Question

Kafka原生API允许我们create and add a state store using the StreamsBuilder：

    final StreamsBuilder builder = new StreamsBuilder();
    ...
    final StoreBuilder<WindowStore<String, Long>> dedupStoreBuilder = Stores.windowStoreBuilder(
            Stores.persistentWindowStore(storeName,
                                         retentionPeriod,
                                         windowSize,
                                         false
            ),
            Serdes.String(),
            Serdes.Long());

    builder.addStateStore(dedupStoreBuilder);

我想使用Spring Cloud Streams进行相同的操作，但无法找出访问StreamsBuilder来添加商店的方式。

我尝试按照doc中的说明检索StreamsBuilderFactoryBean，希望它可以从中获取StreamsBuilder对象，但是bean似乎不可用：

@EnableBinding(KafkaStreamsProcessor::class)
class FraudKafkaStreamsConfiguration(private val context: ApplicationContext) {

    @StreamListener
    @SendTo("output")
    fun process(@Input("input") input: KStream<String, TransferEmitted>): KStream<String, TransferEmitted> {

        val streamsBuilderFactoryBean = context.getBean("&stream-builder-process", StreamsBuilderFactoryBean::class.java)
        ...
        return xxx

    }

}

原因： org.springframework.beans.factory.NoSuchBeanDefinitionException：否名为“ stream-builder-process”的bean可用

无论如何，我什至不确定这是否是正确的方法。那么，我们如何以编程方式创建StateStore？

Answer 1

由于我的Scs版本（Fishtown SR3），我没有看到记录的程序，但是好消息是，自Germantown以来，可以声明式创建State Store：

const val DEDUP_STORE = "dedup-store"

@EnableBinding(KafkaStreamsProcessor::class)
class FraudKafkaStreamsConfiguration {

    @KafkaStreamsStateStore(name = DEDUP_STORE, type = KafkaStreamsStateStoreProperties.StoreType.KEYVALUE)
    @StreamListener
    @SendTo("output")
    fun process(@Input("input") input: KStream<String, TransferEmitted>): KStream<String, TransferEmitted> {
        return input.transform(TransformerSupplier { DeduplicationTransformer() }, DEDUP_STORE)

    }

}

如何在Spring Cloud Stream Kafka Streams应用程序中使用StateStoreBuilder添加StateStore

1 个答案: