Hi Ian,
From your answer above it looks like Jena does allow to create
individuals, delete/add classes, statements and properties to the loaded
owl ontology model
directly from the java file. I guess the question is how? I would like to
focus our exchange back to a real case to illustrate part of my problem
using the excerpt below. I've loaded the wine ontology (.owl) in an empty
model and would like to write code to enrich/modify that ontology (see the
various methods listed). Do you or anyone have example code to help fill in
the gaps?
TestWine.java
package demo;
import java.io.BufferedReader;
import java.io.File;
import java.io.FileNotFoundException;
import java.io.IOException;
import java.io.InputStreamReader;
import java.util.Iterator;
import java.util.List;
import com.hp.hpl.jena.rdf.model.InfModel;
import com.hp.hpl.jena.rdf.model.Literal;
import com.hp.hpl.jena.rdf.model.Model;
import com.hp.hpl.jena.rdf.model.ModelFactory;
import com.hp.hpl.jena.rdf.model.Property;
import com.hp.hpl.jena.rdf.model.RDFNode;
import com.hp.hpl.jena.rdf.model.ResIterator;
import com.hp.hpl.jena.rdf.model.Resource;
import com.hp.hpl.jena.rdf.model.Statement;
import com.hp.hpl.jena.rdf.model.StmtIterator;
import com.hp.hpl.jena.reasoner.Reasoner;
import com.hp.hpl.jena.reasoner.ReasonerRegistry;
import com.hp.hpl.jena.reasoner.ValidityReport;
import com.hp.hpl.jena.reasoner.rulesys.GenericRuleReasoner;
import com.hp.hpl.jena.reasoner.rulesys.Rule;
import com.hp.hpl.jena.shared.DoesNotExistException;
import com.hp.hpl.jena.util.FileManager;
import com.hp.hpl.jena.util.PrintUtil;
import com.hp.hpl.jena.vocabulary.RDF;
import com.hp.hpl.jena.vocabulary.VCARD;
// Create an instance of the OWL reasoner, specialized to the demo schema
// and then apply that to the demo data to obtain an inference model.
public class TestWineOntologyOWL {
private Model model;
String ontURL = "src/demo/ont/wine.owl";
// constructor
public TestWineOntologyOWL() {
model = FileManager.get().loadModel( ontURL );
}
// ============================================================
// Create and add individuals ...
// ============================================================
public void addIndividuals() {
//????
}
// ============================================================
// Create and add properties ...
// ============================================================
public void addProperties() {
//????
}
// ============================================================
// Create and add Resources ...
// ============================================================
public void addResource() {
//????
}
// ============================================================
// Create and add Statements ...
// ============================================================
public void addStatements() {
//????
}
// ============================================================
// Remove or replace individuals, property, resource, Statements,
etc.....
// ============================================================
public void remove() {
//????
}
// ============================================================
// Retrieve and print the RDF statements ....
// ============================================================
public void printStatements( String sTitle ) {
int statementNo = 1;
System.out.printf("List of statements: %s\n", sTitle );
System.out.printf(
"=============================================================\n");
StmtIterator iter = model.listStatements();
while (iter.hasNext()) {
Statement stmt = iter.next(); // get next statement
Resource subject = stmt.getSubject(); // get the subject
Property predicate = stmt.getPredicate(); // get the predicate
RDFNode object = stmt.getObject(); // get the object
// Objects can be either Resources or Literals ....
System.out.printf(" Statement[%4d]\n", statementNo );
System.out.printf(" Subject : %s \n", subject.toString());
System.out.printf(" Predicate: %s \n", predicate.toString());
if (object instanceof Resource) {
System.out.printf(" Object : %s \n", object.toString());
}
if (object instanceof Literal) {
System.out.printf(" Object : \"%s\" \n", object.toString());
}
statementNo = statementNo + 1;
}
System.out.println(
"=============================================================");
}
public static void main(String[] args) {
System.out.println("Step 1: Load the Wine Ontology ....
");
System.out.println(
"===================================================");
TestWineOntologyOWL wine = new TestWineOntologyOWL();
System.out.printf("Step 2: Print size of the Wine Ontology ...\n");
System.out.println(
"===================================================");
System.out.println("");
System.out.println("Wine ontology model size = " + wine.model
.size());
System.out.println("");
System.out.printf("Step 3: Print details of the Wine Ontology ...\n");
System.out.println("===============================================");
System.out.println("");
wine.model.write(System.out, "RDF/XML" );
System.out.println("");
System.out.println("");
System.out.println("===============================================");
System.out.printf("Step 4: extend/modify the Wine Ontology ...\n");
System.out.println("===============================================");
System.out.println("");
wine.addIndividuals( );
wine.addProperties();
wine.addResources();
System.out.println("");
System.out.println("===============================================");
System.out.printf("Step 5: Print statements in the Wine Ontology
...\n");
System.out.println("===============================================");
System.out.println("");
wine.printStatements( "Wine Ontology" );
System.out.println("");
System.out.println(
"===============================================");
}
Thank,
Leonard
2013/4/24 Ian Dickinson <[email protected]>
> On 24/04/13 04:24, Léonard PETNGA wrote:
>
>> Hi Ian!
>> Thank you for your prompt response to my email. I didn't mention it but,
>> as
>> far as my objectives are concerned, my 2 questions are not related. These
>> are some clarifications to my initial post.
>> Q1: I just wanted to know whether it's possible to create the the owl
>> file
>> from the java version of the ontology since I was programatically
>> creating it in jAVA. Thank you for letting me know about Jena's
>> schemagen
>> tool. I'll keep that in mind.
>>
> OK. To clarify: schemagen takes an OWL file and creates a corresponding
> Java file with constants that correspond to the classes, properties and
> individuals in the ontology. It does not go from Java to OWL, but vice
> versa.
>
>
> Q2: I have decided to encode the ontologies in Java because I wasn't able
>> to programatically access and modify the owl file after being loaded.
>>
> Um, I'm not sure I understand this. Programatically accessing and modify
> RDF and OWL is what Jena does.
>
>
> Specifically, i wanted to be able to create individuals, delete/add
>> classes, statements and properties to the loaded owl ontology model
>> directly from the java file.
>>
> Yep, Jena does that.
>
>
> Jena and Eclipse were unable to recognize
>> ontology's entities and wanted them to be declared as local variable,
>>
> Having Java constants that correspond to OWL or RDFS resources is exactly
> the problem that schemagen solves.
>
>
> thus
>> the duplicate elements i mentioned previously.
>>
> But now I'm lost.
>
>
> Being able to merge those
>> ontologies from the Java encoding directly would also save me a lot of
>> time
>> and energy as I've already put a lot of effort in coding the ontology in
>> java. So there is no way to merge my java encoding ontologies as I
>> mentioned in my initial post?
>>
> Sorry, but you're doing something that no-one else that I know of is
> doing. You're on your own, I'm afraid! I suppose you *could* download a
> Java parser, parse your .java files and generate a new file with the merged
> definitions in. Personally I wouldn't go there, but it's your call.
>
>
> Note: I have developed several built-ins that are being used by my
>> reasoner
>> for inferencing applied to the base ontology created in java. The java
>> encoding allows me to test those built-ins separately before integrating
>> them in with rule engine something I can't do if the original ontologies
>> are in owl (I mean I don't know how to do it - any idea will be welcome
>> though).
>>
> I don't understand enough of what you're trying to do to offer any useful
> comments. If you wanted to create a *minimal* complete example of what
> you're trying to do, we could maybe offer more advice.
>
> Ian
>
>
