String queryPrefix = "" +
                "PREFIX dbr: <http://dbpedia.org/resource/>\n" +
                "PREFIX dbo: <http://dbpedia.org/ontology/>\n" +
                "SELECT DISTINCT ?class\n" +
                "WHERE {\n" +
                "dbr:";
        String querySuffix = " a ?class.\n" +
                "FILTER regex(str(?class), \"/ontology\")\n" +
                "}";

        ParameterizedSparqlString qs = new ParameterizedSparqlString(queryPrefix + target + querySuffix);

        QueryExecution exec = QueryExecutionFactory.sparqlService("http://dbpedia.org/sparql", qs.asQuery());