Interface FederatedService
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- All Known Implementing Classes:
RepositoryFederatedService,RepositoryFederatedService,SPARQLFederatedService,SPARQLFederatedService,TupleFunctionFederatedService
public interface FederatedServiceFederatedService to allow for customized evaluation of SERVICE expression. By defaultSPARQLFederatedServiceis used.- Author:
- Andreas Schwarte, James Leigh
- See Also:
SPARQLFederatedService
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Method Summary
All Methods Instance Methods Abstract Methods Modifier and Type Method Description booleanask(Service service, BindingSet bindings, String baseUri)Evaluate the provided SPARQL ASK query at this federated service.CloseableIteration<BindingSet,QueryEvaluationException>evaluate(Service service, CloseableIteration<BindingSet,QueryEvaluationException> bindings, String baseUri)Evaluate the provided SPARQL query at this federated service, possibilities for vectored evaluation.voidinitialize()Method to perform any initializations, invoked after construction.booleanisInitialized()Method to check ifinitialize()had been called.CloseableIteration<BindingSet,QueryEvaluationException>select(Service service, Set<String> projectionVars, BindingSet bindings, String baseUri)Evaluate the provided SPARQL query at this federated service.voidshutdown()Method to perform any shutDown code, invoked at unregistering.
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Method Detail
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ask
boolean ask(Service service, BindingSet bindings, String baseUri) throws QueryEvaluationException
Evaluate the provided SPARQL ASK query at this federated service.
Expected behavior: evaluate boolean query using the bindings as constraints
- Parameters:
service- the reference to the service node, contains additional meta information (vars, prefixes)bindings- the bindings serving as additional constraintsbaseUri-- Returns:
trueif at least one result exists- Throws:
QueryEvaluationException- If there was an exception generated while evaluating the query.
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select
CloseableIteration<BindingSet,QueryEvaluationException> select(Service service, Set<String> projectionVars, BindingSet bindings, String baseUri) throws QueryEvaluationException
Evaluate the provided SPARQL query at this federated service.
Important: The original bindings need to be inserted into the result.
Expected behavior: evaluate the given SPARQL query using the bindings as constraints
- Parameters:
service- the reference to the service node, contains additional meta information (vars, prefixes)projectionVars- The variables with unknown value that should be projected from this evaluationbindings- the bindings serving as additional constraintsbaseUri-- Returns:
- an iteration over the results of the query
- Throws:
QueryEvaluationException- If there was an exception generated while evaluating the query.
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evaluate
CloseableIteration<BindingSet,QueryEvaluationException> evaluate(Service service, CloseableIteration<BindingSet,QueryEvaluationException> bindings, String baseUri) throws QueryEvaluationException
Evaluate the provided SPARQL query at this federated service, possibilities for vectored evaluation.Contracts:
- The original bindings need to be inserted into the result
- SILENT service must be dealt with in the method
Compare
SPARQLFederatedServicefor a reference implementation- Parameters:
service- the reference to the service node, contains information to construct the querybindings- the bindings serving as additional constraints (for vectored evaluation)baseUri- the baseUri- Returns:
- the result of evaluating the query using bindings as constraints, the original bindings need to be inserted into the results!
- Throws:
QueryEvaluationException- If there was an exception generated while evaluating the query.
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isInitialized
boolean isInitialized()
Method to check ifinitialize()had been called.
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initialize
void initialize() throws QueryEvaluationExceptionMethod to perform any initializations, invoked after construction.- Throws:
QueryEvaluationException- If there was an exception generated while initializing the service.
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shutdown
void shutdown() throws QueryEvaluationExceptionMethod to perform any shutDown code, invoked at unregistering.- Throws:
QueryEvaluationException- If there was an exception generated while shutting down the service.
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