1- Configuration class – includes 2 things
(i)Database connection- Using either .cfg or .properties file
(ii)mapping – connection between java classes to database tables using either .hbm files or annotations
- Object of Session is created each time when any operation is required.
- Session objects are used to create physical connection with database.
- Session is thread-safe.
- Session holds a mandatory (first-level) cache of saved java objects in database.
- Session wraps JDBC connection for Transaction.
- Object of SessionFactory should be created only once per database.
- SessionFactory is used to create session objects.
4- Transaction Interface-
- Transaction represents unit of work with database.
- Transaction is associated with session.
- Query is used to create manual queries.
- Criteria is used to apply conditions on the result set.