I'm trying to retrieve data from a MySQL database through Hibernate, but I'm stuck with this error:
Failed to create sessionFactory object.org.hibernate.service.classloading.spi.ClassLoadingException: Specified JDBC Driver com.mysql.jdbc.Driver could not be loaded
java.lang.ClassNotFoundException: Could not load requested class : com.mysql.jdbc.Driver
[...]
I use a class called DAOFactory to get the hibernate session:
public class DAOFactory {
private static boolean isInstance = false;
private static SessionFactory sessionFactory;
private static ServiceRegistry serviceRegistry;
private static Session session;
private DAOFactory() throws ExceptionInInitializerError{
if( !isInstance ) {
try {
Configuration cfg = new Configuration().configure();
serviceRegistry = new ServiceRegistryBuilder().applySettings(cfg.getProperties())
.buildServiceRegistry();
sessionFactory = cfg.buildSessionFactory(serviceRegistry);
} catch (Throwable ex) {
System.err.println("Failed to create sessionFactory object."+ ex);
throw new ExceptionInInitializerError(ex);
}
session = sessionFactory.openSession();
isInstance = true ;
}
}
public static DAOFactory getInstance() {
return new DAOFactory() ;
}
public Session getSession() {
return session ;
}
}
hibernate.cfg.xml:
<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE hibernate-configuration PUBLIC "-//Hibernate/Hibernate Configuration DTD 3.0//EN"
"http://www.hibernate.org/dtd/hibernate-configuration-3.0.dtd">
<hibernate-configuration>
<session-factory name="">
<property name="connection.driver_class">com.mysql.jdbc.Driver</property>
<property name="connection.url">jdbc:mysql://localhost:3306/enigma</property>
<property name="connection.username">root</property>
<property name="connection.password"></property>
<property name="dialect">org.hibernate.dialect.MySQLDialect</property>
<property name="connection.pool_size">1</property>
<property name="current_session_context_class">thread</property>
<property name="cache.provider_class">org.hibernate.cache.NoCacheProvider</property>
<property name="show_sql">true</property>
<property name="hbm2ddl.auto">update</property>
</session-factory>
</hibernate-configuration>
And mysql-connector-java-5.1.26-bin.jar
is already in the classpath:
Does anyone see what I'm missing ?
You need to add the downloaded Java MySQL Connector JAR in client project's classpath . To do this, right click on your Java Project (JDBCMySQLSample) -> Properties -> Buildpath -> Libraries -> Add External JAR and select “mysql-connector-java-5.1. 14-bin. jar” JAR file.
JDBC (Java Database Connectivity) is a programming interface that lets Java applications access a relational database. SuperCHANNEL needs a JDBC driver so that it can access the relational database system (e.g. SQL Server, Oracle, etc) where your source data is stored.
Thanks to Reimeus for the answer. mysql-connector-java-5.1.26-bin.jar
needs to be in the runtime classpath.
Run -> Run Configurations... -> Classpath -> Add external JAR.
Clean everything, try again, and the Exception is gone.
For those who use Maven: add the following dependency in pom.xml.
<dependency>
<groupId>mysql</groupId>
<artifactId>mysql-connector-java</artifactId>
<version>8.0.17</version>
</dependency>
or choose another version from here.
Then you can get the artifact using:
mvn dependency:resolve
(if you don't use the IDE).
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