Bootstrap

SpringCloudStreamkafka接收jsonarray字符串失败

场景现象

  • kafka作为消息队列,作为前端设备数据到后端消费的渠道,也被多个不同微服务消费
  • 一个服务与前端边缘计算设备建立socket消息,接收实时交通事件推送,再将事件发送到kafka里面。此处使用的是Spring Kafka,普通的将事件列表数据转化为字符串后发送
  • 事件信息,需要入库和实时推送,也需要被第三方服务调用,第三方也采取消费kafka的方式
  • 这个服务,作为kafka的消费者,读取事件数据,发送短信给指定用户,但此处使用的是Spring.cloud.stream,函数式编程,绑定kafka的topic
  • 此服务消费时,加了一些打印。但是事件推送到kafka后,看不到任何日志打印,也没有报错。但是使用kafka命令查看,却已经被该消费者消费掉了
  • 消费方,配置文件如下:
spring:
  cloud:
    stream:
      function:
        definition: vipRouteGpsConsumer;offlineEventConsumer;boxEventTopicConsumer
      bindings:
        vipRouteGpsConsumer-in-0:
          destination: vipRouteGps
        offlineEventConsumer-in-0:
          destination: offlineEvent
        boxEventTopicConsumer-in-0:
          destination: boxTopic
  • 消费的源代码如下:
@Configuration
public class KafkaConfiguration {
    @Bean
    public Consumer<String> boxEventTopicConsumer() {
        return value -> {
            log.info("Consumer Received (boxTopic): " + value);
            // todo : do somethings
        };
    }
}

Spring Cloud Stream介绍

  • Spring Cloud Stream是一个用于构建消息驱动的微服务应用程序的框架
  • 它基于Spring Boot和Spring Integration,提供了一种简单而灵活的方式来连接消息代理和应用程序
  • Spring Cloud Stream的核心概念包括:
    • Binder:Binder是Spring Cloud Stream的核心组件,它提供了与消息代理交互的适配器。Spring Cloud Stream提供了对多种消息代理的支持,如Kafka、RabbitMQ等。
    • Destination:Destination代表了消息的目的地,它可以是一个主题(Topic)或者一个队列(Queue)。
    • Message:Message是Spring Cloud Stream中的基本单位,它包含了消息的负载和一些元数据。
    • Producer:Producer用于向消息代理发送消息。
    • Consumer:Consumer用于从消息代理接收消息
  • Spring Cloud Stream提供了两种方式来定义消息驱动的应用程序:
    • 使用注解:通过在方法上添加注解来定义消息的生产者和消费者。
    • 使用函数式编程模型:通过定义输入和输出的Binding来创建消息的生产者和消费者
  • Spring Cloud Stream还提供了一些附加功能,如消息转换、消息分组、消息持久化等,以满足不同场景下的需求。通过使用Spring Cloud Stream,开发人员可以更加轻松地构建和管理消息驱动的微服务应用程序

问题处理

  • 消费某个多分区topic时,发现只有其中一个分区数据有打印,其他都没有,但是查看却发现都消费掉了
2023-09-21 13:45:13.706  INFO 2184 --- [container-0-C-1] c.newatc.data.kafka.KafkaConfiguration   : Consumer Received (boxTopic): {"equipmentNo":0,"laneNum":4,"statisticsCycle":60,"time":1695275100110,"vehicleLanes":[{"averageParkingNum":0.5,"averageSpeed":6.1,"lane":1,"laneFlow":2,"maxQueueLength":12,"nonVehicleAverageTravelTime":0.0,"overStopLineFlow":2,"pedestrianAverageTravelTime":0,"vehicleAverageDelay":15.3,"vehicleAverageTravelTime":0.2},{"averageParkingNum":0.0,"averageSpeed":35.7,"lane":2,"laneFlow":1,"maxQueueLength":0,"nonVehicleAverageTravelTime":0.0,"overStopLineFlow":1,"pedestrianAverageTravelTime":0,"vehicleAverageDelay":0.0,"vehicleAverageTravelTime":0.0},{"averageParkingNum":0.0,"averageSpeed":0.0,"lane":3,"laneFlow":3,"maxQueueLength":0,"nonVehicleAverageTravelTime":0.0,"overStopLineFlow":0,"pedestrianAverageTravelTime":0,"vehicleAverageDelay":0.0,"vehicleAverageTravelTime":0.0},{"averageParkingNum":0.0,"averageSpeed":25.4,"lane":4,"laneFlow":1,"maxQueueLength":0,"nonVehicleAverageTravelTime":0.0,"overStopLineFlow":5,"pedestrianAverageTravelTime":0,"vehicleAverageDelay":0.0,"vehicleAverageTravelTime":1.6}]}
  • 最终测试发现,列表转化为jsonarray字符串,无法打印。但是单条数据json字符串却可以
  • 将代码改为String[]后发现报错,代码如下
    @Bean
    public Consumer<String[]> boxEventTopicConsumer(HWTrafficEventManager hwTrafficEventManager) {
        log.info("Consumer Received (boxTopic): " + hwTrafficEventManager);
        return value -> {
            log.info("Consumer Received (boxTopic): " + value.length);

