First configure the path of the operation ontology (match your own path):
//The name of the owl file changes as the owl file changes.
String metaName = "newmeta_11.owl";
//The IRI of the owl file changes as the owl file changes.
String ontologyIRI = "http://www.semanticweb.org/asus/ontologies/2022/6/untitled-ontology-23";
/**
* Try to load the metadata file, try to find the latest version of the metadata file, and read the owl file without restarting the project.
*/
public void reloadMetaFile() throws OWLOntologyCreationException, FileNotFoundException {
String metaFile = metadataService.getLatestMetafile();
metadataService.reload(metaFile);
}
The following is the use of java code to operate OWL ontology classes:
Add ontology class Controller layer:
/**
* Add ontology class
*
* @param className subclass name, also the ontology class to be added
* @param parentClassName parent class name
* @return QueryResponse
*/
@RequestMapping(value = "/addClass", produces = "application/json;charset=UTF-8", method = RequestMethod.POST)
public QueryResponse addClass(@RequestParam(value = "className", defaultValue = "") String className,
@RequestParam(value = "parentClassName", defaultValue = "") String parentClassName) {
return metadataEditService.addClass(className, parentClassName);
}
Service layer:
/**
* Add ontology class
*
* @param className The class name to be added
* @param parentClassName parent class name
* @return QueryResponse
*/
public QueryResponse addClass(String className, String parentClassName) {
QueryResponse response = new QueryResponse();
JSONObject jsonObject = new JSONObject();
// Get the path of the owl file
String metaPath = sysConfig.getMetadata() + "/";
try {
File file = new File(metaPath + metaName);
OWLOntologyManager manager = OWLManager.createOWLOntologyManager();
//Load the file and convert it into an ontology object. At this time, ontology is the ontology that has been obtained.
OWLOntology ontology = manager.loadOntologyFromOntologyDocument(file);
// Get the ontology data factory
OWLDataFactory factory = manager.getOWLDataFactory();
// Set of axioms added to the basic statements expressed by the ontology
Set<OWLDeclarationAxiom> axiomSet = new HashSet<>();
List<String> classList = new ArrayList<>();
// Get all classes
List<OWLClass> classes = new ArrayList<>(ontology.getClassesInSignature());
//Save the class name into the class collection
for (OWLClass aClass : classes) {
classList.add(aClass.getIRI().getFragment().toString());
}
//Remove all spaces, including spaces in between
String removeSpacesClassName = className.replaceAll(" ", "");
//Use tool class to determine whether it is empty
if (!StringUtil.isEmpty(removeSpacesClassName)) {
// Determine whether the ontology class to be added already exists
if (!classList.contains(removeSpacesClassName)) {
//Create the IRI of the new class and keep the format consistent
IRI classIRI = IRI.create(ontologyIRI + "#" + removeSpacesClassName);
if (parentClassName.isEmpty()) {
// If the parent class is empty, create the subclass directly
OWLClass name = factory.getOWLClass(classIRI);
//Add class
axiomSet.add(factory.getOWLDeclarationAxiom(name));
//Add completed
manager.addAxioms(ontology, axiomSet);
//Save the picture
manager.saveOntology(ontology, new TurtleDocumentFormat(), IRI.create(file.toURI()));
response.setSuccess(true);
log.info("Add ontology class successfully!");
response.setMsg("Add ontology class successfully!");
} else {
// Get the parent class
OWLClass superclass = ontology.classesInSignature()
.filter(owlClass -> owlClass.getIRI().getRemainder().get().equals(parentClassName))
.findFirst()
.get();
//Create subclass
OWLClass subclass = factory.getOWLClass(classIRI);
//Define the relationship between subclasses and parent classes
Set<OWLAxiom> subAndSuper = new HashSet<>();
subAndSuper.add(factory.getOWLSubClassOfAxiom(subclass, superclass));
//Add subclass and parent class relationships to the ontology
manager.addAxioms(ontology, subAndSuper.stream());
manager.addAxioms(ontology, axiomSet);
}
//Save the body
manager.saveOntology(ontology, new TurtleDocumentFormat(), IRI.create(file.toURI()));
response.setSuccess(true);
log.info("Add ontology class successfully!");
response.setMsg("Add ontology class successfully!");
} else {
response.setSuccess(false);
log.info("This concept already exists, adding the ontology class failed!");
return QueryResponse.genErr("This concept already exists, adding ontology class failed!");
}
//Try to load the metadata file, try to find the latest version of the metadata file, and read the owl file without restarting the project
reloadMetaFile();
} else {
response.setSuccess(false);
log.info("New concepts cannot be empty!");
return QueryResponse.genErr("The new concept cannot be empty!");
}
} catch (OWLOntologyCreationException | OWLOntologyStorageException | FileNotFoundException e) {
e.printStackTrace();
response.setSuccess(false);
log.info("Failed to add ontology class!");
return QueryResponse.genErr("Failed to add ontology class!");
}
return response;
}
Delete the ontology class Controller layer:
/**
* Delete the ontology class
*
* @param removeClassName The name of the ontology class to be deleted
* @return QueryResponse
*/
@RequestMapping(value = "/removeClass", produces = "application/json;charset=UTF-8", method = RequestMethod.POST)
public QueryResponse removeClass(@RequestParam(value = "removeClassName", defaultValue = "") String removeClassName) {
return metadataEditService.removeClass(removeClassName);
}
Service layer:
/**
* Delete the ontology class
*
* @param removeClassName The name of the class to be deleted
* @return QueryResponse
*/
public QueryResponse removeClass(String removeClassName) {
QueryResponse response = new QueryResponse();
JSONObject jsonObject = new JSONObject();
//Get the path of the owl file
String metaPath = sysConfig.getMetadata() + "/";
try {
OntologyHelper helper = new OntologyHelper();
//Load file
File file = new File(metaPath + metaName);
OWLOntology ontology = helper.readOntology(file);
//Our removeClassName here gives the added class name above, obtains all classes through the ontology class, traverses and gets the removeClassName class
OWLClass aClass = ontology.classesInSignature()
.filter(owlClass -> owlClass.getIRI().getRemainder().get().equals(removeClassName))
.findFirst()
.get();
//To delete, use the OWLAxiom class
Set<OWLAxiom> axiomsToRemove = new HashSet<OWLAxiom>();
//Start traversing
for (OWLAxiom ax : ontology.getAxioms()) {
//Put it in when it is found that the class in the collection is the same as the class to be deleted
if (ax.getSignature().contains(aClass)) {
axiomsToRemove.add(ax);
}
}
//Perform deletion operation
helper.removeAxioms(ontology, axiomsToRemove);
helper.writeOntology(ontology, file, "owl");
response.setSuccess(true);
log.info("Delete ontology class successfully!");
response.setMsg("Delete ontology class successfully!");
} catch (OWLOntologyCreationException | OWLOntologyStorageException e) {
e.printStackTrace();
response.setSuccess(false);
log.info("Deletion of ontology class failed!");
return QueryResponse.genErr("Failed to delete ontology class!");
}
return response;
}