Question

我正在尝试根据应用程序中消息处理的状态来控制对kafka主题的偏移提交。如果消息成功，则可以提交偏移量。为此，我尝试在方法中获取标头，以便可以手动确认消息

  spring:
   cloud:
    stream:
      default:
        contentType: application/json
      default-binder: binder1-kafka
      bindings:
        myChannel:
          binder: binder1-kafka
          destination: my_topic
          content-type: text/plain
          consumer:
            autoCommitOffset: false

        outChannel:
          binder: binder2-kafka
          destination: my_topic
          content-type: text/plain
          consumer:
            autoCommitOffset: false    


      binders:
        #Connection config to different clusters
        binder1-kafka:
          type: kafka
          defaultCandidate: true
          environment:
            spring:
              cloud:
                stream:
                  kafka:
                    binder:
                      brokers: some-url1:9092
        binder2-kafka:
          type: kafka
          defaultCandidate: false
          environment:
            spring:
              cloud:
                stream:
                  kafka:
                    binder:
                      brokers: some-url2:9092

但是在将侦听器用作

时

@StreamListener(target = IBrokerChannel.myChannel )
public void handlePayload(@Payload MyPayload payload, @Headers Map<String, Object> headers) {
  Acknowledgment acknowledgment= (Acknowledgment) headers.get("kafka_acknowledgment"); // acknowledgment object is always null.
  acknowledgment.acknowledge();
}

acknowledgment始终为null。我正在使用kafka生产者cli将消息发送到主题。 spring-boot的版本为1.5.10.RELEASE

Answer 1

您在配置属性定义中缺少kafka分支。一定是这样的：

spring:
   cloud:
    stream:
      default-binder: kafka
      kafka:
         bindings:
           myChannel:
             consumer:
               autoCommitOffset: false

https://docs.spring.io/spring-cloud-stream/docs/Fishtown.BUILD-SNAPSHOT/reference/htmlsingle/#kafka-consumer-properties

Answer 2

对我来说很好...

@SpringBootApplication
@EnableBinding(Sink.class)
public class So51159949Application {

    public static void main(String[] args) {
        SpringApplication.run(So51159949Application.class, args);
    }

    @Bean
    public ApplicationRunner runner(KafkaTemplate<byte[], byte[]> template) {
        return args -> {
            template.send("so51159949", "foo".getBytes());
        };
    }

    @StreamListener(Sink.INPUT)
    public void in(String in, @Headers MessageHeaders headers) {
        System.out.println(in);
        System.out.println(headers);
        Acknowledgment ack = headers.get(KafkaHeaders.ACKNOWLEDGMENT, Acknowledgment.class);
        ack.acknowledge();
    }

}

和

spring:
  cloud:
    stream:
      bindings:
        input:
          group: so51159949
          destination: so51159949
      kafka:
        bindings:
          input:
            consumer:
              auto-commit-offset: false

和

foo
{kafka_offset=2, kafka_consumer=org.apache.kafka.clients.consumer.KafkaConsumer@4ad39b5f, deliveryAttempt=1, kafka_timestampType=CREATE_TIME, kafka_receivedMessageKey=null, kafka_receivedPartitionId=0, kafka_receivedTopic=so51159949, kafka_receivedTimestamp=1530643662028, kafka_acknowledgment=Acknowledgment for ConsumerRecord(topic = so51159949, partition = 0, offset = 2, CreateTime = 1530643662028, serialized key size = -1, serialized value size = 3, headers = RecordHeaders(headers = [], isReadOnly = false), key = null, value = [B@700c9aa9), contentType=application/json}

春季云流：标头kafka_acknowledgment值为null

2 个答案: