org.openrdf.query.algebra.evaluation.federation

Class RepositoryFederatedService

java.lang.Object

org.openrdf.query.algebra.evaluation.federation.RepositoryFederatedService

All Implemented Interfaces:

FederatedService

Direct Known Subclasses:

SPARQLFederatedService

public class RepositoryFederatedService
extends Object
implements FederatedService

Federated Service wrapping the Repository to communicate with a SPARQL endpoint.

Author:

Andreas Schwarte

Field Summary

Fields

Modifier and Type	Field and Description
protected RepositoryConnection	conn
protected Repository	rep
protected boolean	shutDown

Constructor Summary

Constructors

Constructor and Description
RepositoryFederatedService(Repository repo)
RepositoryFederatedService(Repository repo, boolean shutDown)

Method Summary

Modifier and Type	Method and Description
protected static StringBuilder	appendLiteral(StringBuilder sb, Literal lit) Append the literal to the stringbuilder: "myLiteral"^^
protected static StringBuilder	appendURI(StringBuilder sb, URI uri) Append the uri to the stringbuilder, i.e.
protected StringBuilder	appendValueAsString(StringBuilder sb, Value value)
boolean	ask(Service service, BindingSet bindings, String baseUri) Evaluate the provided sparqlQueryString at the initialized Repository of this FederatedService.
CloseableIteration<BindingSet,QueryEvaluationException>	evaluate(Service service, CloseableIteration<BindingSet,QueryEvaluationException> bindings, String baseUri)
protected CloseableIteration<BindingSet,QueryEvaluationException>	evaluateInternal(Service service, CloseableIteration<BindingSet,QueryEvaluationException> bindings, String baseUri) Evaluate the SPARQL query that can be constructed from the SERVICE node at the initialized Repository of this FederatedService.
protected RepositoryConnection	getConnection()
void	initialize()
boolean	isInitialized()
CloseableIteration<BindingSet,QueryEvaluationException>	select(Service service, Set<String> projectionVars, BindingSet bindings, String baseUri) Evaluate the provided sparqlQueryString at the initialized Repository of this FederatedService.
void	shutdown()

Methods inherited from class java.lang.Object

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

Field Detail

rep

protected final Repository rep

shutDown

protected boolean shutDown

conn

protected RepositoryConnection conn

Constructor Detail

RepositoryFederatedService

public RepositoryFederatedService(Repository repo)

Parameters:

repo - the repository to be used

RepositoryFederatedService

public RepositoryFederatedService(Repository repo,
                                  boolean shutDown)

Parameters:

repo - the repository to be used

shutDown - a flag indicating whether the repository shall be closed in shutdown()

Method Detail

select

public CloseableIteration<BindingSet,QueryEvaluationException> select(Service service,
                                                                      Set<String> projectionVars,
                                                                      BindingSet bindings,
                                                                      String baseUri)
                                                               throws QueryEvaluationException

Evaluate the provided sparqlQueryString at the initialized Repository of this FederatedService. Insert bindings into SELECT query and evaluate

Specified by:

select in interface FederatedService

Throws:

QueryEvaluationException

ask

public boolean ask(Service service,
                   BindingSet bindings,
                   String baseUri)
            throws QueryEvaluationException

Evaluate the provided sparqlQueryString at the initialized Repository of this FederatedService. Insert bindings, send ask query and return final result

Specified by:

ask in interface FederatedService

Throws:

QueryEvaluationException

evaluate

public CloseableIteration<BindingSet,QueryEvaluationException> evaluate(Service service,
                                                                        CloseableIteration<BindingSet,QueryEvaluationException> bindings,
                                                                        String baseUri)
                                                                 throws QueryEvaluationException

Specified by:

evaluate in interface FederatedService

Throws:

QueryEvaluationException

evaluateInternal

protected CloseableIteration<BindingSet,QueryEvaluationException> evaluateInternal(Service service,
                                                                                   CloseableIteration<BindingSet,QueryEvaluationException> bindings,
                                                                                   String baseUri)
                                                                            throws QueryEvaluationException

Evaluate the SPARQL query that can be constructed from the SERVICE node at the initialized Repository of this FederatedService. Use specified bindings as constraints to the query. Try to evaluate using BINDINGS clause, if this yields an exception fall back to the naive implementation. This method deals with SILENT SERVICEs.

Throws:

QueryEvaluationException

initialize

public void initialize()
                throws QueryEvaluationException

Specified by:

initialize in interface FederatedService

Throws:

QueryEvaluationException

isInitialized

public boolean isInitialized()

Specified by:

isInitialized in interface FederatedService

shutdown

public void shutdown()
              throws QueryEvaluationException

Specified by:

shutdown in interface FederatedService

Throws:

QueryEvaluationException

getConnection

protected RepositoryConnection getConnection()
                                      throws RepositoryException

Throws:

RepositoryException

appendValueAsString

protected StringBuilder appendValueAsString(StringBuilder sb,
                                            Value value)

appendURI

protected static StringBuilder appendURI(StringBuilder sb,
                                         URI uri)

Append the uri to the stringbuilder, i.e. .

Parameters:

sb -

uri -

Returns:

the StringBuilder, for convenience

appendLiteral

protected static StringBuilder appendLiteral(StringBuilder sb,
                                             Literal lit)

Append the literal to the stringbuilder: "myLiteral"^^

Parameters:

sb -

lit -

Returns:

the StringBuilder, for convenience