使用Avro

时间:2018-11-08 14:15:53

标签: java apache-kafka apache-kafka-streams spring-kafka confluent-schema-registry

我们有一个kTable,其中我们使用以下代码映射值并实现到KeyValueStore:

    @Bean
    public KTable<String, CancelEvent> kTable(StreamsBuilder kStreamBuilder,
                                          ValueMapper<CancelEvent, CancelEvent> mapper,
                                          SpecificAvroSerde<CancelEvent> serde) {

      return kStreamBuilder
            .table(properties.getProperty("topics.cancel"), Consumed.with(Serdes.String(), serde))
            .mapValues(mapper, Materialized.as("cancel-event-store"));

    }

以及映射器代码:

    @Override
    public CancelEvent apply(CancelEvent value) {

      if (value.getData().getCancelled()) {
        return null;
      }

      return value;

    }

我们使用Avro进行序列化和反序列化。当我们尝试使用键查询state store时,它总是返回null

用于查询状态存储的代码:

    ReadOnlyKeyValueStore<String, CancelEvent> store = streamsFactory.getKafkaStreams()
            .store("cancel-event-store", QueryableStoreTypes.keyValueStore());

    CancelEvent event = store.get(queryEvent.getMeta().getId().toString());

event始终为null。在调试时,我遍历了keyValuestore,并意识到密钥上有某些内容(魔术字节可能是!)。请参考下图

enter image description here

所以,问题是如何用键查询?

更新1

    private Map<String, Object> kStreamsConfigsProperties() {
    final Map<String, Object> config = new HashMap<>();

    config.put(APPLICATION_ID_CONFIG, "app.name" + new Date().getTime());

    config.put(BOOTSTRAP_SERVERS_CONFIG, properties.getProperty("spring.kafka.bootstrap-servers"));
    config.put(AbstractKafkaAvroSerDeConfig.SCHEMA_REGISTRY_URL_CONFIG, properties.getProperty("spring.kafka.schema-registry"));

    config.put(DEFAULT_KEY_SERDE_CLASS_CONFIG, Serdes.String().getClass().getName());
    config.put(DEFAULT_VALUE_SERDE_CLASS_CONFIG, SpecificAvroSerde.class.getName());
    config.put(DEFAULT_TIMESTAMP_EXTRACTOR_CLASS_CONFIG, WallclockTimestampExtractor.class.getName());

    return config;
}

0 个答案:

没有答案