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javaspring-bootspring-kafka

Programmatically setting properties when using @KafkaListener

I'm using the @KafkaListener annotation in my spring boot app without creating a custom KafkaListenerContainerFactory bean. I'm currently setting the spring.kafka.consumer.value-deserializer property in my application.yml file to assign my deserializer and prefer to do this programmatically to have compile time checks. I realize creating my own KafkaListenerContainerFactory allows me to set this property on the factory, but I'd like to avoid the boiler plate and some extra complications around getting the SSL setup.

Is there a simple way to set my value deserializer programmatically without creating my own KafkaListenerContainerFactory?

Solution

  • The deserializer goes on properties used to create the consumer factory, not the container factory, you can override boot's consumer factory as follows:

    @Bean
public ConsumerFactory<?, ?> kafkaConsumerFactory(KafkaProperties properties) {
    Map<String, Object> props = properties.buildConsumerProperties();
    props.put(ConsumerConfig.VALUE_DESERIALIZER_CLASS_CONFIG, MyDeserializer.class);
    return new DefaultKafkaConsumerFactory<>(props);
}