问题
I have the ontology used in the OWL API examples.
private static final String KOALA = "<?xml version=\"1.0\"?>\n"
+ "<rdf:RDF xmlns:rdf=\"http://www.w3.org/1999/02/22-rdf-syntax-ns#\" xmlns:rdfs=\"http://www.w3.org/2000/01/rdf-schema#\" xmlns:owl=\"http://www.w3.org/2002/07/owl#\" xmlns=\"http://protege.stanford.edu/plugins/owl/owl-library/koala.owl#\" xml:base=\"http://protege.stanford.edu/plugins/owl/owl-library/koala.owl\">\n"
+ " <owl:Ontology rdf:about=\"\"/>\n"
+ " <owl:Class rdf:ID=\"Female\"><owl:equivalentClass><owl:Restriction><owl:onProperty><owl:FunctionalProperty rdf:about=\"#hasGender\"/></owl:onProperty><owl:hasValue><Gender rdf:ID=\"female\"/></owl:hasValue></owl:Restriction></owl:equivalentClass></owl:Class>\n"
+ " <owl:Class rdf:ID=\"Marsupials\"><owl:disjointWith><owl:Class rdf:about=\"#Person\"/></owl:disjointWith><rdfs:subClassOf><owl:Class rdf:about=\"#Animal\"/></rdfs:subClassOf></owl:Class>\n"
+ " <owl:Class rdf:ID=\"Student\"><owl:equivalentClass><owl:Class><owl:intersectionOf rdf:parseType=\"Collection\"><owl:Class rdf:about=\"#Person\"/><owl:Restriction><owl:onProperty><owl:FunctionalProperty rdf:about=\"#isHardWorking\"/></owl:onProperty><owl:hasValue rdf:datatype=\"http://www.w3.org/2001/XMLSchema#boolean\">true</owl:hasValue></owl:Restriction><owl:Restriction><owl:someValuesFrom><owl:Class rdf:about=\"#University\"/></owl:someValuesFrom><owl:onProperty><owl:ObjectProperty rdf:about=\"#hasHabitat\"/></owl:onProperty></owl:Restriction></owl:intersectionOf></owl:Class></owl:equivalentClass></owl:Class>\n"
+ " <owl:Class rdf:ID=\"KoalaWithPhD\"><owl:versionInfo>1.2</owl:versionInfo><owl:equivalentClass><owl:Class><owl:intersectionOf rdf:parseType=\"Collection\"><owl:Restriction><owl:hasValue><Degree rdf:ID=\"PhD\"/></owl:hasValue><owl:onProperty><owl:ObjectProperty rdf:about=\"#hasDegree\"/></owl:onProperty></owl:Restriction><owl:Class rdf:about=\"#Koala\"/></owl:intersectionOf></owl:Class></owl:equivalentClass></owl:Class>\n"
+ " <owl:Class rdf:ID=\"University\"><rdfs:subClassOf><owl:Class rdf:ID=\"Habitat\"/></rdfs:subClassOf></owl:Class>\n"
+ " <owl:Class rdf:ID=\"Koala\"><rdfs:subClassOf><owl:Restriction><owl:hasValue rdf:datatype=\"http://www.w3.org/2001/XMLSchema#boolean\">false</owl:hasValue><owl:onProperty><owl:FunctionalProperty rdf:about=\"#isHardWorking\"/></owl:onProperty></owl:Restriction></rdfs:subClassOf><rdfs:subClassOf><owl:Restriction><owl:someValuesFrom><owl:Class rdf:about=\"#DryEucalyptForest\"/></owl:someValuesFrom><owl:onProperty><owl:ObjectProperty rdf:about=\"#hasHabitat\"/></owl:onProperty></owl:Restriction></rdfs:subClassOf><rdfs:subClassOf rdf:resource=\"#Marsupials\"/></owl:Class>\n"
+ " <owl:Class rdf:ID=\"Animal\"><rdfs:seeAlso>Male</rdfs:seeAlso><rdfs:subClassOf><owl:Restriction><owl:onProperty><owl:ObjectProperty rdf:about=\"#hasHabitat\"/></owl:onProperty><owl:minCardinality rdf:datatype=\"http://www.w3.org/2001/XMLSchema#int\">1</owl:minCardinality></owl:Restriction></rdfs:subClassOf><rdfs:subClassOf><owl:Restriction><owl:cardinality rdf:datatype=\"http://www.w3.org/2001/XMLSchema#int\">1</owl:cardinality><owl:onProperty><owl:FunctionalProperty rdf:about=\"#hasGender\"/></owl:onProperty></owl:Restriction></rdfs:subClassOf><owl:versionInfo>1.1</owl:versionInfo></owl:Class>\n"
+ " <owl:Class rdf:ID=\"Forest\"><rdfs:subClassOf rdf:resource=\"#Habitat\"/></owl:Class>\n"
