如何纠正jena中的错误

Question

我在netbeans中添加了jena api。运行以下代码后，它显示此行中的错误 OntModel model = ModelFactory.createOntologyModel（OntModelSpec.OWL_MEM）; csr.owl是我的本体文件名

我的代码：

public class JavaApplication1 {
  private static Object ModelFactory;
  private static Object OntModelSpec;

  /**
  * @param args the command line arguments
  */
   public static void main(String[] args) {
    // TODO code application logic here
    String filename = "csr.owl";
    try
    {
        File file = new File(filename);
        FileReader reader= new FileReader(file);
        OntModel model =        ModelFactory.createOntologyModel(OntModelSpec.OWL_MEM);
        model.read(reader,null);
        model.write(System.out,"RDF/XML-ABBREV");
     }
     catch (Exception e)
    {
        e.printStackTrace();
    }
    }
}