Overview of Hibernate

Hibernate makes use of persistent objects commonly called as POJO (POJO = "Plain Old Java Object".) along with XML mapping documents for persisting objects to the database layer. The term POJO refers to a normal Java objects that does not serve any other special role or implement any special interfaces of any of the Java frameworks (EJB, JDBC, DAO, JDO, etc...).
Rather than utilize byte code processing or code generation, Hibernate uses runtime reflection to determine the persistent properties of a class. The objects to be persisted are defined in a mapping document, which serves to describe the persistent fields and associations, as well as any subclasses or proxies of the persistent object. The mapping documents are compiled at application startup time and provide the framework with necessary information for a class. Additionally, they are used in support operations, such as generating the database schema or creating stub Java source files.

sessionFactory = new
Configuration().configure().buildSessionFactory();
Session session = sessionFactory.openSession();
Transaction tx = session.beginTransaction();
Customer newCustomer = new Customer();

newCustomer.setName("New Customer");

newCustomer.setAddress("Address of New Customer");

newCustomer.setEmailId("NewCustomer@NewCustomer.com");
session.save(newCustomer);
tx.commit();
session.close();

First step is hibernate application is to retrieve Hibernate Session; Hibernate Session is the main runtime interface between a Java application and Hibernate. SessionFactory allows applications to create hibernate session by reading hibernate configurations file hibernate.cfg.xml. After specifying transaction boundaries, application can make use of persistent java objects and use session for persisting to the databases.