session-context

A session bean needs to interact with the container (get security info, check rollbacks, get a reference to its own EJB object). How does the bean access these container-provided services?

SessionContext is the EJB context specific to session beans. It extends EJBContext and provides getEJBObject() and getEJBLocalObject() methods, which beans use to get a reference to themselves (never use this keyword in EJB).

1. setSessionContext(): Container calls this to inject the context
2. getEJBObject(): Returns reference to the bean’s EJB object (remote)
3. getEJBLocalObject(): Returns reference to the bean’s local EJB object
4. Why not this?: this is the raw bean; clients call via EJB object proxy
5. Usage: Pass self-reference to other beans via getEJBObject()

• Extends EJBContext: Inherits getCallerPrincipal(), setRollbackOnly(), etc.
• Injected by container: Via setSessionContext() callback
• getEJBObject(): For remote interfaces
• getEJBLocalObject(): For local interfaces
• Never use this: Bean must use EJB object for self-reference

• Built from: EJB Context — SessionContext extends EJBContext
• Related: Session Bean — SessionContext is for session beans
• Contrasts with: Entity Context — entity beans have different context
• Related: Why Bean Doesn't Implement Interface — this danger
• Builds into: Business Interface Pattern — context used in pattern

• this danger: Passing this bypasses container services
• Null check: Context may be null before setSessionContext() called
• Runtime only: Context not available during new (only after container injects)
• Method restrictions: Can’t call getEJBObject() in ejbCreate() (EJB object not associated yet)