使用Spring Kafka反序列化來自同一Kafka主題的不同JSON有效負載

Question

我正在嘗試反序列化來自同一Kafka主題的不同JSON負載。 在這里提出的其他問題使我第一次嘗試，但是我無法使其運行。

正如Gary提到的（ 這里 ），有一些提示（ JsonSerializer.ADD_TYPE_INFO_HEADERS ），但是當我發送和接收這兩個消息時，我都會遇到異常。

org.springframework.kafka.listener.ListenerExecutionFailedException: Listener method could not be invoked with the incoming message
Endpoint handler details:
Method [public void com.foo.message.ConsumerImpl.consumeSelf(java.lang.String,java.lang.String,java.lang.String,java.lang.String,java.util.Map<java.lang.String, java.lang.Object>,com.foo.message.KafkaMessage,org.apache.kafka.clients.consumer.ConsumerRecord<java.lang.String, java.lang.Object>)]
Bean [com.foo.message.ConsumerImpl@6df2a206]; nested exception is org.springframework.messaging.converter.MessageConversionException: Cannot handle message; nested exception is org.springframework.messaging.converter.MessageConversionException: Cannot convert from [com.foo.message.KafkaMessageWithAdditionalField] to [com.foo.message.KafkaMessage] for GenericMessage [payload=com.foo.message.KafkaMessageWithAdditionalField@4e3168f7, headers={kafka_offset=22, kafka_consumer=org.apache.kafka.clients.consumer.KafkaConsumer@c0e2fcf, kafka_timestampType=CREATE_TIME, kafka_receivedMessageKey=null, kafka_receivedPartitionId=0, kafka_receivedTopic=fromBar, kafka_receivedTimestamp=1548310583481}], failedMessage=GenericMessage [payload=com.foo.message.KafkaMessageWithAdditionalField@4e3168f7, headers={kafka_offset=22, kafka_consumer=org.apache.kafka.clients.consumer.KafkaConsumer@c0e2fcf, kafka_timestampType=CREATE_TIME, kafka_receivedMessageKey=null, kafka_receivedPartitionId=0, kafka_receivedTopic=fromBar, kafka_receivedTimestamp=1548310583481}]
    at org.springframework.kafka.listener.adapter.MessagingMessageListenerAdapter.invokeHandler(MessagingMessageListenerAdapter.java:292) ~[spring-kafka-2.2.2.RELEASE.jar:2.2.2.RELEASE]
    at org.springframework.kafka.listener.adapter.RecordMessagingMessageListenerAdapter.onMessage(RecordMessagingMessageListenerAdapter.java:79) ~[spring-kafka-2.2.2.RELEASE.jar:2.2.2.RELEASE]
    at org.springframework.kafka.listener.adapter.RecordMessagingMessageListenerAdapter.onMessage(RecordMessagingMessageListenerAdapter.java:50) ~[spring-kafka-2.2.2.RELEASE.jar:2.2.2.RELEASE]
    at org.springframework.kafka.listener.KafkaMessageListenerContainer$ListenerConsumer.doInvokeOnMessage(KafkaMessageListenerContainer.java:1207) [spring-kafka-2.2.2.RELEASE.jar:2.2.2.RELEASE]

...

LoggingErrorHandler已經在ConsumerRecord中提到了一個（正確的）值。

2019-01-24 07:16:27.630 ERROR 27204 --- [ntainer#2-0-C-1] o.s.kafka.listener.LoggingErrorHandler   : Error while processing: ConsumerRecord(topic = fromBar, partition = 0, offset = 22, CreateTime = 1548310583481, serialized key size = -1, serialized value size = 196, headers = RecordHeaders(headers = [], isReadOnly = false), key = null, value = com.foo.bar.message.KafkaMessageWithAdditionalField@4e3168f7)

首先我的配置：

@EnableKafka
@Configuration
public class KafkaConsumerConfig {
    @Value("${spring.kafka.bootstrap-servers}")
    private String bootstrapServers;

    @Bean
    public ConsumerFactory<String, KafkaMessage> consumerFactoryMessage()
    {
        Map<String, Object> props = new HashMap<>();
        props.put(ConsumerConfig.BOOTSTRAP_SERVERS_CONFIG, bootstrapServers);           
        props.put(ConsumerConfig.KEY_DESERIALIZER_CLASS_CONFIG, StringDeserializer.class);
        props.put(ConsumerConfig.VALUE_DESERIALIZER_CLASS_CONFIG, JsonDeserializer.class);
        return new DefaultKafkaConsumerFactory<>(props, new StringDeserializer(),
                new JsonDeserializer<>(KafkaMessage.class));
    }

    @Bean
    public ConcurrentKafkaListenerContainerFactory<String, KafkaMessage> kafkaListenerMessageContainerFactory()
    {
        ConcurrentKafkaListenerContainerFactory<String, KafkaMessage> factory = new ConcurrentKafkaListenerContainerFactory<>();
        factory.setConsumerFactory(consumerFactoryMessage());
        return factory;
    }

    @Bean
    public ConsumerFactory<String, KafkaMessageWithAdditionalField> consumerFactoryMessageWithAdditionalField()
    {
        Map<String, Object> props = new HashMap<>();
        props.put(ConsumerConfig.BOOTSTRAP_SERVERS_CONFIG, bootstrapServers);
        props.put(ConsumerConfig.KEY_DESERIALIZER_CLASS_CONFIG, StringDeserializer.class);
        props.put(ConsumerConfig.VALUE_DESERIALIZER_CLASS_CONFIG, JsonDeserializer.class);
        return new DefaultKafkaConsumerFactory<>(props, new StringDeserializer(),
                new JsonDeserializer<>(KafkaMessageWithAdditionalField.class));
    }

    @Bean
    public ConcurrentKafkaListenerContainerFactory<String, KafkaMessageWithAdditionalField> kafkaListenerMessageWithAdditionalFieldContainerFactory()
    {
        ConcurrentKafkaListenerContainerFactory<String, KafkaMessageWithAdditionalField> factory = new ConcurrentKafkaListenerContainerFactory<>();
        factory.setConsumerFactory(consumerFactoryMessageWithAdditionalField());
        return factory;
    }
}

這是聽眾：

    @KafkaListener(topicPartitions = @TopicPartition(partitions = "0", topic = "${foo.kafka.topic-springBoot}"), containerFactory = "kafkaListenerMessageContainerFactory")
    public void consumeSelf(@Headers Map<String, Object> map, KafkaMessage message, ConsumerRecord<String, Object> cr)
    {
        log.info("message received %s", message);
    }

    @KafkaListener(topicPartitions = @TopicPartition(partitions = "0", topic = "${foo.kafka.topic-springBoot}"), containerFactory = "kafkaListenerMessageWithAdditionalFieldContainerFactory")
    public void consumeSelfAdd(@Headers Map<String, Object> map, KafkaMessageWithAdditionalField message, ConsumerRecord<String, Object> cr)
    {
        log.info("messageKafkaMessageWithAdditionalField received %s", message);
    }

Answer 1

你不能那樣做； 您有2個不同的偵聽器容器，其中的偵聽器期望使用不同的對象。

對於接收不同類型的多個監聽器方法，你需要使用@KafkaListener類級別和@KafkaHandler在方法級別。

請參見有關類的@KafkaListener 。

在類級別使用@KafkaListener時，請在方法級別指定@KafkaHandler。 傳遞消息時，將使用轉換后的消息有效負載類型來確定要調用的方法。

@KafkaListener(id = "multi", topics = "myTopic")
static class MultiListenerBean {

    @KafkaHandler
    public void listen(String foo) {
        ...
    }

    @KafkaHandler
    public void listen(Integer bar) {
        ...
    }

    @KafkaHandler(isDefault = true`)
    public void listenDefault(Object object) {
        ...
    }

}

默認方法是可選的，用於未知的有效負載類型。

但這僅適用於智能解串器（知道如何轉換為不同的有效負載）。

或者，您可以將RecordFilterStrategy添加到偵聽器容器工廠，以跳過每個偵聽器中的其他記錄。