        };
    }
  • 报错如下:
2023-09-21 11:47:59.684 ERROR 9112 --- [container-0-C-1] o.s.kafka.listener.DefaultErrorHandler   : Backoff none exhausted for boxTopic-3@29941

org.springframework.kafka.listener.ListenerExecutionFailedException: Listener failed; nested exception is org.springframework.messaging.converter.MessageConversionException: Could not read JSON: Cannot deserialize value of type `[Ljava.lang.String;` from Object value (token `JsonToken.START_OBJECT`)
 at [Source: (byte[])"[{"equipmentNo":0,"eventCode":8,"eventType":1,"laneTurn":0,"relationNo":1,"time":1695267981221}]"; line: 1, column: 2] (through reference chain: java.lang.Object[][0]); nested exception is com.fasterxml.jackson.databind.exc.MismatchedInputException: Cannot deserialize value of type `[Ljava.lang.String;` from Object value (token `JsonToken.START_OBJECT`)
 at [Source: (byte[])"[{"equipmentNo":0,"eventCode":8,"eventType":1,"laneTurn":0,"relationNo":1,"time":1695267981221}]"; line: 1, column: 2] (through reference chain: java.lang.Object[][0]), failedMessage=GenericMessage [payload=byte[96], headers={kafka_offset=29941, kafka_consumer=org.apache.kafka.clients.consumer.KafkaConsumer@3c31888e, deliveryAttempt=3, kafka_timestampType=CREATE_TIME, kafka_receivedPartitionId=3, kafka_receivedMessageKey=[B@3fcf7bd1, kafka_receivedTopic=boxTopic, kafka_receivedTimestamp=1695267871945, contentType=application/json, kafka_groupId=data-center}]
	at org.springframework.kafka.listener.KafkaMessageListenerContainer$ListenerConsumer.decorateException(KafkaMessageListenerContainer.java:2683)
	at org.springframework.kafka.listener.KafkaMessageListenerContainer$ListenerConsumer.doInvokeOnMessage(KafkaMessageListenerContainer.java:2649)
	at org.springframework.kafka.listener.KafkaMessageListenerContainer$ListenerConsumer.invokeOnMessage(KafkaMessageListenerContainer.java:2609)
	at org.springframework.kafka.listener.KafkaMessageListenerContainer$ListenerConsumer.doInvokeRecordListener(KafkaMessageListenerContainer.java:2536)
	at org.springframework.kafka.listener.KafkaMessageListenerContainer$ListenerConsumer.doInvokeWithRecords(KafkaMessageListenerContainer.java:2427)
	at org.springframework.kafka.listener.KafkaMessageListenerContainer$ListenerConsumer.invokeRecordListener(KafkaMessageListenerContainer.java:2305)
	at org.springframework.kafka.listener.KafkaMessageListenerContainer$ListenerConsumer.invokeListener(KafkaMessageListenerContainer.java:1979)
	at org.springframework.kafka.listener.KafkaMessageListenerContainer$ListenerConsumer.invokeIfHaveRecords(KafkaMessageListenerContainer.java:1364)
	at org.springframework.kafka.listener.KafkaMessageListenerContainer$ListenerConsumer.pollAndInvoke(KafkaMessageListenerContainer.java:1355)
	at org.springframework.kafka.listener.KafkaMessageListenerContainer$ListenerConsumer.run(KafkaMessageListenerContainer.java:1247)
	at java.base/java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:515)
	at java.base/java.util.concurrent.FutureTask.run$$$capture(FutureTask.java:264)
	at java.base/java.util.concurrent.FutureTask.run(FutureTask.java)
	at java.base/java.lang.Thread.run(Thread.java:834)
Caused by: org.springframework.messaging.converter.MessageConversionException: Could not read JSON: Cannot deserialize value of type `[Ljava.lang.String;` from Object value (token `JsonToken.START_OBJECT`)