+ " <owl:Class rdf:ID=\"Rainforest\"><rdfs:subClassOf rdf:resource=\"#Forest\"/></owl:Class>\n"
+ " <owl:Class rdf:ID=\"GraduateStudent\"><rdfs:subClassOf><owl:Restriction><owl:onProperty><owl:ObjectProperty rdf:about=\"#hasDegree\"/></owl:onProperty><owl:someValuesFrom><owl:Class><owl:oneOf rdf:parseType=\"Collection\"><Degree rdf:ID=\"BA\"/><Degree rdf:ID=\"BS\"/></owl:oneOf></owl:Class></owl:someValuesFrom></owl:Restriction></rdfs:subClassOf><rdfs:subClassOf rdf:resource=\"#Student\"/></owl:Class>\n"
+ " <owl:Class rdf:ID=\"Parent\"><owl:equivalentClass><owl:Class><owl:intersectionOf rdf:parseType=\"Collection\"><owl:Class rdf:about=\"#Animal\"/><owl:Restriction><owl:onProperty><owl:ObjectProperty rdf:about=\"#hasChildren\"/></owl:onProperty><owl:minCardinality rdf:datatype=\"http://www.w3.org/2001/XMLSchema#int\">1</owl:minCardinality></owl:Restriction></owl:intersectionOf></owl:Class></owl:equivalentClass><rdfs:subClassOf rdf:resource=\"#Animal\"/></owl:Class>\n"
+ " <owl:Class rdf:ID=\"DryEucalyptForest\"><rdfs:subClassOf rdf:resource=\"#Forest\"/></owl:Class>\n"
+ " <owl:Class rdf:ID=\"Quokka\"><rdfs:subClassOf><owl:Restriction><owl:hasValue rdf:datatype=\"http://www.w3.org/2001/XMLSchema#boolean\">true</owl:hasValue><owl:onProperty><owl:FunctionalProperty rdf:about=\"#isHardWorking\"/></owl:onProperty></owl:Restriction></rdfs:subClassOf><rdfs:subClassOf rdf:resource=\"#Marsupials\"/></owl:Class>\n"
+ " <owl:Class rdf:ID=\"TasmanianDevil\"><rdfs:subClassOf rdf:resource=\"#Marsupials\"/></owl:Class>\n"
+ " <owl:Class rdf:ID=\"MaleStudentWith3Daughters\"><owl:equivalentClass><owl:Class><owl:intersectionOf rdf:parseType=\"Collection\"><owl:Class rdf:about=\"#Student\"/><owl:Restriction><owl:onProperty><owl:FunctionalProperty rdf:about=\"#hasGender\"/></owl:onProperty><owl:hasValue><Gender rdf:ID=\"male\"/></owl:hasValue></owl:Restriction><owl:Restriction><owl:onProperty><owl:ObjectProperty rdf:about=\"#hasChildren\"/></owl:onProperty><owl:cardinality rdf:datatype=\"http://www.w3.org/2001/XMLSchema#int\">3</owl:cardinality></owl:Restriction><owl:Restriction><owl:allValuesFrom rdf:resource=\"#Female\"/><owl:onProperty><owl:ObjectProperty rdf:about=\"#hasChildren\"/></owl:onProperty></owl:Restriction></owl:intersectionOf></owl:Class></owl:equivalentClass></owl:Class>\n"
+ " <owl:Class rdf:ID=\"Degree\"/>\n <owl:Class rdf:ID=\"Gender\"/>\n"
+ " <owl:Class rdf:ID=\"Male\"><owl:equivalentClass><owl:Restriction><owl:hasValue rdf:resource=\"#male\"/><owl:onProperty><owl:FunctionalProperty rdf:about=\"#hasGender\"/></owl:onProperty></owl:Restriction></owl:equivalentClass></owl:Class>\n"
+ " <owl:Class rdf:ID=\"Person\"><rdfs:subClassOf rdf:resource=\"#Animal\"/><owl:disjointWith rdf:resource=\"#Marsupials\"/></owl:Class>\n"
+ " <owl:ObjectProperty rdf:ID=\"hasHabitat\"><rdfs:range rdf:resource=\"#Habitat\"/><rdfs:domain rdf:resource=\"#Animal\"/></owl:ObjectProperty>\n"
+ " <owl:ObjectProperty rdf:ID=\"hasDegree\"><rdfs:domain rdf:resource=\"#Person\"/><rdfs:range rdf:resource=\"#Degree\"/></owl:ObjectProperty>\n"
+ " <owl:ObjectProperty rdf:ID=\"hasChildren\"><rdfs:range rdf:resource=\"#Animal\"/><rdfs:domain rdf:resource=\"#Animal\"/></owl:ObjectProperty>\n"
