First of all, I created my own, sample ontology using Protege 4. My actual goal is developing a semantic web application that benefits from object properties to offer something to users. After I created my ontology, I'll add dynamic data, so I need to use *Jena API *. For the sake of demonstration I created sample instances. But when I try to retrieve results, I got nothing.
Maybe I'm missing something in my SPARQL query.
private static final String baseUri = "http://www.semanticweb.org/ontologies/alisveris.owl#";
private static void modelReadFile(String filename, Model model) {
try {
File f = new File(filename);
FileReader fr = new FileReader(f);
model.read(fr, baseUri);
} catch (FileNotFoundException e) {
e.printStackTrace();
}
}
private static void printModel(Model model) {
String queryString =
"PREFIX lib: <http://www.semanticweb.com/ontologies/alisveris.owl>" +
"SELECT ?name ?surname " +
"FROM <http://www.semanticweb.com/ontologies/alisveris.owl>" +
"WHERE {" +
"?name lib:take \"JavaProgramming\" " +
"}";
System.out.println(queryString);
Query query = QueryFactory.create(queryString);
QueryExecution qe = QueryExecutionFactory.create(query, model);
ResultSet results = qe.execSelect();
ResultSetFormatter.out(System.out, results, query);
qe.close();
}
public static void main(String[] args) {
Model model = ModelFactory.createDefaultModel();
modelReadFile("/home/talha/ontologies/alisveris.owl", model);
// Create properties for the different types of relationship to represent
Property take = model.createProperty(baseUri, "take");
Property isTakenBy = model.createProperty(baseUri, "isTakenBy");
Property published = model.createProperty(baseUri, "published");
Property publishedBy = model.createProperty(baseUri, "publishedBy");
// User data properties
Property userId = model.createProperty(baseUri, "userId");
Property name = model.createProperty(baseUri, "name");
Property surname = model.createProperty(baseUri, "surname");
Property username = model.createProperty(baseUri, "username");
Property password = model.createProperty(baseUri, "password");
Property gender = model.createProperty(baseUri, "gender");
Property age = model.createProperty(baseUri, "age");
// Publisher data properties
Property publisherId = model.createProperty(baseUri, "publisherId");
Property publisherName = model.createProperty(baseUri, "publisherName");
// Book data properties
Property bookId = model.createProperty(baseUri, "bookId");
Property bookName = model.createProperty(baseUri, "bookName");
Property bookGenre = model.createProperty(baseUri, "bookGenre");
Property pageCount = model.createProperty(baseUri, "pageCount");
Property isbn = model.createProperty(baseUri, "isbn");
Property bookRating = model.createProperty(baseUri, "bookRating");
Resource talha = model.createResource(baseUri + "Talha");
Resource javaProgramming = model.createResource(baseUri + "JavaProgramming");
// and so on for other family members
talha.addProperty(userId, "1");
talha.addProperty(name, "Talha");
talha.addProperty(surname, "Kabakuş");
talha.addProperty(username, "talhak");
talha.addProperty(password, "00");
talha.addProperty(gender, "1");
talha.addProperty(age, "23");
javaProgramming.addProperty(bookId, "1");
javaProgramming.addProperty(publisherId, "1");
javaProgramming.addProperty(bookName, "Java Programming");
javaProgramming.addProperty(bookGenre, "1");
javaProgramming.addProperty(pageCount, "200");
javaProgramming.addProperty(isbn, "121321312");
javaProgramming.addProperty(bookRating, "3");
// Add properties to adam describing relationships to other family members
talha.addProperty(take, javaProgramming);
Statement s = ResourceFactory.createStatement(talha, take, javaProgramming);
model.add(s); // add the statement (triple) to the model
printModel(model);
}
Here's the results I got:
------------------
| name | surname |
==================
------------------
Finally my sample ontology:
