Spring Cloud Stream - Functional Supplier is not polling

Question

In Spring Cloud Stream, I used the functional model and created a Supplier to generateEvents. As per the documentation , I expect that this supplier will get invoked on a scheduled basis, but that's not happening. It gets invoked once upon bean creation, and never again. I'd appreciate any help in figuring out why.

EventSource.java (Supplier):

@Component
@Slf4j
public class EventSource {

    @Bean
    public Supplier<String> generateEvents() {
        log.debug("creating an event to publish to Kafka");
        return () -> "Hi I'm an event";
    }

}

application.yml:

spring:
  cloud:
    function:
      definition: generateEvents
    stream:
      bindings:
        generateEvents-out-0:
          destination: eventsTopic

I know I'm connecting to Kafka, because the topic eventsTopic gets created upon startup. The Cloud Stream app stays up, but doesn't do anything.

Answer 1

You can follow this code and I hope you solve the problem:

@Configuration
@Slf4j
public class EventSource {

    @Bean
    public Supplier<String> generateEvents() {
        return () -> {
            log.debug("creating an event to publish to Kafka");
            return "Hi I'm an event";
        };
    }
}