Spring Core

Exercise: Chat Application (Basic Messaging)

1. Run the ActiveMQ Classic message broker:

   docker run --name activemq -p 8161:8161 -p 61616:61616 -d apache/activemq-classic
   

2. Create a Spring application with the starters spring-boot-starter-activemq and spring-boot-starter-json as dependencies.
3. Define application properties that provide the URL of the ActiveMQ Classic message broker and enable the publish-subscribe domain:

   spring.activemq.broker-url=tcp://localhost:61616
   spring.jms.pub-sub-domain=true
   

4. Implement a publisher and a listener component that allow a user to send text messages to and receive text messages from the topic ChatTopic.
5. Add a property user to the messages that identifies the sender of the message and display it.
6. Define a message selector such that the sender's own messages are not received.