To access an application deployed in server, client invokes
-
Session bean method
-
Entity bean method
-
Message driven method
-
Object Bean method
Clients interact with session beans to access application business logic. Session beans serve as the client-facing business interface. Entity beans (in EJB 2.x) are for persistence and not directly invoked by clients. Message-driven beans process asynchronous messages and are also not directly invoked by clients.
To access a deployed application, a client invokes a session bean method. Session beans expose the business logic/use cases of an EJB application to remote or local clients (stateless session beans for reusable operations, stateful for client-specific conversational state). Entity beans (in older EJB 2.x style) represent persistent data/rows in a database and are typically accessed indirectly through session beans (the session bean acts as the facade), not invoked directly by external clients. Message-driven beans respond to asynchronous JMS messages, not direct client method calls. 'Object Bean' isn't a real EJB component type. So the client-facing entry point into deployed EJB business logic is the session bean, making it correct.