hibernate_bootstrap-hibernate-initialization.java

DatabaseInit.java

package dao;

import org.hibernate.HibernateException;
import org.hibernate.Session;
import org.hibernate.SessionFactory;
import org.hibernate.Transaction;
import org.hibernate.boot.Metadata;
import org.hibernate.boot.MetadataSources;
import org.hibernate.boot.registry.StandardServiceRegistry;
import org.hibernate.boot.registry.StandardServiceRegistryBuilder;

import dao.interfaces.DatabaseInterface;

public class DatabaseInit implements DatabaseInterface {
	
	private StandardServiceRegistry standardServiceRegistry;
	private Metadata metadata;
	private static SessionFactory sessionFactory;
	private Session session;
	private Transaction transaction;
	
	public DatabaseInit() {
		initConnection();
	}

	@Override
	public void initConnection() {
		if (sessionFactory == null) {
			this.standardServiceRegistry = new StandardServiceRegistryBuilder().configure(DatabaseInterface.HIBERNATE_CONFIG).build();
			this.metadata = new MetadataSources(this.standardServiceRegistry).getMetadataBuilder().build();
			sessionFactory = metadata.getSessionFactoryBuilder().build();
		}
	}

	@Override
	public Session openConnection() {
		try {
			if (this.session == null || !this.session.isOpen()) {
				this.session = sessionFactory.openSession();
				this.transaction = session.beginTransaction();
			}
		} catch (HibernateException e) {
			e.printStackTrace();
		}
		return this.session;
	}

	@Override
	public void processConnection() {
		try {
			openConnection();
			this.transaction.commit();
		} catch (HibernateException e) {
			if (this.transaction != null) {
				this.transaction.rollback();
			}
			e.printStackTrace();
		} finally {
			closeConnection();
		}
	}

	@Override
	public void closeConnection() {
		this.session.close();
	}
}

DatabaseInterface.java

package dao.interfaces;

import org.hibernate.Session;

public interface DatabaseInterface {

	String HIBERNATE_CONFIG = "hibernate.cfg.xml";
	
	void initConnection();
	Session openConnection();
	void processConnection();
	void closeConnection();
}