Java tutorial
/* * Copyright (c) 2010-2012 Thiago T. S * * This file is part of cloudoutput. * * cloudoutput is free software: you can redistribute it and/or modify * it under the terms of the GNU General Public License as published by * the Free Software Foundation, either version 3 of the License, or * (at your option) any later version. * * cloudoutput is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * GNU General Public License for more details. * * For more information about your rights as a user of cloudoutput, * refer to the LICENSE file or see <http://www.gnu.org/licenses/>. */ package cloudoutput.database; import org.hibernate.Session; import org.hibernate.SessionFactory; import org.hibernate.cfg.Configuration; /** * Provides utility operations related to the Hibernate framework. * * @author Thiago T. S * @since 1.0 */ public class HibernateUtil { /** A session factory. It provides database sessions to DAO methods. */ private static SessionFactory sessionFactory; /** The current active database. */ private static String activeDatabase; /** * Provides an opened database session. * * @see #sessionFactory * @return a database session. * @since 1.0 */ public static Session getSession() { return sessionFactory.openSession(); } /** * Closes a given database session. * * @param session the session to be closed. * @since 1.0 */ public static void closeSession(Session session) { if (session != null) { session.clear(); session.close(); } } /** * Closes the session factory. * * @see #sessionFactory * @since 1.0 */ public static void shutDown() { sessionFactory.close(); } /** * Gets the active database. * It consists of the name of the cloudoutput Environment (.cre) file * without its extension. * * @see #activeDatabase * @since 1.0 */ public static String getActiveDatabase() { return activeDatabase.replace(".cre", ""); } /** * Sets the active database. * It changes the active database and builds a new session factory for it. * * @param aActiveDatabase the name of the file that contains the new database. * @see #activeDatabase * @since 1.0 */ public static void setActiveDatabase(String aActiveDatabase) { if (sessionFactory != null) sessionFactory.close(); activeDatabase = aActiveDatabase; Configuration cfg = new Configuration(); cfg.configure(); System.setProperty("hibernate.connection.driver_class", "org.sqlite.JDBC"); System.setProperty("hibernate.dialect", "cloudoutput.database.SQLiteDialect"); System.setProperty("hibernate.connection.url", "jdbc:sqlite:db/" + activeDatabase); cfg.setProperties(System.getProperties()); sessionFactory = cfg.buildSessionFactory(); } }