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javaspring-bootconfigurationkafka-consumer-api

Control enabling/disabling Kafka consumers in Spring Boot


I have configured several Kafka consumers in Spring Boot. This is what the kafka.properties looks like (only listing config for one consumer here):

kafka.topics=
bootstrap.servers=
group.id=
enable.auto.commit=
auto.commit.interval.ms=
session.timeout.ms=
schema.registry.url=
auto.offset.reset=
kafka.enabled=

Here is the config:

@Configuration
@PropertySource({"classpath:kafka.properties"})
public class KafkaConsumerConfig {

    @Autowired
    private Environment env;

    @Bean
    public ConsumerFactory<String, String> pindropConsumerFactory() {
        Map<String, Object> dataRiverProps = new HashMap<>();

        dataRiverProps.put(ConsumerConfig.BOOTSTRAP_SERVERS_CONFIG, env.getProperty("bootstrap.servers"));
        dataRiverProps.put(ConsumerConfig.GROUP_ID_CONFIG, env.getProperty("group.id"));
        dataRiverProps.put(ConsumerConfig.ENABLE_AUTO_COMMIT_CONFIG, env.getProperty("enable.auto.commit"));
        dataRiverProps.put(ConsumerConfig.AUTO_COMMIT_INTERVAL_MS_CONFIG, env.getProperty("auto.commit.interval.ms"));
        dataRiverProps.put(ConsumerConfig.SESSION_TIMEOUT_MS_CONFIG, env.getProperty("session.timeout.ms"));

        dataRiverProps.put(ConsumerConfig.KEY_DESERIALIZER_CLASS_CONFIG, StringDeserializer.class.getName());
        dataRiverProps.put(ConsumerConfig.VALUE_DESERIALIZER_CLASS_CONFIG, StringDeserializer.class.getName());
        dataRiverProps.put(ConsumerConfig.AUTO_OFFSET_RESET_CONFIG, env.getProperty("auto.offset.reset"));

        return new DefaultKafkaConsumerFactory<>(dataRiverProps);
    }

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

And this is the consumer:

@Component
public class KafkaConsumer {

    @Autowired
    private MessageProcessor messageProcessor;


    @KafkaListener(topics = "#{'${kafka.topics}'.split(',')}", containerFactory = "kafkaListenerContainerFactory")
    public void consumeJson(String message) {
        // processing message
    }
}

Is there a way for me to use the prop "kafka.enabled" so that I can control the creation or maybe the message retrieval of this consumer? Thanks so much!


Solution

  • You can do it by using property autoStartup (true/false) in consumer like below -

    @KafkaListener(id = "foo", topics = "Topic1", groupId = "group_id",
            containerFactory = "kafkaListenerContainerFactory",autoStartup = "${listen.auto.start:false}")
    public void consume(String message) {
        //System.out.println("Consumed message: " + message);
    }