Final answer:
The Session interface in Hibernate is essential for CRUD operations in a Java application, managing the connection and transactions with the database. It maintains a first-level cache, manages transaction boundaries, and synchronizes object states with the database.
Step-by-step explanation:
The Session interface is a fundamental part of the Hibernate framework and plays a critical role in the interaction between the Java application and the database. It acts as a bridge for database operations. Essentially, the Session is responsible for providing the methods to perform CRUD (Create, Read, Update, Delete) operations on the objects that represent your database tables.
A Session begins when it is first created and is connected to the persistent context. Within the boundaries of a Session, it maintains the first-level cache, which ensures that the same database read within a transaction returns the same Java object, thereby reducing the number of read operations on a database. Additionally, the Session can manage transaction boundaries, on a coarse or fine-grained level, and implements the unit of work pattern that allows us to commit or rollback changes as a single transaction.
When working with Hibernate, developers use the Session to get a physical connection with a database, execute queries, fetch results, persist new objects, or update existing ones. The Session also keeps track of the object's state, synchronizing with the database according to the transactional operations applied.