com.franz.agraph.repository

Class AGValueFactory

java.lang.Object

org.eclipse.rdf4j.model.impl.AbstractValueFactory

org.eclipse.rdf4j.model.impl.SimpleValueFactory

com.franz.agraph.repository.AGValueFactory

All Implemented Interfaces:

ValueFactory

public class AGValueFactory
extends SimpleValueFactory

Implements the Sesame ValueFactory interface for AllegroGraph.

Field Summary

Fields

Modifier and Type	Field and Description
String	PREFIX_FOR_EXTERNAL_BNODES

Constructor Summary

Constructors

Constructor and Description
AGValueFactory(AGRepository repository)
AGValueFactory(AGRepository repository, AGRepositoryConnection conn)

Method Summary

Modifier and Type	Method and Description
Resource	asResource(Node node)
IRI	asURI(Node node)
Value	asValue(Node node) Creates an OpenRDF Value from a concrete Jena Node.
BNode	createBNode() Returns a new blank node.
BNode	createBNode(String nodeID) Returns a new blank node with the given id.
IRI	generateURI(String registeredEncodableNamespace) Returns a unique URI within the specified encodable namespace.
IRI[]	generateURIs(String namespace, int amount) Returns unique URIs within the specified encodable namespace.
String[]	getBlankNodeIds() Returns the array of fetched blank node ids
int	getBlankNodesPerRequest() Gets the number of blank nodes fetched per request.
AGHTTPClient	getHTTPClient()
AGRepository	getRepository()
boolean	isAGBlankNodeId(String id) Returns true iff id looks like an AG blank node id.
boolean	isURIForExternalBlankNode(Value v)
void	setBlankNodesPerRequest(int amount) Sets the number of blank nodes to fetch per request.

Methods inherited from class org.eclipse.rdf4j.model.impl.SimpleValueFactory

getInstance

Methods inherited from class org.eclipse.rdf4j.model.impl.AbstractValueFactory

createIRI, createIRI, createLiteral, createLiteral, createLiteral, createLiteral, createLiteral, createLiteral, createLiteral, createLiteral, createLiteral, createLiteral, createLiteral, createLiteral, createLiteral, createLiteral, createStatement, createStatement

Methods inherited from class java.lang.Object

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

Methods inherited from interface org.eclipse.rdf4j.model.ValueFactory

createLiteral, createStatement, createStatement, createURI, createURI

Field Detail

PREFIX_FOR_EXTERNAL_BNODES

public String PREFIX_FOR_EXTERNAL_BNODES

Constructor Detail

AGValueFactory

public AGValueFactory(AGRepository repository)

AGValueFactory

public AGValueFactory(AGRepository repository,
                      AGRepositoryConnection conn)

Method Detail

getRepository

public AGRepository getRepository()

getHTTPClient

public AGHTTPClient getHTTPClient()

getBlankNodesPerRequest

public int getBlankNodesPerRequest()

Gets the number of blank nodes fetched per request.

Returns:

int the number of blank nodes fetched per request

setBlankNodesPerRequest

public void setBlankNodesPerRequest(int amount)

Sets the number of blank nodes to fetch per request.

This can be used to control the number and frequency of HTTP requests made when automatically obtaining new sets of blank node ids from the server.

Defaults to the value of System property com.franz.agraph.repository.blankNodesPerRequest or to 100 if that property has not been set.

Parameters:

amount - a positive integer

getBlankNodeIds

public String[] getBlankNodeIds()

Returns the array of fetched blank node ids

Primarily for testing purposes, not for use in apps.

Returns:

the array of fetched blank node ids

createBNode

public BNode createBNode(String nodeID)

Returns a new blank node with the given id.

Consider using createBNode() instead to get an AG-allocated id, it is safer (avoids unintended blank node conflicts) and can be stored more efficiently.

If id is null or empty, returns a unique BNode with AG-allocated id; otherwise, returns a BNode with the given (a.k.a. "external") id (careful to avoid blank node conflicts). See the javadoc for allowing external blank nodes for more discussion.

Specified by:

createBNode in interface ValueFactory

Overrides:

createBNode in class AbstractValueFactory

See Also:

AGHttpRepoClient.setAllowExternalBlankNodeIds(boolean), AGRepositoryConnection.prepareHttpRepoClient()

createBNode

public BNode createBNode()

Returns a new blank node.

If this value factory is for an AGRepository, returns a new BNode with an AG-allocated id; otherwise, returns a new BNode with an "external" id (using ValueFactoryImpl). See also the javadoc for allowing external blank nodes for more discussion.

Specified by:

createBNode in interface ValueFactory

Overrides:

createBNode in class AbstractValueFactory

See Also:

AGHttpRepoClient.setAllowExternalBlankNodeIds(boolean), AGRepositoryConnection.prepareHttpRepoClient()

asValue

public Value asValue(Node node)

Creates an OpenRDF Value from a concrete Jena Node.

Parameters:

node - a concrete Jena node

Returns:

the corresponding Value

isAGBlankNodeId

public boolean isAGBlankNodeId(String id)

Returns true iff id looks like an AG blank node id.

AG blank node ids currently have the following form:

b[store ID in hex]x[blank node number].

There is nothing sacrosanct about this but it is unlikely to change.

Parameters:

id - the string to be tested

Returns:

true iff id looks like an AG blank node id

isURIForExternalBlankNode

public boolean isURIForExternalBlankNode(Value v)

asResource

public Resource asResource(Node node)

asURI

public IRI asURI(Node node)

generateURIs

public IRI[] generateURIs(String namespace,
                          int amount)
                   throws RepositoryException

Returns unique URIs within the specified encodable namespace.

The generated URIs will conform to the format that was specified when the encodable namespace was registered, and are guaranteed to be unique for this namespace generator. Note that this does not prevent other parties from independently using URIs that involve this namespace, however.

If amount cannot be generated, up to amount URIs will be returned, or an exception will be thrown if none are available.

Parameters:

namespace - encodable namespace from which the URIs will be generated

amount - the number of URIs to generate

Returns:

a unique URI within the specified namespace.

Throws:

RepositoryException - if there is an error with this request

See Also:

AGRepositoryConnection.registerEncodableNamespace(String, String), generateURI(String)

generateURI

public IRI generateURI(String registeredEncodableNamespace)
                throws RepositoryException

Returns a unique URI within the specified encodable namespace.

The generated URI will conform to the format that was specified when the encodable namespace was registered, and is guaranteed to be unique for this namespace generator. Note that this does not prevent other parties from independently using URIs that involve this namespace, however.

Parameters:

registeredEncodableNamespace - encodable namespace from which the URI will be generated

Returns:

a unique URI within the specified namespace.

Throws:

RepositoryException - if there is an error with this request

See Also:

AGRepositoryConnection.registerEncodableNamespace(String, String), generateURIs(String, int)