Regarding KafkaTemplate type parameters-CodePudding

I am using KafkaTemplate#send(Message<?>). I am not sending a key. I was wondering if it's ok to use type parameters of KafkaTemplate<Object,Object>? Would KafkaTemplate<Object, PlanDTO> be a more relevant type parameter? Are there any rules associated with this? I'm using spring boot 2.5.4 and jdk 11. Here's what I have:

@Component
public class PlanProducer 
{
    @Autowired
    private KafkaTemplate<Object, Object> kafkaTemplate;

    public void postPlanToKafka(PlanDTO plan)
    {
            Message<PlanDTO> message = MessageBuilder.withPayload(plan)
            .setHeader(KafkaHeaders.TOPIC, "plan")
            .setHeader(KafkaHeaders.TIMESTAMP, Instant.now().getEpochSecond())
            .build();
            ListenableFuture<SendResult<Object, Object>> future = kafkaTemplate.send(message);
            future.addCallback(new KafkaSendCallback<Object, Object>() 
            {
                @Override
                public void onSuccess(SendResult<Object, Object> result) 
                {
                    RecordMetadata metadata = result.getRecordMetadata();
                    log.info("Message sent successfully with the following information : topic - {} , "
                              "partition  - {} , offset - {}",metadata.topic(),
                            metadata.partition(),metadata.offset());
                }

                @Override
                public void onFailure(KafkaProducerException e) 
                {
                    log.error("Error posting data to kafka ={}",e);
                }
            });
    }
}

CodePudding user response：

It is perfectly fine to use <Object, Object>.

There are no "rules" since the actual types are determined by the serializers.

The new receive() methods in 2.8 will need a narrrower type, but for sending, it is not an issue.