A recent project related to knowledge graphs used the jena framework to operate OWL files, but no suitable tutorials were found on the entire network, so I slowly tried to learn by myself, and then encapsulated a tool class for operating OWL for easy use, if necessary Take it yourself.
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Put the dependency first
<dependency>
<groupId>org.apache.jena</groupId>
<artifactId>apache-jena-libs</artifactId>
<type>pom</type>
<version>3.6.0</version>
</dependency>
The specific tool class code is as follows
import org.apache.jena.ontology.*;
import org.apache.jena.rdf.model.ModelFactory;
import org.apache.jena.rdf.model.RDFWriter;
import org.springframework.stereotype.Component;
import javax.swing.plaf.ViewportUI;
import java.io.FileOutputStream;
import java.io.IOException;
/**
* @BelongsProject: createowl
* @BelongsPackage: com.zt.createowl.util
* @Author: zt
* @CreateTime: 2023-02-28 15:59
* @Description:
*/
@Component
public class CoreOWLUtil {
/*
* @Description: Returns the resource beginning name of the OWL file
* @Author: zt
* @Date: 2023/2/28 16:23
* @param: []
* @return: java.lang.String
**/
public static String getSourceName(){
return "http://www.semanticweb.org/ztyt/ontologies/2023/2/fkfdcore";
}
/*
* @Description: Return the namespace of the OWL file (add # on the basis of the beginning name)
* @Author: zt
* @Date: 2023/2/28 16:26
* @param: []
* @return: java.lang.String
**/
public static String getNameSpace(){
return CoreOWLUtil. getSourceName() + "#";
}
/*
* @Description: Write the object of OntModel class as an OWL file
* @Author: zt
* @Date: 2023/2/28 16:37
* @param: [ontModel]
* @return: void
**/
public static void ontModel2Owl(OntModel ontModel) throws IOException {
//Output the owl file to the file system
String filepath = "src/main/resources/owl/core/CoreOntology.owl";
FileOutputStream fileOS = new FileOutputStream(filepath);
// RDFWriter rdfWriter = baseOnt. getWriter("RDF/XML");
RDFWriter rdfWriter = ontModel. getWriter("RDF/XML");
rdfWriter.setProperty("showXMLDeclaration","true");
rdfWriter.setProperty("showDoctypeDeclaration", "true");
rdfWriter.write(ontModel, fileOS, null);
//With writer, you don't need to use the following method
//baseOnt.write(fileOS, "RDF/XML");
fileOS. close();
}
/*
* @Description: Read the OWL file at the specified location as an object of the OntModel class
* @Author: zt
* @Date: 2023/2/28 16:05
* @param: []
* @return: org.apache.jena.ontology.OntModel
**/
public static OntModel owl2OntModel(){
//Set the namespace of the ontology
String SOURCE = CoreOWLUtil. getSourceName();
OntDocumentManager ontDocMgr = new OntDocumentManager();
//Set the location of the ontology owl file
ontDocMgr.addAltEntry(SOURCE, "file:src/main/resources/owl/core/CoreOntology.owl");
OntModelSpec ontModelSpec = new OntModelSpec(OntModelSpec.OWL_MEM);
ontModelSpec.setDocumentManager(ontDocMgr);
// asserted ontology
OntModel baseOnt = ModelFactory. createOntologyModel(ontModelSpec);
baseOnt.read(SOURCE, "RDF/XML");
return baseOnt;
}
/*
* @Description: Add a new class
* @Author: zt
* @Date: 2023/2/28 16:38
* @param: [ontModel reads the OntModel class object generated by the OWL file, className adds the name of the new class]
* @return: org.apache.jena.ontology.OntClass
**/
public static OntClass createClass(OntModel ontModel, String className) throws IOException {
String nameSpace = CoreOWLUtil. getNameSpace();
OntClass newClass = ontModel. createClass(nameSpace + className);
CoreOWLUtil.ontModel2Owl(ontModel);
return newClass;
}
/*
* @Description: Add a parent-child relationship to the incoming parent and child classes
* @Author: zt
* @Date: 2023/2/28 16:53
* @param: [ontModel reads the OntModel class object generated from the OWL file, fatherClass parent class, sonClass subclass]
* @return: void
**/
public static void addSubClass(OntModel ontModel, OntClass fatherClass, OntClass sonClass) throws IOException {
fatherClass.addSubClass(sonClass);
