-- 作者：hrballen
-- 发布时间：8/4/2008 11:04:00 AM
-- jena规则推理时遇到的问题
我是一个初学者，在进行jena规则推理时，遇到些问题，就是推理时规则的编写，还有推理的步骤。请高手指点一下，下面代码哪里有问题？在编写规则时，rule1:(?x http://www.owl-ontologies.com/Animal.owl#111111?y，其中的111111指的是在编写本体时的ObjectPropertyma吗？在输出查询结果时，
Zoo | Herbivore 下面是空的，不知他应该是实例，还是什么？请高手细致地讲一下 import java.util.Iterator; import com.hp.hpl.jena.db.DBConnection;
import com.hp.hpl.jena.db.IDBConnection;
import com.hp.hpl.jena.ontology.OntClass;
import com.hp.hpl.jena.ontology.OntModel;
import com.hp.hpl.jena.ontology.OntModelSpec;
import com.hp.hpl.jena.query.Query;
import com.hp.hpl.jena.query.QueryExecution;
import com.hp.hpl.jena.query.QueryExecutionFactory;
import com.hp.hpl.jena.query.QueryFactory;
import com.hp.hpl.jena.query.ResultSet;
import com.hp.hpl.jena.query.ResultSetFormatter;
import com.hp.hpl.jena.rdf.model.InfModel;
import com.hp.hpl.jena.rdf.model.Model;
import com.hp.hpl.jena.rdf.model.ModelFactory;
import com.hp.hpl.jena.rdf.model.ModelMaker;
import com.hp.hpl.jena.reasoner.Reasoner;
import com.hp.hpl.jena.reasoner.rulesys.GenericRuleReasoner;
import com.hp.hpl.jena.reasoner.rulesys.Rule; public class sparqltuili{
public static final String strDriver = "com.mysql.jdbc.Driver"; // path of driver class
public static final String strURL = "jdbc:mysql://localhost/protege_db"; // URL of database
public static final String strUser = "root"; // database user id
public static final String strPassWord = ""; // database password
public static final String strDB = "MySQL"; // database type
public static void main(String[] args){
try{
// 创建一个数据库连接
IDBConnection con = new DBConnection ( strURL, strUser, strPassWord, strDB );
// 加载数据库驱动类，需要处理异常
try{
System.out.println(strDriver);
Class.forName(strDriver);
}catch(ClassNotFoundException e) {
System.out.println("ClassNotFoundException, Driver is not available...");
}
String filePath = "file:C:\\Program Files\\Protege_3.1\\Animal.owl";
sparqltuili.createDBModelFromFile(con, "1protege_db",filePath);
OntModel model = sparqltuili.getModelFromDB(con, "1protege_db");
sparqltuili.simpleReadOntology(model);
String rule = "[rule1:(?x http://www.owl-ontologies.com/Animal.owl#Belonging ?y) " +
"->(?y http://www.owl-ontologies.com/Animal.owl#Belonged ?x)]";
/*查询语句*/
String queryString = "PREFIX Animal:<http://www.owl-ontologies.com/Animal.owl#> " +
"SELECT ?Zoo ?Herbivore " +
"WHERE { ?Zoo Animal:Belonged ?Herbivore} ";
/*创建推理机*/
Reasoner reasoner2 = new GenericRuleReasoner(Rule.parseRules(rule));
InfModel inf = ModelFactory.createInfModel(reasoner2, model);
Query query = QueryFactory.create(queryString);
QueryExecution qe = QueryExecutionFactory.create(query, inf);
ResultSet results = qe.execSelect();
/*打印结果*/
ResultSetFormatter.out(System.out, results, query);
qe.close();
}catch(Exception e){e.printStackTrace();}}
/* 从文件读取本体并将其存入数据库 */
public static OntModel createDBModelFromFile(IDBConnection con, String name,
String filePath) {
ModelMaker maker = ModelFactory.createModelRDBMaker(con);
Model base = maker.createModel(name);
OntModel newmodel = ModelFactory.createOntologyModel(
getModelSpec(maker), base);
newmodel.read(filePath);
return newmodel;
}
/* 从数据库中得到已存入本体 */
public static OntModel getModelFromDB(IDBConnection con, String name) {
ModelMaker maker = ModelFactory.createModelRDBMaker(con);
Model base = maker.getModel(name);
OntModel newmodel = ModelFactory.createOntologyModel(
getModelSpec(maker), base);
return newmodel;
}
public static OntModelSpec getModelSpec(ModelMaker maker) {
OntModelSpec spec = new OntModelSpec(OntModelSpec.OWL_MEM);
spec.setImportModelMaker(maker);
return spec;
}
/* 简单读取本体中的各个class */
public static void simpleReadOntology(OntModel model) {
for (Iterator i = model.listClasses(); i.hasNext();) {
OntClass c = (OntClass) i.next();
System.out.println(c.getLocalName());
}
}
}
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