创建猫头鹰文件时出错

Question

I want to create ontology whit this code:

public static void main(String[] args) throws FileNotFoundException {
    // TODO code application logic here
    OntModel my_model= ModelFactory.createOntologyModel();
    ObjectProperty op = my_model.createObjectProperty("b");
    OntClass my_class = my_model.createClass("student");
    DatatypeProperty  dtp = my_model.createDatatypeProperty("name");
    dtp.addDomain(my_class);
    FileOutputStream univer= new FileOutputStream("c:/uni.owl");
    my_model.write(univer,"RDF/XML-ABBREV","ns");

} 

But it gives this error:

java.lang.NoClassDefFoundError: com/hp/hpl/jena/rdf/model/Resource
Caused by: java.lang.ClassNotFoundException: com.hp.hpl.jena.rdf.model.Resource
        at java.net.URLClassLoader$1.run(URLClassLoader.java:202)
        at java.security.AccessController.doPrivileged(Native Method)
        at java.net.URLClassLoader.findClass(URLClassLoader.java:190)
        at java.lang.ClassLoader.loadClass(ClassLoader.java:307)
        at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:301)
        at java.lang.ClassLoader.loadClass(ClassLoader.java:248)
Could not find the main class: javaapplication6.Main.  Program will exit.
Exception in thread "main" Java Result: 1

I cannot understand what is the problem.Thanks for any Help.

Answer 1

NoClassDefFoundError means the Java Virtual Machine or a ClassLoader instance tries to load in the definition of a class (as part of a normal method call or as part of creating a new instance using the new expression) and no definition of the class could be found.

Try to download Apache Jena library from here and put it in your classpath