how to do reasoning in Jena via Sparql Query

Question

I\'m using Jena and Sparql to query the ontology file.

I have

1. class Tag with two subclasses : C++ and Java.
2. class Subject with several subclasse

Answer 1

You need to ask for things that are subclasses of Tag. Thus, something like

?class rdfs:subClassOf* :Tag

The * means you need to match a path of 0 or more occurrences of rdfs:subClassOf, so ?class can be Tag, or a subclass of Tag, or or subclass of a subclass of Tag, etc. A complete working query would be:

prefix :       
prefix owl:    
prefix rdfs:   

select distinct ?subject where {
   ?subject owl:equivalentClass ?restriction .
   ?restriction owl:onProperty :hasTags .
   ?restriction ?restrictType ?class .
   ?class rdfs:subClassOf* :Tag 
}

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| subject                                                                                 |
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| :Java_programming                                                                       |
|  |
| :System_Programming                                                                     |
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