9.4 Summary

• Asynchronous messaging provides a layer of indirection between communicating applications, which allows for looser coupling and greater scalability.
• Spring supports asynchronous messaging with JMS, RabbitMQ, or Apache Kafka.
• Applications can use template-based clients (JmsTemplate, RabbitTemplate, or KafkaTemplate) to send messages via a message broker.
• Receiving applications can consume messages in a pull-based model using the same template-based clients.
• Messages can also be pushed to consumers by applying message listener annotations (@JmsListener, @RabbitListener, or @KafkaListener) to bean methods.