<?xml version="1.0"?>
<!DOCTYPE rdf:RDF [
<!ENTITY owl "http://www.w3.org/2002/07/owl#" >
<!ENTITY xsd "http://www.w3.org/2001/XMLSchema#" >
<!ENTITY rdfs "http://www.w3.org/2000/01/rdf-schema#" >
<!ENTITY rdf "http://www.w3.org/1999/02/22-rdf-syntax-ns#" >
<!ENTITY alisveris "http://www.semanticweb.org/ontologies/alisveris.owl#" >
]>
<rdf:RDF xmlns="http://www.semanticweb.org/ontologies/alisveris.owl#"
xml:base="http://www.semanticweb.org/ontologies/alisveris.owl"
xmlns:rdfs="http://www.w3.org/2000/01/rdf-schema#"
xmlns:owl="http://www.w3.org/2002/07/owl#"
xmlns:xsd="http://www.w3.org/2001/XMLSchema#"
xmlns:rdf="http://www.w3.org/1999/02/22-rdf-syntax-ns#"
xmlns:alisveris="http://www.semanticweb.org/ontologies/alisveris.owl#">
<owl:Ontology rdf:about="http://www.semanticweb.org/ontologies/alisveris.owl"/>
<!--
///////////////////////////////////////////////////////////////////////////////////////
//
// Object Properties
//
///////////////////////////////////////////////////////////////////////////////////////
-->
<!-- http://www.semanticweb.org/ontologies/alisveris.owl#isTakenBy -->
<owl:ObjectProperty rdf:about="&alisveris;isTakenBy">
<rdfs:domain rdf:resource="&alisveris;Book"/>
<rdfs:range rdf:resource="&alisveris;User"/>
</owl:ObjectProperty>
<!-- http://www.semanticweb.org/ontologies/alisveris.owl#published -->
<owl:ObjectProperty rdf:about="&alisveris;published">
<rdfs:range rdf:resource="&alisveris;Book"/>
<rdfs:domain rdf:resource="&alisveris;Publisher"/>
</owl:ObjectProperty>
<!-- http://www.semanticweb.org/ontologies/alisveris.owl#publishedBy -->
<owl:ObjectProperty rdf:about="&alisveris;publishedBy">
<rdfs:domain rdf:resource="&alisveris;Book"/>
<rdfs:range rdf:resource="&alisveris;Publisher"/>
<owl:inverseOf rdf:resource="&alisveris;published"/>
</owl:ObjectProperty>
<!-- http://www.semanticweb.org/ontologies/alisveris.owl#take -->
<owl:ObjectProperty rdf:about="&alisveris;take">
<rdfs:range rdf:resource="&alisveris;Book"/>
<rdfs:domain rdf:resource="&alisveris;User"/>
<owl:inverseOf rdf:resource="&alisveris;isTakenBy"/>
</owl:ObjectProperty>
<!--
///////////////////////////////////////////////////////////////////////////////////////
//
// Data properties
//
///////////////////////////////////////////////////////////////////////////////////////
-->
<!-- http://www.semanticweb.org/ontologies/alisveris.owl#age -->
<owl:DatatypeProperty rdf:about="&alisveris;age">
<rdfs:domain rdf:resource="&alisveris;User"/>
</owl:DatatypeProperty>
<!-- http://www.semanticweb.org/ontologies/alisveris.owl#bookGenre -->
<owl:DatatypeProperty rdf:about="&alisveris;bookGenre">
<rdfs:domain rdf:resource="&alisveris;Book"/>
</owl:DatatypeProperty>
<!-- http://www.semanticweb.org/ontologies/alisveris.owl#bookId -->
<owl:DatatypeProperty rdf:about="&alisveris;bookId">
<rdfs:domain rdf:resource="&alisveris;Book"/>
</owl:DatatypeProperty>
<!-- http://www.semanticweb.org/ontologies/alisveris.owl#bookName -->
<owl:DatatypeProperty rdf:about="&alisveris;bookName">
<rdfs:domain rdf:resource="&alisveris;Book"/>
</owl:DatatypeProperty>
<!-- http://www.semanticweb.org/ontologies/alisveris.owl#bookRating -->
<owl:DatatypeProperty rdf:about="&alisveris;bookRating">
<rdfs:domain rdf:resource="&alisveris;Book"/>
</owl:DatatypeProperty>
<!-- http://www.semanticweb.org/ontologies/alisveris.owl#gender -->
<owl:DatatypeProperty rdf:about="&alisveris;gender">
<rdfs:domain rdf:resource="&alisveris;User"/>
</owl:DatatypeProperty>
<!-- http://www.semanticweb.org/ontologies/alisveris.owl#isbn -->
<owl:DatatypeProperty rdf:about="&alisveris;isbn">
<rdfs:domain rdf:resource="&alisveris;Book"/>
</owl:DatatypeProperty>
<!-- http://www.semanticweb.org/ontologies/alisveris.owl#name -->
<owl:DatatypeProperty rdf:about="&alisveris;name">
<rdfs:domain rdf:resource="&alisveris;User"/>
</owl:DatatypeProperty>
<!-- http://www.semanticweb.org/ontologies/alisveris.owl#pageCount -->
