How to create Java based Hibernate Configurations

Introduction

In this tutorial we will discuss how to create Java based Hibernate configurations. In Java based configuration we don’t need to create any XML or properties file for putting Hibernate configuration.

We will put Hibernate configuration as well SessionFactory using Java based configuration. To make everything clarified we will create both XML and Java based configuration so that it would be easy to understand.

Prerequisites

Hibernate 5.4.11, Java 8

Hibernate Configurations

Let’s say we have the below hibernate configurations in XML file (hibernate.cfg.xml).

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE hibernate-configuration PUBLIC "-//Hibernate/Hibernate Configuration DTD 3.0//EN" "http://hibernate.sourceforge.net/hibernate-configuration-3.0.dtd">
<hibernate-configuration>
	<session-factory>
		<property name="connection.url">jdbc:mysql://localhost:3306/roytuts</property>
		<property name="connection.username">root</property>
		<property name="connection.password">root</property>
		<property name="connection.driver_class">com.mysql.cj.jdbc.Driver</property>
		<property name="dialect">org.hibernate.dialect.MySQLDialect</property>
		<property name="hibernate.hbm2ddl.auto">update</property>
		<property name="hibernate.current_session_context_class">thread</property>
		<property name="hibernate.query.factory_class">org.hibernate.hql.internal.classic.ClassicQueryTranslatorFactory</property>
		<property name="hibernate.show_sql">true</property>
		<property name="hibernate.format_sql">true</property>
		<mapping class="com.roytuts.hibernate.domain.model.Item" />
	</session-factory>
</hibernate-configuration>

The equivalent configurations in Java will be as shown below:

Properties settings = new Properties();

settings.put(Environment.DRIVER, "com.mysql.cj.jdbc.Driver");
settings.put(Environment.URL, "jdbc:mysql://localhost:3306/roytuts");
settings.put(Environment.USER, "root");
settings.put(Environment.PASS, "root");
settings.put(Environment.DIALECT, "org.hibernate.dialect.MySQLDialect");
settings.put(Environment.SHOW_SQL, "true");
settings.put(Environment.FORMAT_SQL, "true");
settings.put(Environment.CURRENT_SESSION_CONTEXT_CLASS, "thread");
settings.put(Environment.HBM2DDL_AUTO, "update"); // or create
settings.put(Environment.QUERY_TRANSLATOR, "org.hibernate.hql.internal.classic.ClassicQueryTranslatorFactory");

Configuration configuration = new Configuration();

configuration.setProperties(settings);
configuration.addAnnotatedClass(Item.class);

There are more available properties in Hibernate and you can use them if you need.

Build SessionFactory

Now we will build the SessionFactory from the above configurations.

try {
	Configuration configuration = configuration();
	ServiceRegistry serviceRegistry = new StandardServiceRegistryBuilder()
			.applySettings(configuration.getProperties()).build();

	SessionFactory sessionFactory = configuration.buildSessionFactory(serviceRegistry);
} catch (Exception e) {
	e.printStackTrace();
}

The complete source code for Java based hibernate configurations and building SessionFactory is given below:

import java.util.Properties;

import org.hibernate.SessionFactory;
import org.hibernate.boot.registry.StandardServiceRegistryBuilder;
import org.hibernate.cfg.Configuration;
import org.hibernate.cfg.Environment;
import org.hibernate.service.ServiceRegistry;

import com.roytuts.hibernate.criteria.api.entity.Item;

public class HibernateUtils {

	private static SessionFactory sessionFactory;

	public static SessionFactory getSessionFactory() {

		if (sessionFactory == null) {
			try {
				Configuration configuration = configuration();
				ServiceRegistry serviceRegistry = new StandardServiceRegistryBuilder()
						.applySettings(configuration.getProperties()).build();

				sessionFactory = configuration.buildSessionFactory(serviceRegistry);
			} catch (Exception e) {
				e.printStackTrace();
			}
		}

		return sessionFactory;
	}

	private static Configuration configuration() {
		Properties settings = new Properties();

		settings.put(Environment.DRIVER, "com.mysql.cj.jdbc.Driver");
		settings.put(Environment.URL, "jdbc:mysql://localhost:3306/roytuts");
		settings.put(Environment.USER, "root");
		settings.put(Environment.PASS, "root");
		settings.put(Environment.DIALECT, "org.hibernate.dialect.MySQLDialect");
		settings.put(Environment.SHOW_SQL, "true");
		settings.put(Environment.FORMAT_SQL, "true");
		settings.put(Environment.CURRENT_SESSION_CONTEXT_CLASS, "thread");
		settings.put(Environment.HBM2DDL_AUTO, "update"); // or create
		settings.put(Environment.QUERY_TRANSLATOR, "org.hibernate.hql.internal.classic.ClassicQueryTranslatorFactory");

		Configuration configuration = new Configuration();

		configuration.setProperties(settings);
		configuration.addAnnotatedClass(Item.class);

		return configuration;
	}

}

Thanks for reading.