Java.Hibernate.Beginner.Does sessionFactory lives in sessionManager ?

Not quite — there isn’t actually a Hibernate class called SessionManager. But let’s unpack the correct relationship between these components:

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🔹 SessionFactory:

• The SessionFactory is the central, heavyweight Hibernate component.
• It’s created once per application (singleton) and is thread-safe.
• It holds configuration (database settings, mappings, cache regions) and produces individual Session instances as needed.
• Think of it as a factory: its job is to create and manage Sessions, but it doesn’t itself contain or manage active sessions.

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🔹 Session:

• Each Session is a lightweight, per-unit-of-work object created by the SessionFactory.
• The Session manages:
  • Database connections,
  • First-level cache,
  • Transaction boundaries.

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🔹 What about Spring’s Transaction Manager?

• In Spring, you typically don’t work with SessionFactory and Session directly.
• Instead, Spring uses a transaction manager like HibernateTransactionManager or JpaTransactionManager to:
  • Acquire a Session from the SessionFactory when a transaction begins,
  • Bind that Session to the current thread,
  • Commit or rollback the transaction,
  • Close the Session automatically.
• So you could think of Spring’s transaction manager as the “manager” coordinating SessionFactory and Sessions, but there’s no Hibernate class literally called SessionManager.

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🔹 Diagram of relationships:

[SessionFactory] 
     ↳ creates → [Session] ← managed by → [Spring Transaction Manager (@Transactional)]

✅ Key takeaway:

• SessionFactory doesn’t “live” inside any SessionManager.
• Instead, SessionFactory exists independently and produces Session instances.
• In Spring apps, the transaction manager orchestrates the lifecycle of sessions created by the SessionFactory.