<owl:DatatypeProperty rdf:about="&alisveris;pageCount">
<rdfs:domain rdf:resource="&alisveris;Book"/>
</owl:DatatypeProperty>
<!-- http://www.semanticweb.org/ontologies/alisveris.owl#password -->
<owl:DatatypeProperty rdf:about="&alisveris;password">
<rdfs:domain rdf:resource="&alisveris;User"/>
</owl:DatatypeProperty>
<!-- http://www.semanticweb.org/ontologies/alisveris.owl#publisherId -->
<owl:DatatypeProperty rdf:about="&alisveris;publisherId">
<rdfs:domain rdf:resource="&alisveris;Book"/>
<rdfs:domain rdf:resource="&alisveris;Publisher"/>
</owl:DatatypeProperty>
<!-- http://www.semanticweb.org/ontologies/alisveris.owl#publisherName -->
<owl:DatatypeProperty rdf:about="&alisveris;publisherName">
<rdfs:domain rdf:resource="&alisveris;Publisher"/>
</owl:DatatypeProperty>
<!-- http://www.semanticweb.org/ontologies/alisveris.owl#rating -->
<owl:DatatypeProperty rdf:about="&alisveris;rating"/>
<!-- http://www.semanticweb.org/ontologies/alisveris.owl#surname -->
<owl:DatatypeProperty rdf:about="&alisveris;surname">
<rdfs:domain rdf:resource="&alisveris;User"/>
</owl:DatatypeProperty>
<!-- http://www.semanticweb.org/ontologies/alisveris.owl#userId -->
<owl:DatatypeProperty rdf:about="&alisveris;userId">
<rdfs:domain rdf:resource="&alisveris;User"/>
</owl:DatatypeProperty>
<!-- http://www.semanticweb.org/ontologies/alisveris.owl#username -->
<owl:DatatypeProperty rdf:about="&alisveris;username">
<rdfs:domain rdf:resource="&alisveris;User"/>
</owl:DatatypeProperty>
<!--
///////////////////////////////////////////////////////////////////////////////////////
//
// Classes
//
///////////////////////////////////////////////////////////////////////////////////////
-->
<!-- http://www.semanticweb.org/ontologies/alisveris.owl#Book -->
<owl:Class rdf:about="&alisveris;Book">
<owl:disjointWith rdf:resource="&alisveris;Publisher"/>
</owl:Class>
<!-- http://www.semanticweb.org/ontologies/alisveris.owl#Female -->
<owl:Class rdf:about="&alisveris;Female">
<rdfs:subClassOf rdf:resource="&alisveris;Gender"/>
<owl:disjointWith rdf:resource="&alisveris;Male"/>
</owl:Class>
<!-- http://www.semanticweb.org/ontologies/alisveris.owl#Gender -->
<owl:Class rdf:about="&alisveris;Gender"/>
<!-- http://www.semanticweb.org/ontologies/alisveris.owl#Male -->
<owl:Class rdf:about="&alisveris;Male">
<rdfs:subClassOf rdf:resource="&alisveris;Gender"/>
</owl:Class>
<!-- http://www.semanticweb.org/ontologies/alisveris.owl#Publisher -->
<owl:Class rdf:about="&alisveris;Publisher">
<rdfs:subClassOf rdf:resource="&owl;Thing"/>
</owl:Class>
<!-- http://www.semanticweb.org/ontologies/alisveris.owl#User -->
<owl:Class rdf:about="&alisveris;User"/>
</rdf:RDF>
This answer is also at the duplicate on answers.semanticweb.com.
Your query is asking for a triple in which the object is the literal "JavaProgramming", but the code Resource javaProgramming = model.createResource(baseUri + "JavaProgramming"); creates a resource. You need to query for the resource rather than a string. The model that you create, aside from the ontology code, is this (notice that we see :JavaProgramming, and not "JavaProgramming"):
@prefix : <http://www.semanticweb.org/ontologies/alisveris.owl#> .
:JavaProgramming :bookGenre "1" ;
:bookId "1" ;
:bookName "Java Programming" ;
:bookRating "3" ;
:isbn "121321312" ;
:pageCount "200" ;
:publisherId "1" .
:Talha :age "23" ;
:gender "1" ;
:name "Talha" ;
:password "00" ;
:surname "Kabakuş" ;
:take :JavaProgramming ;
:userId "1" ;
:username "talhak" .
On this data, you can run the following query (with :JavaProgramming) and get the following results.
prefix : <http://www.semanticweb.org/ontologies/alisveris.owl#>
select ?student ?name ?surname where {
?student :take :JavaProgramming ;
:name ?name ;
:surname ?surname .
}
---------------------------------
| student | name | surname |
=================================
| :Talha | "Talha" | "Kabakuş" |
---------------------------------