Problems adding multiple KafkaListenerContainerFactories

Question

Hi I'm currently dabbling in Spring Kafka and succeeded in adding a single KafkaListenerContainerFactory to my listener. Now I'd like to add multiple KafkaListenerContainerFactorys (One for a topic that will have messages in json, another one for strings). See code below:

@EnableKafka
@Configuration
public class KafkaConsumersConfig {

    private final KafkaConfiguration kafkaConfiguration;

    @Autowired
    public KafkaConsumersConfig(KafkaConfiguration kafkaConfiguration) {
        this.kafkaConfiguration = kafkaConfiguration;
    }

    @Bean
    public KafkaListenerContainerFactory<?> kafkaJsonListenerContainerFactory(){
        ConcurrentKafkaListenerContainerFactory<String,Record> factory = new ConcurrentKafkaListenerContainerFactory<>();
        factory.setConsumerFactory(jsonConsumerFactory());
        factory.setConcurrency(3);
        factory.setAutoStartup(true);
        return factory;
    }

    @Bean
    public ConsumerFactory<String,Record> jsonConsumerFactory(){
        JsonDeserializer<Record> jsonDeserializer = new JsonDeserializer<>(Record.class);
        return new DefaultKafkaConsumerFactory<>(jsonConsumerConfigs(),new StringDeserializer(), jsonDeserializer);
    }

    @Bean
    public Map<String,Object> jsonConsumerConfigs(){
        Map<String,Object> propsMap = new HashMap<>();
        propsMap.put(ConsumerConfig.BOOTSTRAP_SERVERS_CONFIG,  kafkaConfiguration.getBrokerAddress());
        propsMap.put(ConsumerConfig.GROUP_ID_CONFIG, kafkaConfiguration.getJsonGroupId());
        propsMap.put(ConsumerConfig.ENABLE_AUTO_COMMIT_CONFIG, kafkaConfiguration.getAutoCommit());
        propsMap.put(ConsumerConfig.AUTO_COMMIT_INTERVAL_MS_CONFIG, kafkaConfiguration.getAutoCommitInterval());
        propsMap.put(ConsumerConfig.SESSION_TIMEOUT_MS_CONFIG, kafkaConfiguration.getSessionTimeout());
        return propsMap;
    }
    @Bean
    public KafkaListenerContainerFactory<?> kafkaFileListenerContainerFactory(){
        ConcurrentKafkaListenerContainerFactory<String,String> factory = new ConcurrentKafkaListenerContainerFactory<>();
        factory.setConsumerFactory(fileConsumerFactory());
        factory.setConcurrency(3);
        factory.setAutoStartup(true);
        return factory;
    }

    @Bean
    public ConsumerFactory<String,String> fileConsumerFactory(){
        return new DefaultKafkaConsumerFactory<>(fileConsumerConfigs());
    }

    @Bean
    public Map<String,Object> fileConsumerConfigs(){
        Map<String,Object> propsMap = new HashMap<>();
        propsMap.put(ConsumerConfig.BOOTSTRAP_SERVERS_CONFIG,  kafkaConfiguration.getBrokerAddress());
        propsMap.put(ConsumerConfig.GROUP_ID_CONFIG, kafkaConfiguration.getFileGroupId());
        propsMap.put(ConsumerConfig.ENABLE_AUTO_COMMIT_CONFIG, kafkaConfiguration.getAutoCommit());
        propsMap.put(ConsumerConfig.AUTO_COMMIT_INTERVAL_MS_CONFIG, kafkaConfiguration.getAutoCommitInterval());
        propsMap.put(ConsumerConfig.SESSION_TIMEOUT_MS_CONFIG, kafkaConfiguration.getSessionTimeout());
        return propsMap;
    }
}

Running this gives me the following error:

Description:

Parameter 1 of method kafkaListenerContainerFactory in org.springframework.boot.autoconfigure.kafka.KafkaAnnotationDrivenConfiguration required a bean of type 'org.springframework.kafka.core.ConsumerFactory' that could not be found.
    - Bean method 'kafkaConsumerFactory' in 'KafkaAutoConfiguration' not loaded because @ConditionalOnMissingBean (types: org.springframework.kafka.core.ConsumerFactory; SearchStrategy: all) found beans 'jsonConsumerFactory', 'fileConsumerFactory'


Action:

Consider revisiting the conditions above or defining a bean of type 'org.springframework.kafka.core.ConsumerFactory' in your configuration.

What am I doing wrong?

Answer 1

Looks like you are not going to rely on the Spring Boot's Kafka Auto Configuration.

Spring Boot provides in the KafkaAutoConfiguration:

@Bean
@ConditionalOnMissingBean(ConsumerFactory.class)
public ConsumerFactory<?, ?> kafkaConsumerFactory() {

Since you have jsonConsumerFactory and fileConsumerFactory, they override that one provided by the auto-config.

But on the other hand, in the KafkaAnnotationDrivenConfiguration, non of your factories can be applied:

@Bean
@ConditionalOnMissingBean(name = "kafkaListenerContainerFactory")
public ConcurrentKafkaListenerContainerFactory<?, ?> kafkaListenerContainerFactory(
        ConcurrentKafkaListenerContainerFactoryConfigurer configurer,
        ConsumerFactory<Object, Object> kafkaConsumerFactory) {

Because your ConsumerFactory beans are not of ConsumerFactory<Object, Object> type.

So:

• Just exclude KafkaAutoConfiguration from the Spring Boot auto configuration by adding the following to the application properties file: spring.autoconfigure.exclude=org.springframework.boot.autoconfigure.kafka.KafkaAutoConfiguration
• or rename one of your KafkaListenerContainerFactory beans to the kafkaListenerContainerFactory to override it in the Boot
• or make one of the ConsumerFactory beans as a ConsumerFactory<Object, Object> type.