一些基本配置和信息参见前一篇《运用jena将外部本体持久化到mysql》。运用jena将持久化到mysql的本体导出来并进行简单推理的代码如下： 

import com.hp.hpl.jena.db.DBConnection; 
import com.hp.hpl.jena.db.IDBConnection; 
import com.hp.hpl.jena.db.RDFRDBException; 
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 ReadFMySQL { 
public static final String strDriver = "com.mysql.jdbc.Driver"; // path of driver class 
public static final String strURL = "jdbc:mysql://localhost:3306/jena"; // URL of database 
public static final String strUser = "root"; // database user id 
public static final String strPassWord = "root"; // 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 conn = new DBConnection(strURL, strUser, strPassWord,strDB); 
// 加载数据库驱动类，需要处理异常 
try { 
Class.forName(strDriver); 
} catch (ClassNotFoundException e) { 
System.out 
.println("ClassNotFoundException, Driver is not available..."); 
} 
// 使用数据库连接参数创建一个模型制造器 
ModelMaker maker = ModelFactory.createModelRDBMaker(conn); 
// 创建一个默认模型，命名为 MyOntology 
Model defModel = maker.createModel("MyOntology"); 
// OntModel a=maker.createDefaultModel(); 
// OntModel wnOntology = ModelFactory.createOntologyModel(); 
OntModel onto=ModelFactory.createOntologyModel(OntModelSpec.OWL_DL_MEM_RDFS_INF, defModel); 
Model instances=ModelFactory.createDefaultModel(); 
instances.add(defModel); 
/*设置规则*/ 
String rule = "[rule1:(?x http://www.owl-ontologie.com/Expert.owl#research ?y) " + 
"(?y http://www.owl-ontologies.com/Expert.owl#associate ?z) " + 
"->(?x http://www.owl-ontologies.com/Expert.owl#familiar_with ?z)]"; 

/*查询SPARQL语句*/ 
String queryString = "PREFIX Expert:<http://www.owl-ontologies.com/Expert.owl#> " + 
"SELECT ?expert ?subject " + 
"WHERE {?expert Expert:familiar_with ?subject} "; 

/*创建推理机*/ 
Reasoner reasoner2 = new GenericRuleReasoner(Rule.parseRules(rule)); 
System.out.println("creating reasoner......"); 
// 推理机与本体模型绑定 
InfModel inf = ModelFactory.createInfModel(reasoner2, instances); 
System.out.println("binding......"); 
// 构造查询 
Query query = QueryFactory.create(queryString); 
System.out.println("querying......"); 
// 执行查询 
QueryExecution qe = QueryExecutionFactory.create(query, inf); 
// 获取结果 
ResultSet results = qe.execSelect(); 
/*打印结果*/ 
ResultSetFormatter.out(System.out, results, query); 
qe.close(); 

System.out.print("over,sir!"); 

} catch (RDFRDBException e) { 
System.out.println("Exceptions occur..."); 
} 

} 
}

[1] String rule = "[rule1:(?x http://www.owl-ontologie.com/Expert.owl#research ?y) " + 
"(?y http://www.owl-ontologies.com/Expert.owl#associate ?z) " + 
"->(?x http://www.owl-ontologies.com/Expert.owl#familiar_with ?z)]"; 

经过我的测试，这些URI随便改都可以，不知道是什么原因 

[2] String queryString = "PREFIX Expert:<http://www.owl-ontologies.com/Expert.owl#> " + 
"SELECT ?expert ?subject " + 
"WHERE {?expert Expert:familiar_with ?subject} "; 

这里的URI一改，运行结果就有变化，再试试看[可能是PREFIX要和OWL文件中的声名：xmlns 和xmlns:base要一致]