最近在做一个jena的例子，写入两个本体到mysql中，然后去读取它，成功；
问题是我把写入操作注释掉后，只运行读取的操作，就会出错；
获取的异常信息是
Failure to instantiate DB Driver:MySQL java.sql.SQLException: No suitable driver found for jdbc:mysql://localhost/ontologydb
百思不得其解啊，写入+读取可以运行，不会出现连接驱动错误；但是单独读取，就会报错。。不知道是什么问题。
附源码如下
import java.io.File;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.InputStreamReader;
import java.io.UnsupportedEncodingException;
import com.hp.hpl.jena.db.DBConnection;
import com.hp.hpl.jena.db.IDBConnection;
import com.hp.hpl.jena.ontology.OntModel;
import com.hp.hpl.jena.ontology.OntModelSpec;
import com.hp.hpl.jena.rdf.model.Model;
import com.hp.hpl.jena.rdf.model.ModelFactory;
import com.hp.hpl.jena.rdf.model.ModelMaker;
public class JenaDBOpration {
// path of driver class
public static final String strDriver = "com.mysql.jdbc.Driver";
// The URL of the MySql database
// this can be modified when the server location changes
public static final String strURL = "jdbc:mysql://localhost/ontologydb";
// database user id
public static final String strUser = "root";
// database password
public static final String strPassWord = "nicky";
// database type
public static final String strDB = "MySQL";
public static final String strFilePath1 = "F:\\毕业论文相关\\Ontology开发日志\\本体元数据模型本体\\OntologyMetaDataModel.owl";
public static final String strOntologyName1 = "One";
public static final String strOntologyName2 = "Two";
public static final String strFilePath2 = "F:\\毕业论文相关\\Ontology开发日志\\一维水质模型本体\\1DHDWQM.owl";
public static boolean TestMySQLDriver(String MySQL_Driver) {
boolean result = false;
// 加载数据库驱动类，需要处理异常
try {
Class.forName(MySQL_Driver);
result = true;
} catch (ClassNotFoundException e) {
System.out.println(e.getMessage());
System.out.println("Driver is not available...");
}
return result;
}
public static InputStreamReader ReadFile(String FilePath) {
FileInputStream inputSreamfile = null;
try {
File file = new File(FilePath);
inputSreamfile = new FileInputStream(file);
} catch (FileNotFoundException e) {
e.printStackTrace();
System.out.println("Ontology File is not available...");
}
InputStreamReader in = null;
try {
in = new InputStreamReader(inputSreamfile, "UTF-8");
} catch (UnsupportedEncodingException e) {
e.printStackTrace();
}
return in;
}
// 建立一个到mysql的连接
public static IDBConnection connectDB(String DB_URL, String DB_USER,
String DB_PASSWARD, String DB_NAME) {
return new DBConnection(DB_URL, DB_USER, DB_PASSWARD, DB_NAME);
}
/* 从文件读取本体并将其存入数据库 */
public static boolean createDBModelFromFile(IDBConnection con,
String Ontology_Name, String filePath) {
try {
ModelMaker maker = ModelFactory.createModelRDBMaker(con);
Model base = maker.createModel(Ontology_Name);
base.read(ReadFile(filePath), null);
base.commit();
} catch (Exception E) {
System.out.println(E.getMessage());
}
return true;
}
/* 从数据库中得到已存入本体 */
public static OntModel getModelFromDB(IDBConnection con,
String Ontology_Name) {
ModelMaker maker = ModelFactory.createModelRDBMaker(con);
Model base = maker.getModel(Ontology_Name);
OntModel newmodel = ModelFactory.createOntologyModel(
OntModelSpec.OWL_DL_MEM, base);
return newmodel;
}
public static OntModelSpec getModelSpec(ModelMaker maker) {
OntModelSpec spec = new OntModelSpec(OntModelSpec.OWL_MEM);
spec.setImportModelMaker(maker);
return spec;
}
/**
* @param args
*/
public static void main(String[] args) {
// TODO Auto-generated method stubgetModelgetModel
try {
boolean test = false;
try {
test = JenaDBOpration.TestMySQLDriver(strDriver);
} catch (Exception ex) {
System.out.println(ex.getMessage());
}
if (test) {
try {
IDBConnection idbc = JenaDBOpration.connectDB(strURL,
strUser, strPassWord, strDB);
JenaDBOpration.createDBModelFromFile(idbc,
strOntologyName1, strFilePath1);
JenaDBOpration.createDBModelFromFile(idbc,
strOntologyName2, strFilePath2);
} catch (Exception ex2) {
System.out.println(ex2.getMessage());
}
}
} catch (Exception e) {
System.out.println(e.getMessage());
}
try {
IDBConnection idbc = JenaDBOpration.connectDB(strURL, strUser,
strPassWord, strDB);
ModelMaker mmr = ModelFactory.createModelRDBMaker(idbc);
Model m = mmr.getModel(strOntologyName1);
OntModel ontM = getModelFromDB(idbc, strOntologyName1);
} catch (Exception ex) {
System.out.println(ex.getMessage());
}
}
}
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2010/3/23 16:03:00
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jena对mysql的读取[求助]