+ " <owl:FunctionalProperty rdf:ID=\"hasGender\"><rdfs:range rdf:resource=\"#Gender\"/><rdf:type rdf:resource=\"http://www.w3.org/2002/07/owl#ObjectProperty\"/><rdfs:domain rdf:resource=\"#Animal\"/></owl:FunctionalProperty>\n"
+ " <owl:FunctionalProperty rdf:ID=\"isHardWorking\"><rdfs:range rdf:resource=\"http://www.w3.org/2001/XMLSchema#boolean\"/><rdfs:domain rdf:resource=\"#Person\"/><rdf:type rdf:resource=\"http://www.w3.org/2002/07/owl#DatatypeProperty\"/></owl:FunctionalProperty>\n"
+ " <Degree rdf:ID=\"MA\"/>\n</rdf:RDF>";
I used this code (https://neo4j.com/blog/using-owl-with-neo4j/) to query the owl ontology:
OWLReasoner reasoner = reasonerFactory.createNonBufferingReasoner(ontology);
if (!reasoner.isConsistent()) {
logger.log(Level.INFO, "Ontology is inconsistent");
//throw your exception of choice here
throw new Exception("Ontology is inconsistent");
}
try{
// Node thingNode = getOrCreateNodeWithUniqueFactory("owl:Thing");
for (OWLClass c :ontology.getClassesInSignature(true)) {
String classString = c.toString();
if (classString.contains("#")) {
classString = classString.substring(
classString.indexOf("#")+1,classString.lastIndexOf(">"));
}
System.out.println("classString: "+classString);
// Node classNode = getOrCreateNodeWithUniqueFactory(classString);
NodeSet<OWLClass> superclasses = reasoner.getSuperClasses(c, true);
if (superclasses.isEmpty()) {
//classNode.createRelationshipTo(thingNode,DynamicRelationshipType.withName("isA"));
} else {
for (org.semanticweb.owlapi.reasoner.Node<OWLClass>
parentOWLNode: superclasses) {
OWLClassExpression parent = parentOWLNode.getRepresentativeElement();
String parentString = parent.toString();
if (parentString.contains("#")) {
parentString = parentString.substring(
parentString.indexOf("#")+1,
parentString.lastIndexOf(">"));
}
System.out.println("parentString: "+parentString);
// Node parentNode = getOrCreateNodeWithUniqueFactory(parentString);
// classNode.createRelationshipTo(parentNode, DynamicRelationshipType.withName("isA"));
}
}
for (org.semanticweb.owlapi.reasoner.Node<OWLNamedIndividual> in
: reasoner.getInstances(c, true)) {
OWLNamedIndividual i = in.getRepresentativeElement();
String indString = i.toString();
if (indString.contains("#")) {
indString = indString.substring(
indString.indexOf("#")+1,indString.lastIndexOf(">"));
}
System.out.println("indString: "+indString);
// Node individualNode = getOrCreateNodeWithUniqueFactory(indString);
// individualNode.createRelationshipTo(classNode, DynamicRelationshipType.withName("isA"));
for (OWLObjectPropertyExpression objectProperty:
ontology.getObjectPropertiesInSignature()) { System.out.println("objectProperty: "+objectProperty);
for
(org.semanticweb.owlapi.reasoner.Node<OWLNamedIndividual>
object: reasoner.getObjectPropertyValues(i,
objectProperty)) {
String reltype = objectProperty.toString();
reltype = reltype.substring(reltype.indexOf("#")+1,
reltype.lastIndexOf(">"));
String s =
object.getRepresentativeElement().toString();
s = s.substring(s.indexOf("#")+1,
s.lastIndexOf(">"));
System.out.println("reltype: "+reltype+" s: "+s);
// Node objectNode = getOrCreateNodeWithUniqueFactory(s);
// individualNode.createRelationshipTo(objectNode, DynamicRelationshipType.withName(reltype));
}
}
for (OWLDataPropertyExpression dataProperty:
ontology.getDataPropertiesInSignature()) { System.out.println("dataProperty: "+dataProperty.asOWLDataProperty());
