bif:contain error occurs when try to query dbpedia through my java program

问题

the code is for querying dbpedia from java program and then displaying the result in html page

package jenaamem;

import com.hp.hpl.jena.query.Query;
import com.hp.hpl.jena.query.QueryExecution;
import com.hp.hpl.jena.query.QueryExecutionFactory;
import com.hp.hpl.jena.query.QueryFactory;
import com.hp.hpl.jena.query.ResultSet;
import com.hp.hpl.jena.query.ResultSetFormatter;
import com.hp.hpl.jena.sparql.engine.http.QueryEngineHTTP;

public class db2
{
static public void main(String...argv)
{
    try {
        String queryStr = "SELECT * WHERE{ ?s ?p ?o . ?o bif:contains' barack and obama and america' OPTION (score ?sc) } ORDER BY DESC (?sc) LIMIT 10 ";
        Query query = QueryFactory.create(queryStr);

        // Remote execution.
        QueryExecution qexec =   QueryExecutionFactory.sparqlService("http://dbpedia.org/sparql", query);
        // Set the DBpedia specific timeout.
        ((QueryEngineHTTP)qexec).addParam("timeout", "10000") ;

        // Execute.
        ResultSet rs = qexec.execSelect();
        ResultSetFormatter.out(System.out, rs, query);
        qexec.close();
    } catch (Exception e) {
    }


}

}

here the problem i am facing in this code is that bif:contains is showing error, i even tried then also my problem continues.

回答1:

bif:contains is a prefixed name but you haven't defined a prefix for it so the ARQ parser throws an error as it should

Unfortunately bif:contains is a Virtuoso specific extension and doesn't actually have any associated prefix so you can't define it. However you can enclose it in < and > so that ARQ treats it like a URI and Virtuoso will still understand it i.e. use <bif:contains> in your query instead.

来源：https://stackoverflow.com/questions/15876916/bifcontain-error-occurs-when-try-to-query-dbpedia-through-my-java-program

标签

java

sparql

dbpedia