java - Spring-Cloud-Stream-Kafka-Binder 功能风格忽略自定义 De/Serializer 和/或 useNativeEncoding？

Question

我们刚刚升级到 Spring-Cloud-Stream 3.0.0 版本，遇到以下问题:

当使用这样的函数式风格时:

public class EventProcessor {

    private final PriceValidator priceValidator;

    @Bean
    public Function<Flux<EnrichedValidationRequest>, Flux<ValidationResult>> validate() {
        return enrichedValidationRequestFlux -> enrichedValidationRequestFlux
                .map(ProcessingContext::new)
                .flatMap(priceValidator::validateAndMap);
    }
}

application.yaml 如下所示:

spring.cloud.stream:
  default-binder: kafka
  kafka:
    binder:
      brokers: ${kafka.broker.prod}
      auto-create-topics: false
  function.definition: validate

# INPUT: enrichedValidationRequests
spring.cloud.stream.bindings.validate-in-0:
  destination: ${kafka.topic.${spring.application.name}.input.enrichedValidationRequests}
  group: ${spring.application.name}.${STAGE:NOT_SET}
  consumer:
    useNativeDecoding: true


spring.cloud.stream.kafka.bindings.validate-in-0:
  consumer:
    configuration:
      key.deserializer: org.apache.kafka.common.serialization.StringDeserializer
      value.deserializer: de.pricevalidator.deserializer.EnrichedValidationRequestDeserializer


# OUTPUT: validationResults
spring.cloud.stream.bindings.validate-out-0:
  destination: validationResultsTmp
  producer:
    useNativeEncoding: true

spring.cloud.stream.kafka.bindings.validate-out-0:
  producer:
    compression.type: lz4
    messageKeyExpression: payload.offerKey
    configuration:
      key.serializer: org.apache.kafka.common.serialization.StringSerializer
      value.serializer: de.pricevalidator.serializer.ValidationResultSerializer

序列化似乎完成了两次 - 当我们拦截 kafka 主题中生成的消息时，消费者只会将它们显示为 JSON(字符串)，但现在它是一个不可读的 byte[]。此外，生产中的下游消费者无法再反序列化消息。奇怪的是，输入消息的反序列化似乎工作得很好，无论我们在消费者属性中放入什么(无论是在 Binder 还是在默认的 kafka 级别) 我们有一种感觉，这个错误“又回来了”，但我们在代码中找不到确切的位置:https://github.com/spring-cloud/spring-cloud-stream/issues/1536

我们的(丑陋的)解决方法:

@Slf4j
@Configuration
public class KafkaMessageConverterConfiguration {

    @ConditionalOnProperty(value = "spring.cloud.stream.default-binder", havingValue = "kafka")
    @Bean
    public MessageConverter validationResultConverter(BinderTypeRegistry binder, ObjectMapper objectMapper) {
        return new AbstractMessageConverter(MimeType.valueOf("application/json")) {
            @Override
            protected boolean supports(final Class<?> clazz) {
                return ValidationResult.class.isAssignableFrom(clazz);
            }

            @Override
            protected Object convertToInternal(final Object payload, final MessageHeaders headers, final Object conversionHint) {
                return payload;
            }
        };
    }
}

是否有一种“正确”的方法来设置自定义序列化器或获取以前的 native 编码？

Answer 1

所以这是 3.0.0.RELEASE 之后报告的问题 - https://github.com/spring-cloud/spring-cloud-stream/commit/74aee8102898dbff96a570d2d2624571b259e141 。该问题已得到解决，几天后将在 3.0.1.RELEASE (Horsham.SR1) 中提供。