java - Spring Kafka 自定义反序列化器

Question

我正在按照此link中列出的步骤进行操作创建客户解串器。我从 Kafka 收到的消息在 json 字符串之前有纯文本“log message -”。我希望反序列化器忽略该字符串并解析 json 数据。有办法做到吗？

申请

@SpringBootApplication
public class TransactionauditServiceApplication {

    public static void main(String[] args) throws InterruptedException {
        new SpringApplicationBuilder(TransactionauditServiceApplication.class).web(false).run(args);
    }

    @Bean
    public MessageListener messageListener() {
        return new MessageListener();
    }

    public static class MessageListener {

        @KafkaListener(topics = "ctp_verbose", containerFactory = "kafkaListenerContainerFactory")
        public void listen(@Payload ConciseMessage message, 
                  @Header(KafkaHeaders.RECEIVED_PARTITION_ID) int partition) {
            System.out.println("Received Messasge in group foo: " + message.getStringValue("traceId") + " partion " + partition);
        }
    }
}

消费者配置

@EnableKafka
@Configuration
public class KafkaConsumerConfig {

    @Value(value = "${kafka.bootstrapAddress:localhost:9092}")
    private String bootstrapAddress;

    @Value(value = "${groupId:audit}")
    private String groupId;

    @Bean
    public ConsumerFactory<String, ConciseMessage> consumerFactory() {
        Map<String, Object> props = new HashMap<>();
        props.put(ConsumerConfig.BOOTSTRAP_SERVERS_CONFIG, bootstrapAddress);
        props.put(ConsumerConfig.GROUP_ID_CONFIG, groupId);
        return new DefaultKafkaConsumerFactory<>(props, new StringDeserializer(), new JsonDeserializer<>(ConciseMessage.class));
    }

    @Bean
    public ConcurrentKafkaListenerContainerFactory<String, ConciseMessage> kafkaListenerContainerFactory() {

        ConcurrentKafkaListenerContainerFactory<String, ConciseMessage> factory = new ConcurrentKafkaListenerContainerFactory<>();
        factory.setConsumerFactory(consumerFactory());
        return factory;
    }
}

Answer 1

通过编写行 new JsonDeserializer<>(ConciseMessage.class) ，您只是告诉 Kafka 您要将消息转换为 ConciseMessage类型。因此，这并不意味着它是一个自定义解串器。要解决您的问题，您很可能必须想出自己的反序列化器实现，该实现具有剥离文本“日志消息 -”的逻辑。