- The client’s view
- Fundamentals of the EJB architecture
- Types of EJB
- Distributed and local EJB semantics
- Anatomy of an EJB
- Principle of operation: session and entity EJBs
- Principle of operation: message-driven EJBs
- The EJB container and its proxies
- Overview of the EJB API
- EJB rules, standards and limitations
- Assembly and deployment
3.7 Principle of operation: message-driven EJBs
Figure 3.7 shows the basic principle of operation of a message-driven EJB.
Figure 3.7 . Basic principle of operation of a message-driven EJB.
The EJB container initializes a pool of instances of the EJB’s implementation class.
The client looks up the queue or topic to which the desired EJB is listening.
The client posts messages to this queue or topic.
The messaging service supplies the messages to the EJB container.
The container calls the implementation’s onMessage() method.