Overview Topics

• Revise Hibernate (with code walk through)
• SessionFactory API
  • openSession vs getCurrentSession
• Entity state transitions
  • Transient, persistent, detached, removed
• CRUD operations
• JPQL (Java Persistence Query Language)

Learning Objectives

0. Save User Details (already done)

• Input: User details
• Output: A status message

1. Get User Details by ID

• Input: User ID
• Output: Null or actual user details

Session API for Entity Retrieval by ID

public <T> T get(Class<T> class, Object id) throws HibernateException

• T: Type of the entity (POJO)
• Returns:
  • null in case of invalid ID
  • OR PERSISTENT entity reference
• Note: In earlier versions (till Hibernate 5.x), ID property was required to be Serializable

2. Get All Users

• Output: Display all user details