Jena ontology API

Question

I'm new to Jena and Protégé. I did some stuff with these. I have some problems:

1. Do I need to use SPARQL query to get the ontology classes, subclasses, properties, and values, or can I do it with OWL-api? Can you show me how?
2. How do I get the data property values?
3. How do I load the ontology that is defined in my local machine and access the classes?

Answer 1

The Jena Ontology API is great for getting individual classes, properties, and their details and relationships.

SPARQL queries are great for querying a large number of instances and filter out only the bits of information (including their property values) that you need.

For your other questions, reading a bit of the documentation might help! The answers are in here:

• Intro to RDF and Jena
• Ontology API
• I/O Quick Intro

Answer 2

GitHub上的jena-examples项目演示了API的一些用例 。

Answer 3

Yup jena-fuseki server can be used to query ontology classes,subclasses,properties and values. Download apache jena-fuseki server Next we import this ontology to Apache's Jena Fuseki server and run some simple SPARQL queries. Execute the following command in command prompt: $ ./ fuseki −server −−update −−mem / ds If everything goes well, we should have our server running at: http://localhost:3030/ web browser go to http://localhost:3030/ a)Choose control panel then select "/ds" source. b) Upload the file ".owl file” upload it to server c) Now d) To Query triples go to SPARQL query and run it. d) Your database is filled with triples.