com.europabrewing.util.HibernateUtil.java Source code

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Here is the source code for com.europabrewing.util.HibernateUtil.java

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/*
 * Copyright  2013 Jarett Creason
 *
 * This file is part of BrewNinja.
 *
 * BrewNinja 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.
 *
 * BrewNinja 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.
 *
 * You should have received a copy of the GNU General Public License
 * along with BrewNinja in the file named COPYING in the root directory.
 * If not, see <http://www.gnu.org/licenses/>.
 */

package com.europabrewing.util;

import org.hibernate.HibernateException;
import org.hibernate.Query;
import org.hibernate.Session;
import org.hibernate.SessionFactory;
import org.hibernate.cfg.Configuration;
import org.hibernate.metadata.ClassMetadata;
import org.hibernate.service.ServiceRegistry;
import org.hibernate.service.ServiceRegistryBuilder;

import java.util.List;
import java.util.Map;

/**
 * @author jcreason - jcreason@gmail.com
 * @date July 2013
 *
 * Please see the README and/or documentation associated
 */
public class HibernateUtil {

    private static final SessionFactory sessionFactory = buildSessionFactory();

    /**
     * Connect to the database and create a sessionFactory object
     *
     * @return the newly created session factory
     */
    private static SessionFactory buildSessionFactory() {
        try {
            Configuration configuration = new Configuration();
            // avoid slow startup: http://stackoverflow.com/questions/10075081/hibernate-slow-to-acquire-postgres-connection
            //         configuration.setProperty("hibernate.temp.use_jdbc_metadata_defaults", "false");
            configuration.configure();

            ServiceRegistry serviceRegistry = new ServiceRegistryBuilder()
                    .applySettings(configuration.getProperties()).buildServiceRegistry();

            return configuration.buildSessionFactory(serviceRegistry);

        } catch (Throwable ex) {
            System.err.println("Initial SessionFactory creation failed." + ex);
            throw new ExceptionInInitializerError(ex);
        }
    }

    /**
     * Return the SessionFactory object
     *
     * @return SessionFactory
     */
    public static SessionFactory getSessionFactory() {
        return sessionFactory;
    }

    /**
     * Return a newly created Session
     *
     * @return Session
     * @throws org.hibernate.HibernateException
     */
    public static Session getSession() throws HibernateException {
        return getSessionFactory().openSession();
    }

    /**
     * Helper function to have one place to suppress warnings
     *
     * @param q
     * @param <T>
     * @return
     */
    public static <T> List<T> listAndCast(Query q) {
        @SuppressWarnings("unchecked")
        List list = q.list();
        return list;
    }

    /**
     * Print all data that is held in this database
     *
     * @throws org.hibernate.HibernateException
     */
    public static void printAllData() throws HibernateException {
        Session session = getSession();

        try {
            System.out.println("querying all the managed entities...");

            final Map<String, ClassMetadata> metadataMap = session.getSessionFactory().getAllClassMetadata();

            for (String key : metadataMap.keySet()) {
                final ClassMetadata classMetadata = metadataMap.get(key);
                final String entityName = classMetadata.getEntityName();
                final Query query = session.createQuery("from " + entityName);

                System.out.println("executing: " + query.getQueryString());
                for (Object o : query.list()) {
                    System.out.println("  " + o);
                }
            }

        } finally {
            session.close();
        }
    }
}