Learning Spring Boot 2.0 - Second Edition

Broadcasting saved comments

To consume messages sent via Spring Cloud Stream, the chat application needs its own CommentService:

    @Service 
    @EnableBinding(Sink.class) 
    public class CommentService implements WebSocketHandler { 
 
      private final static Logger log = 
        LoggerFactory.getLogger(CommentService.class); 
        ... 
    } 

The preceding code can be described as follows:

• @Service marks this as a Spring bean, picked up automatically when the chat microservice starts
• @EnableBinding(Sink.class) shows this to be a receiver for Spring Cloud Stream messages
• Our service implements WebSocketHandler, a WebFlux interface that comes with a handle(WebSocketSession) method (which we'll use shortly)
• An Slf4j Logger is used to print out traffic passing through

This ...