Get underlying low-level Kafka consumers and Producers in Spring Cloud Stream

Question

I have a usecase where I want to get the underlying Kafka producer (KafkaTemplate) in a Spring Cloud Stream application. While navigating the code I stumbled upon KafkaProducerMessageHandler which has a getKafkaTemplate method. However, it fails to auto-wire.

Also, if I directly auto-wire KafkaTemplate, the template is initialized with default properties and it ignores the broker in the binder key of the SCSt configuration

How can I access the underlying KafkaTemplate or a producer/consumer in a Spring Cloud Stream app?

EDIT: Actually my SCSt app has multiple Kafka binders and I want to get the KafkaTemplate or Kafka producer corresponding to each binder. Is that possible somehow?

score 0 · Answer 1 · answered Jul 07 '20 at 14:13

0

It's not entirely clear why you would need to do that, but you can capture the KafkaTemplates by adding a ProducerMessageHandlerCustomizer @Bean to the application context.

answered Jul 07 '20 at 14:13

Gary Russell

166,535
14
146
179

Hi Gary. Thank you for your response. Unfortunately, `ProducerMessageHandlerCustomizer` was not added until SCSt 3.0. I am still using SCSt 2.2 and I cannot update. Is there any other way to capture the `KafkaTemplate`s? – cannot_mutably_borrow Jul 07 '20 at 14:39
No; sorry; there is not. Perhaps if you can explain your use case, there might be some alternative. – Gary Russell Jul 07 '20 at 15:20
Is there a sample usage of `ProducerMessageHandlerCustomizer` documented anywhere, Gary? – cannot_mutably_borrow Jul 09 '20 at 03:13

Get underlying low-level Kafka consumers and Producers in Spring Cloud Stream

1 Answers1