I have been confused about transaction.rollback. If the Session throws an exception, the transaction must be rolled back and the session must be discarded. A typical transaction should use the following idiom: A persistent instance has a representation in the database, an identifier value and is associated with a Session.ĭetached: Once we close the Hibernate Session, the persistent instance will become a detached instance.Ī Session instance is serializable if its persistent classes are serializable. Persistent: You can make a transient instance persistent by associating it with a Session. Transient: A new instance of a a persistent class which is not associated with a Session and has no representation in the database and no identifier value is considered transient by Hibernate. Instances may exist in one of the following three states at a given point in time: The main function of the Session is to offer create, read and delete operations for instances of mapped entity classes. The session objects should not be kept open for a long time because they are not usually thread safe and they should be created and destroyed them as needed. Persistent objects are saved and retrieved through a Session object. The Session object is lightweight and designed to be instantiated each time an interaction is needed with the database. A Session is used to get a physical connection with a database.

Roll back java update