package main;

import org.hibernate.Session;

import dao.Autor;
import dao.Book;
import dao.HibernateUtil;

public class Main {
	public static void main(String[] args) {
		System.out.println("Start Main V");
		HibernateUtil.recreateDatabase(); // ПЕРЕСОЗДАЁТ ТАБЛИЧКИ В БД !!!

		Session session = HibernateUtil.beginTransaction(); // автостарт сессии -
																												// current_session_context_class
		try {
			System.out.println("Создать класс-запись в БД");
			Book b = new Book();
			b.setName("ВойнаИмир");
			Autor a = new Autor();
			a.setName("Иванов");
			b.addAutor(a);
			session.saveOrUpdate(b);
			// session.update(a);
			// session.flush();
			System.out.println("Сохранили в БД класс без коммита");
		} finally {
			HibernateUtil.commitTransaction();
			System.out.println("Коммит прошёл. Всё");
		}
	}
}

package dao;

import org.hibernate.Session;
import org.hibernate.SessionFactory;
import org.hibernate.cfg.AnnotationConfiguration;
import org.hibernate.cfg.Configuration;
import org.hibernate.tool.hbm2ddl.SchemaExport;

public class HibernateUtil {
	//конфиг-файл лежит в папке bin - hibernate.cfg.xml
	private static SessionFactory factory;

	public static Configuration getInitializedConfiguration() {
		AnnotationConfiguration config = new AnnotationConfiguration();
		/* add all of your JPA annotated classes here!!! */
		config.addAnnotatedClass(Customer.class);
		config.addAnnotatedClass(ObjList.class);
		config.configure();
		return config;
	}

	public static Session getSession() {
		if (factory == null) {
			Configuration config = HibernateUtil.getInitializedConfiguration();
			factory = config.buildSessionFactory();
		}
		Session hibernateSession = factory.getCurrentSession();
		return hibernateSession;
	}

	public static void closeSession() {
		HibernateUtil.getSession().close();
	}

	public static void recreateDatabase() {
		Configuration config;
		config = HibernateUtil.getInitializedConfiguration();
		new SchemaExport(config).create(true, true);
	}

	public static Session beginTransaction() {
		Session hibernateSession;
		hibernateSession = HibernateUtil.getSession();
		hibernateSession.beginTransaction();
		return hibernateSession;
	}

	public static void commitTransaction() {
		HibernateUtil.getSession().getTransaction().commit();
	}

	public static void rollbackTransaction() {
		HibernateUtil.getSession().getTransaction().rollback();
	}

	public static void main(String args[]) {
		HibernateUtil.recreateDatabase();
	}

}