for (OWLLiteral object: reasoner.getDataPropertyValues(
i, dataProperty.asOWLDataProperty())) {
String reltype =
dataProperty.asOWLDataProperty().toString();
reltype = reltype.substring(reltype.indexOf("#")+1,
reltype.lastIndexOf(">"));
String s = object.toString();
System.out.println("reltype: "+reltype+" s: "+s);
// individualNode.setProperty(reltype, s);
}
}
}
}
but I observed that it doesn't return object property values for the specified individual and object property expression.
reasoner.getObjectPropertyValues(i, objectProperty)
returns no items. Why?
I tried even with others Reasoner (HermiT, Pellet) as I read in other post, but the outcome does not change. How can I solve it?
回答1:
There is no objectProperties asserted in the ontology you are using; So the reasoner find nothing, because there is nothing to find.
Add the following code after loading your ontology, so you can test your code.
final OWLDataFactory factory = manager.getOWLDataFactory();
ontology.add(factory.getOWLObjectPropertyAssertionAxiom(factory.getOWLObjectProperty("#HelloWorldProperty"), factory.getOWLNamedIndividual("#FirstIndividual"), factory.getOWLNamedIndividual("#SecondIndividual")));
reasoner.flush();
Your code look good but a bit complicated. You could get shorter code with 'getFlattened()'
for (final OWLNamedIndividual i : reasoner.getInstances(c, true).getFlattened())
回答2:
I could not detect the objectProperties declaration and dataProperties directly from a specific instance, in this block code:
for (org.semanticweb.owlapi.reasoner.Node<OWLNamedIndividual> in
: reasoner.getInstances(c, true)) {
OWLNamedIndividual i = in.getRepresentativeElement();
String indString = i.toString();
if (indString.contains("#")) {
indString = indString.substring(
indString.indexOf("#")+1,indString.lastIndexOf(">"));
}
......
That is, I couldn't find a way to extract these information directly from i. So, I identified all them from ontology in this way:
System.out.println("\n-> ObjectProperties: ");
for (OWLObjectPropertyExpression objectProperty:
ontology.getObjectPropertiesInSignature()) {
String object = objectProperty.toString();
if (object.contains("#")) {
object = object.substring(
object.indexOf("#")+1,object.lastIndexOf(">"));
}
String domain = reasoner.getObjectPropertyDomains(objectProperty, true).toString();
if (domain.contains("#")) {
domain = domain.substring(
domain.indexOf("#")+1,domain.lastIndexOf(">"));
}
String range = reasoner.getObjectPropertyRanges(objectProperty, true).toString();
if (range.contains("#")) {
range = range.substring(
range.indexOf("#")+1,range.lastIndexOf(">"));
}
System.out.println(domain+" "+object+" "+range);
}
System.out.println("\n-> DataProperties: ");
for (OWLDataProperty dataProperty:
ontology.getDataPropertiesInSignature()) {
String data = dataProperty.toString();
if (data.contains("#")) {
data = data.substring(
data.indexOf("#")+1,data.lastIndexOf(">"));
}
String domain = reasoner.getDataPropertyDomains(dataProperty, true).toString();
if (domain.contains("#")) {
domain = domain.substring(
domain.indexOf("#")+1,domain.lastIndexOf(">"));
}
System.out.println(domain+" "+data);
}
I thought to add an edge like domain->(objectProperty)->range for all objectProperties found, in order to not lose this information.
来源：https://stackoverflow.com/questions/46606072/problems-querying-owl-ontology-through-owl-api