The non-empty language tag as defined by BCP47

Returns:

The created Literal

Throws:

IllegalArgumentException - If the provided values are not acceptable, e.g. because the languageTag was syntactically invalid.

createTriple

public RDF4JTriple createTriple(BlankNodeOrIRI subject,
                                IRI predicate,
                                RDFTerm object)
                         throws IllegalArgumentException

Description copied from interface: RDF

Create a triple. The returned Triple SHOULD have a Triple.getSubject() that is equal to the provided subject, a Triple.getPredicate() that is equal to the provided predicate, and a Triple.getObject() that is equal to the provided object.

Specified by:

createTriple in interface RDF

Parameters:

subject - The IRI or BlankNode that is the subject of the triple

predicate - The IRI that is the predicate of the triple

object - The IRI, BlankNode or Literal that is the object of the triple

Returns:

The created Triple

Throws:

IllegalArgumentException - If any of the provided arguments are not acceptable, e.g. because a Literal has a lexicalForm that is too large for an underlying storage.

createQuad

public Quad createQuad(BlankNodeOrIRI graphName,
                       BlankNodeOrIRI subject,
                       IRI predicate,
                       RDFTerm object)
                throws IllegalArgumentException

Description copied from interface: RDF

Create a quad.

The returned Quad SHOULD have a Quad.getGraphName() that is equal to the provided graphName, a Quad.getSubject() that is equal to the provided subject, a Quad.getPredicate() that is equal to the provided predicate, and a Quad.getObject() that is equal to the provided object.

Specified by:

createQuad in interface RDF

Parameters:

graphName - The IRI or BlankNode that this quad belongs to, or null for the public graph

subject - The IRI or BlankNode that is the subject of the quad

predicate - The IRI that is the predicate of the quad

object - The IRI, BlankNode or Literal that is the object of the quad

Returns:

The created Quad

Throws:

IllegalArgumentException - If any of the provided arguments are not acceptable, e.g. because a Literal has a lexicalForm that is too large for an underlying storage.

getValueFactory

public org.eclipse.rdf4j.model.ValueFactory getValueFactory()