org.aksw.qa.commons.sparql

Class SPARQL

java.lang.Object

org.aksw.qa.commons.sparql.SPARQL

Direct Known Subclasses:

ThreadedSPARQL

public class SPARQL
extends Object

Executes sparql queries.

Field Summary

Fields

Modifier and Type	Field and Description
private org.slf4j.Logger	log
org.aksw.jena_sparql_api.core.QueryExecutionFactory	qef
private long	timeToLive

Constructor Summary

Constructors

Constructor and Description
SPARQL() SPARQLEndpoints.DBPEDIA_ORG as endpoint used.
SPARQL(String endpoint)

Method Summary

Modifier and Type	Method and Description
private static void	closeExecFactory(org.aksw.jena_sparql_api.core.QueryExecutionFactory qef)
static Boolean	executeAsk(String query, String endpoint) Executes an ask query for the given endpoint and query.
static Results	executeSelect(String query, String endpoint) Executes a select query for the given endpoint and query.
static Set<String>	extractAnswerStrings(Set<org.apache.jena.rdf.model.RDFNode> answers) For use with sparql(String) Extracts answer strings.
long	getCacheTimeToLive()
static boolean	isEndpointAlive(String endpoint) Checks if the given endpoint is alive.
static boolean	isValidSparqlQuery(String sparql) Tries to parse query with apache.jena .
void	setCacheTimeToLive(long timeToLive)
Set<org.apache.jena.rdf.model.RDFNode>	sparql(String query) Fire a sparql query against endpoint defined in constructor.

Methods inherited from class java.lang.Object

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

Field Detail

log

private org.slf4j.Logger log

qef

public org.aksw.jena_sparql_api.core.QueryExecutionFactory qef

timeToLive

private long timeToLive

Constructor Detail

SPARQL

public SPARQL()

SPARQLEndpoints.DBPEDIA_ORG as endpoint used.

SPARQL

public SPARQL(String endpoint)

Parameters:

endpoint - - A sparql endpoint, e.g. SPARQLEndpoints.DBPEDIA_ORG

Method Detail

sparql

public Set<org.apache.jena.rdf.model.RDFNode> sparql(String query)

Fire a sparql query against endpoint defined in constructor.

NOTE: This will block. To set a maximum execution time, use ThreadedSPARQL

For string representation of answers, see extractAnswerStrings(Set)

Parameters:

query - - a sparql query

Returns:

extractAnswerStrings

public static Set<String> extractAnswerStrings(Set<org.apache.jena.rdf.model.RDFNode> answers)

For use with sparql(String) Extracts answer strings. Can be directly set as golden answers in an IQuestion.

Parameters:

answers -

Returns:

executeSelect

public static Results executeSelect(String query,
                                    String endpoint)

Executes a select query for the given endpoint and query. Returns the answer as an Results object.

Parameters:

query -

endpoint -

Returns:

executeAsk

public static Boolean executeAsk(String query,
                                 String endpoint)

Executes an ask query for the given endpoint and query.

Parameters:

query -

endpoint -

Returns:

getCacheTimeToLive

public long getCacheTimeToLive()

Returns:

- The time to live of frontendCache

setCacheTimeToLive

public void setCacheTimeToLive(long timeToLive)

isValidSparqlQuery

public static boolean isValidSparqlQuery(String sparql)

Tries to parse query with apache.jena . If fails, returns false.

Parameters:

sparql -

Returns:

isEndpointAlive

public static boolean isEndpointAlive(String endpoint)

Checks if the given endpoint is alive. If fails, returns false.

Parameters:

endpoint -

Returns:

closeExecFactory

private static void closeExecFactory(org.aksw.jena_sparql_api.core.QueryExecutionFactory qef)