Java 遇到Sparql词法错误：“”（32），在“not”之后

使用Jena创建sparql查询时出现词法错误。 下面是我的源代码。错误是 com.hp.hpl.jena.query.QueryParseException:第5行第92列出现词法错误。遇到：32，在：not之后

    package mas;
    import agent.core.onto.Ontology;
    import com.hp.hpl.jena.ontology.OntDocumentManager;
    import com.hp.hpl.jena.ontology.OntModel;
    import com.hp.hpl.jena.ontology.OntModelSpec;
    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.QuerySolution;
    import com.hp.hpl.jena.query.ResultSet;
    import com.hp.hpl.jena.rdf.model.Model;
    import com.hp.hpl.jena.rdf.model.ModelFactory;
    import com.hp.hpl.jena.rdf.model.ModelMaker;
    import java.io.FileInputStream;

    /**
    *
    * @author Naveed Khan
    */
    public class NewClass {

      public static void main(String arg[])
       {
        NewClass obj=new NewClass(); 
        String PREFIX="PREFIX seo:            <http://www.seontology.org/test/specificOnto.owl#> 
       PREFIX rdf: <http://www.w3.org/1999/02/22-rdf-syntax-ns#>
       PREFIX rdfs: <http://www.w3.org/2000/01/rdf-schema#> "
        Model m = obj.getModel();
        String querystr=PREFIX + 
                " \n SELECT  ?individualaff ?uc "
                        + "WHERE { "
                        + "?individualaff  seo:Requirements_Content ?c. "
                        + "filter not exists {?individualaff seo:hasUsecase ?uc } "
                        + "}";
        try 
        {
            Query query = QueryFactory.create(querystr) ;
            QueryExecution qexec = QueryExecutionFactory.create(query, m) ;
            ResultSet results = qexec.execSelect() ;
            QuerySolution soln = results.nextSolution() ;
        }catch(Exception ex) { 
         ex.printStackTrace(); }



}
private OntModel getModel()
{
    OntModel model = null;
    if (model == null) {

    model = ModelFactory.createOntologyModel(OntModelSpec.OWL_MEM, null);
    try {

        model.read(new FileInputStream(agent.core.onto.Config.SOURCE_FILE), Ontology.BASE);

    } catch (Exception e) {
        System.out.println("Loading Model failed:"+ e);
    }
  } 
        if (model != null)
          return model;
        else
          return null;
        }
        }

The error says
com.hp.hpl.jena.query.QueryParseException: Lexical error at line 5, column 92.     Encountered: " " (32), after : "not".

---

实际查询：选择？fr？uc，其中{？fr seo:Requirements_Content？c.过滤器不存在{？fr seo:hausecase？uc}对我有效。您使用的是哪种版本的jena？谢谢，我通过获取最新版本的jenaget和最新版本的Jena2.0.13解决了这个问题，并且对于FILTER？location=dbpedia:葡萄牙或？location=dbpedia:Spain-第1行第261列的词法错误有相同的错误。遇到：32，之后：或