Cannot get a connection as the driver manager is not properly initialized

Пытаюсь получить данные из бд

hibernate.cfg.xml:

<!DOCTYPE hibernate-configuration PUBLIC
    "-//Hibernate/Hibernate Configuration DTD//EN"
    "http://www.hibernate.org/dtd/hibernate-configuration-3.0.dtd">
<hibernate-configuration>
  <session-factory>

      <property name="connection.url">jdbc:mysql://localhost:3306/test?useSSL=false&amp;serverTimezone=UTC</property>
      <property name="connection.username">root</property>
      <property name="connection.password">root</property>

      <property name="show_sql">true</property>
      <property name="hibernate.format_sql">true</property>

      <property name="default_schema">test</property>

      <property name="hibernate.current_session_context_class">thread</property>

      <mapping class="ru.java.hibernate.entity.Groups"/>
      <mapping class="ru.java.hibernate.entity.Students"/>

  </session-factory>
</hibernate-configuration>

HibernateUtil.java:

package ru.java.hibernate;

import org.hibernate.SessionFactory;
import org.hibernate.boot.MetadataSources;
import org.hibernate.boot.registry.StandardServiceRegistry;
import org.hibernate.boot.registry.StandardServiceRegistryBuilder;

public class HibernateUtil {
    public static SessionFactory sessionFactory;

    static {
        final StandardServiceRegistry registry = new StandardServiceRegistryBuilder()
                .configure()
                .build();
        try {
            sessionFactory = new MetadataSources(registry).buildMetadata().buildSessionFactory();
        } catch (Exception ex) {
            StandardServiceRegistryBuilder.destroy(registry);
        }
    }

    public static SessionFactory getSessionFactory() {
        return sessionFactory;
    }
}

GroupsHelper.java:

package ru.java.hibernate;

import org.hibernate.Session;
import org.hibernate.SessionFactory;
import ru.java.hibernate.entity.Groups;

import javax.persistence.Query;
import javax.persistence.criteria.CriteriaBuilder;
import javax.persistence.criteria.CriteriaQuery;
import javax.persistence.criteria.Root;
import java.util.List;

public class GroupsHelper {
    private final SessionFactory sessionFactory;

    public GroupsHelper() { sessionFactory = HibernateUtil.getSessionFactory();}

    public List<Groups> getGroupsList() {
        Session session = sessionFactory.openSession();

        session.get(Groups.class, 1);

        CriteriaBuilder cb = session.getCriteriaBuilder();

        CriteriaQuery<Groups> cq = cb.createQuery(Groups.class);

        Root<Groups> root = cq.from(Groups.class);

        cq.select(root);

        Query query = session.createQuery(cq);

        List<Groups> groupsList = query.getResultList();

        session.close();

        return groupsList;
    }

    public Groups getGroup(String name) { return null;}
}

Start.java:

package ru.java.hibernate;

import org.hibernate.Session;
import ru.java.hibernate.entity.Groups;

public class Start {
    public static void main(String[] args) {
        Session session = HibernateUtil.getSessionFactory().openSession();
        for (Groups groups: new GroupsHelper().getGroupsList()) {
            System.out.println("group=" + groups.getGr_name());
        }
    }
}

при выполнении кода выдает ошибку:

WARN: HHH000342: Could not obtain connection to query metadata
java.lang.IllegalStateException: Cannot get a connection as the driver manager is not properly initialized
    at org.hibernate.engine.jdbc.connections.internal.DriverManagerConnectionProviderImpl.getConnection(DriverManagerConnectionProviderImpl.java:172)
    at org.hibernate.engine.jdbc.env.internal.JdbcEnvironmentInitiator$ConnectionProviderJdbcConnectionAccess.obtainConnection(JdbcEnvironmentInitiator.java:181)
    at org.hibernate.engine.jdbc.env.internal.JdbcEnvironmentInitiator.initiateService(JdbcEnvironmentInitiator.java:68)
    at org.hibernate.engine.jdbc.env.internal.JdbcEnvironmentInitiator.initiateService(JdbcEnvironmentInitiator.java:35)
    at org.hibernate.boot.registry.internal.StandardServiceRegistryImpl.initiateService(StandardServiceRegistryImpl.java:101)
    at org.hibernate.service.internal.AbstractServiceRegistryImpl.createService(AbstractServiceRegistryImpl.java:263)
    at org.hibernate.service.internal.AbstractServiceRegistryImpl.initializeService(AbstractServiceRegistryImpl.java:237)
    at org.hibernate.service.internal.AbstractServiceRegistryImpl.getService(AbstractServiceRegistryImpl.java:214)
    at org.hibernate.engine.jdbc.internal.JdbcServicesImpl.configure(JdbcServicesImpl.java:51)
    at org.hibernate.boot.registry.internal.StandardServiceRegistryImpl.configureService(StandardServiceRegistryImpl.java:107)
    at org.hibernate.service.internal.AbstractServiceRegistryImpl.initializeService(AbstractServiceRegistryImpl.java:246)
    at org.hibernate.service.internal.AbstractServiceRegistryImpl.getService(AbstractServiceRegistryImpl.java:214)
    at org.hibernate.engine.jdbc.connections.internal.BasicConnectionCreator.convertSqlException(BasicConnectionCreator.java:116)
    at org.hibernate.engine.jdbc.connections.internal.DriverConnectionCreator.makeConnection(DriverConnectionCreator.java:41)
    at org.hibernate.engine.jdbc.connections.internal.BasicConnectionCreator.createConnection(BasicConnectionCreator.java:58)
    at org.hibernate.engine.jdbc.connections.internal.DriverManagerConnectionProviderImpl$PooledConnections.addConnections(DriverManagerConnectionProviderImpl.java:409)
    at org.hibernate.engine.jdbc.connections.internal.DriverManagerConnectionProviderImpl$PooledConnections.<init>(DriverManagerConnectionProviderImpl.java:275)
    at org.hibernate.engine.jdbc.connections.internal.DriverManagerConnectionProviderImpl$PooledConnections.<init>(DriverManagerConnectionProviderImpl.java:249)
    at org.hibernate.engine.jdbc.connections.internal.DriverManagerConnectionProviderImpl$PooledConnections$Builder.build(DriverManagerConnectionProviderImpl.java:453)
    at org.hibernate.engine.jdbc.connections.internal.DriverManagerConnectionProviderImpl.buildPool(DriverManagerConnectionProviderImpl.java:98)
    at org.hibernate.engine.jdbc.connections.internal.DriverManagerConnectionProviderImpl.configure(DriverManagerConnectionProviderImpl.java:73)
    at org.hibernate.boot.registry.internal.StandardServiceRegistryImpl.configureService(StandardServiceRegistryImpl.java:107)
    at org.hibernate.service.internal.AbstractServiceRegistryImpl.initializeService(AbstractServiceRegistryImpl.java:246)
    at org.hibernate.service.internal.AbstractServiceRegistryImpl.getService(AbstractServiceRegistryImpl.java:214)
    at org.hibernate.engine.jdbc.env.internal.JdbcEnvironmentInitiator.buildJdbcConnectionAccess(JdbcEnvironmentInitiator.java:146)
    at org.hibernate.engine.jdbc.env.internal.JdbcEnvironmentInitiator.initiateService(JdbcEnvironmentInitiator.java:66)
    at org.hibernate.engine.jdbc.env.internal.JdbcEnvironmentInitiator.initiateService(JdbcEnvironmentInitiator.java:35)
    at org.hibernate.boot.registry.internal.StandardServiceRegistryImpl.initiateService(StandardServiceRegistryImpl.java:101)
    at org.hibernate.service.internal.AbstractServiceRegistryImpl.createService(AbstractServiceRegistryImpl.java:263)
    at org.hibernate.service.internal.AbstractServiceRegistryImpl.initializeService(AbstractServiceRegistryImpl.java:237)
    at org.hibernate.service.internal.AbstractServiceRegistryImpl.getService(AbstractServiceRegistryImpl.java:214)
    at org.hibernate.id.factory.internal.DefaultIdentifierGeneratorFactory.injectServices(DefaultIdentifierGeneratorFactory.java:178)
    at org.hibernate.service.internal.AbstractServiceRegistryImpl.injectDependencies(AbstractServiceRegistryImpl.java:286)
    at org.hibernate.service.internal.AbstractServiceRegistryImpl.initializeService(AbstractServiceRegistryImpl.java:243)
    at org.hibernate.service.internal.AbstractServiceRegistryImpl.getService(AbstractServiceRegistryImpl.java:214)
    at org.hibernate.boot.internal.InFlightMetadataCollectorImpl.<init>(InFlightMetadataCollectorImpl.java:175)
    at org.hibernate.boot.model.process.spi.MetadataBuildingProcess.complete(MetadataBuildingProcess.java:127)
    at org.hibernate.boot.model.process.spi.MetadataBuildingProcess.build(MetadataBuildingProcess.java:86)
    at org.hibernate.boot.internal.MetadataBuilderImpl.build(MetadataBuilderImpl.java:479)
    at org.hibernate.boot.internal.MetadataBuilderImpl.build(MetadataBuilderImpl.java:85)
    at org.hibernate.boot.MetadataSources.buildMetadata(MetadataSources.java:202)
    at ru.java.hibernate.HibernateUtil.<clinit>(HibernateUtil.java:16)
    at ru.java.hibernate.Start.main(Start.java:8)

Помогите, пожалуйста. Сильно не пинайте, я только начал работать с Hibernate и не понимаю, в чем может быть ошибка