Package 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 Details

    • log

      private org.slf4j.Logger log

    • qef

      public org.aksw.jena_sparql_api.core.QueryExecutionFactory qef

    • timeToLive

      private long timeToLive

  • Constructor Details

  • Method Details

    • 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)