CoreOWLUtil.ontModel2Owl(ontModel);
}
/*
* @Description: Add a relationship between the incoming head class and tail class, the name of the relationship is passed by the parameter
* @Author: zt
* @Date: 2023/2/28 17:11
* @param: [ontModel reads the OntModel class object generated from the OWL file, sourceClass head class, targetClass tail class, relationName relation name]
* @return: org.apache.jena.ontology.ObjectProperty
**/
public static ObjectProperty addRelation(OntModel ontModel, OntClass sourceClass, OntClass targetClass, String relationName) throws IOException {
String nameSpace = CoreOWLUtil. getNameSpace();
ObjectProperty newRelation = ontModel.createObjectProperty(nameSpace + relationName);
newRelation. addDomain(sourceClass);
newRelation. addRange(targetClass);
CoreOWLUtil.ontModel2Owl(ontModel);
return newRelation;
}
/*
* @Description: Add attribute information to the incoming class, the attribute name is passed by the parameter
* @Author: zt
* @Date: 2023/2/28 17:23
* @param: [ontModel reads the OntModel class object generated from the OWL file, ontClass the category that needs to be added, propertyName the property name]
* @return: org.apache.jena.ontology.DatatypeProperty
**/
public static DatatypeProperty addProperty(OntModel ontModel, OntClass ontClass, String propertyName) throws IOException {
String nameSpace = CoreOWLUtil. getNameSpace();
DatatypeProperty newProperty = ontModel.createDatatypeProperty(nameSpace + propertyName);
newProperty. addDomain(ontClass);
CoreOWLUtil.ontModel2Owl(ontModel);
return newProperty;
}
/*
* @Description: Delete the attribute information in the specified class
* @Author: zt
* @Date: 2023/3/27 15:39
* @param: [ontModel, ontClass, propertyName]
* @return: void
**/
public static void removeProperty(OntModel ontModel, OntClass ontClass, String propertyName) throws IOException {
String nameSpace = CoreOWLUtil. getNameSpace();
DatatypeProperty newProperty = ontModel.createDatatypeProperty(nameSpace + propertyName);
newProperty. removeDomain(ontClass);
CoreOWLUtil.ontModel2Owl(ontModel);
}
/*
* @Description: Delete the class with the specified name. If this class has subclasses, it cannot be deleted and an exception is thrown directly
* @Author: zt
* @Date: 2023/2/28 18:18
* @param: [ontModel reads the OntModel class object generated by the OWL file, classname is the name of the class to be deleted]
* @return: void
**/
public static void removeClass(OntModel ontModel, String classname) throws Exception {
OntClass ontClass = CoreOWLUtil.createClass(ontModel, classname);
ontClass. remove();
CoreOWLUtil.ontModel2Owl(ontModel);
}
/*
* @Description: Delete the specified domain and range in the relationship with the specified name
* @Author: zt
* @Date: 2023/3/7 10:42
* @param: [ontModel, propertyName the name of the relationship, ontClass the class to remove from this relationship]
* @return: void
**/
public static void removeRelationDomainAndRange(OntModel ontModel, String propertyName, OntClass ontClass) throws IOException {
String nameSpace = CoreOWLUtil. getNameSpace();
ObjectProperty relation = ontModel.createObjectProperty(nameSpace + propertyName);
//As long as this class is the range or domain of this relationship, delete it
if(relation.hasDomain(ontClass)){
relation. removeDomain(ontClass);
}
if(relation.hasRange(ontClass)){
relation. removeRange(ontClass);
}
CoreOWLUtil.ontModel2Owl(ontModel);
}
public static void removeRelation(OntModel ontModel, String propertyName, OntClass domain, OntClass range) throws IOException {
String nameSpace = CoreOWLUtil. getNameSpace();
ObjectProperty relation = ontModel.createObjectProperty(nameSpace + propertyName);
if(relation.hasDomain(domain)){
relation. removeDomain(domain);
}
if(relation.hasRange(range)){
relation. removeRange(range);
}
CoreOWLUtil.ontModel2Owl(ontModel);
}
}
Please modify the specific OWL file path and namespace according to your own situation.
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