I would like to create a consumer inside a Spring MVC web app. Basically, I'd like the web app to listen to some topics on Kafka and take some action based on the received messages.

All the examples I've seen so far are using either a standalone app with an infinite loop (using plain java) or inside a unit test (using spring):

@Autowired
private Listener listener;

@Autowired
private KafkaTemplate<Integer, String> template;

@Test
public void testSimple() throws Exception {
    template.send("annotated1", 0, "foo");
    template.flush();
    assertTrue(this.listener.latch1.await(10, TimeUnit.SECONDS));
}

@Configuration
@EnableKafka
public class Config {

@Bean
ConcurrentKafkaListenerContainerFactory<Integer, String>
                    kafkaListenerContainerFactory() {
    ConcurrentKafkaListenerContainerFactory<Integer, String> factory =
                            new ConcurrentKafkaListenerContainerFactory<>();
    factory.setConsumerFactory(consumerFactory());
    return factory;
}

@Bean
public ConsumerFactory<Integer, String> consumerFactory() {
    return new DefaultKafkaConsumerFactory<>(consumerConfigs());
}

@Bean
public Map<String, Object> consumerConfigs() {
    Map<String, Object> props = new HashMap<>();
    props.put(ConsumerConfig.BOOTSTRAP_SERVERS_CONFIG, embeddedKafka.getBrokersAsString());
    ...
    return props;
}

@Bean
public Listener listener() {
    return new Listener();
}

@Bean
public ProducerFactory<Integer, String> producerFactory() {
    return new DefaultKafkaProducerFactory<>(producerConfigs());
}

@Bean
public Map<String, Object> producerConfigs() {
    Map<String, Object> props = new HashMap<>();
    props.put(ProducerConfig.BOOTSTRAP_SERVERS_CONFIG, embeddedKafka.getBrokersAsString());
    ...
    return props;
}

@Bean
public KafkaTemplate<Integer, String> kafkaTemplate() {
    return new KafkaTemplate<Integer, String>(producerFactory());
}

}
public class Listener {

    private final CountDownLatch latch1 = new CountDownLatch(1);

    @KafkaListener(id = "foo", topics = "annotated1")
        public void listen1(String foo) {
            this.latch1.countDown();
     }

}

What would be the best place to create the listener? Should I put it there:

@SpringBootApplication
public class Application {

@Autowired
private Listener listener;

    public static void main(String[] args) {
        SpringApplication.run(Application.class, args);
    }

}