 at [Source: (byte[])"[{"equipmentNo":0,"eventCode":8,"eventType":1,"laneTurn":0,"relationNo":1,"time":1695267981221}]"; line: 1, column: 2] (through reference chain: java.lang.Object[][0]); nested exception is com.fasterxml.jackson.databind.exc.MismatchedInputException: Cannot deserialize value of type `[Ljava.lang.String;` from Object value (token `JsonToken.START_OBJECT`)
 at [Source: (byte[])"[{"equipmentNo":0,"eventCode":8,"eventType":1,"laneTurn":0,"relationNo":1,"time":1695267981221}]"; line: 1, column: 2] (through reference chain: java.lang.Object[][0])
	at org.springframework.messaging.converter.MappingJackson2MessageConverter.convertFromInternal(MappingJackson2MessageConverter.java:237)
	at org.springframework.cloud.stream.converter.ApplicationJsonMessageMarshallingConverter.convertFromInternal(ApplicationJsonMessageMarshallingConverter.java:113)
	at org.springframework.messaging.converter.AbstractMessageConverter.fromMessage(AbstractMessageConverter.java:185)
	at org.springframework.messaging.converter.AbstractMessageConverter.fromMessage(AbstractMessageConverter.java:176)
	at org.springframework.cloud.function.context.config.SmartCompositeMessageConverter.fromMessage(SmartCompositeMessageConverter.java:48)
	at org.springframework.cloud.function.context.catalog.SimpleFunctionRegistry$FunctionInvocationWrapper.convertInputMessageIfNecessary(SimpleFunctionRegistry.java:1282)
	at org.springframework.cloud.function.context.catalog.SimpleFunctionRegistry$FunctionInvocationWrapper.convertInputIfNecessary(SimpleFunctionRegistry.java:1057)
	at org.springframework.cloud.function.context.catalog.SimpleFunctionRegistry$FunctionInvocationWrapper.doApply(SimpleFunctionRegistry.java:696)
	at org.springframework.cloud.function.context.catalog.SimpleFunctionRegistry$FunctionInvocationWrapper.apply(SimpleFunctionRegistry.java:551)
	at org.springframework.cloud.stream.function.PartitionAwareFunctionWrapper.apply(PartitionAwareFunctionWrapper.java:84)
	at org.springframework.cloud.stream.function.FunctionConfiguration$FunctionWrapper.apply(FunctionConfiguration.java:754)
	at org.springframework.cloud.stream.function.FunctionConfiguration$FunctionToDestinationBinder$1.handleMessageInternal(FunctionConfiguration.java:586)
	at org.springframework.integration.handler.AbstractMessageHandler.handleMessage(AbstractMessageHandler.java:56)
	at org.springframework.integration.dispatcher.AbstractDispatcher.tryOptimizedDispatch(AbstractDispatcher.java:115)
	at org.springframework.integration.dispatcher.UnicastingDispatcher.doDispatch(UnicastingDispatcher.java:133)
	at org.springframework.integration.dispatcher.UnicastingDispatcher.dispatch(UnicastingDispatcher.java:106)
	at org.springframework.integration.channel.AbstractSubscribableChannel.doSend(AbstractSubscribableChannel.java:72)
	at org.springframework.integration.channel.AbstractMessageChannel.send(AbstractMessageChannel.java:317)
	at org.springframework.integration.channel.AbstractMessageChannel.send(AbstractMessageChannel.java:272)
	at org.springframework.messaging.core.GenericMessagingTemplate.doSend(GenericMessagingTemplate.java:187)
	at org.springframework.messaging.core.GenericMessagingTemplate.doSend(GenericMessagingTemplate.java:166)
	at org.springframework.messaging.core.GenericMessagingTemplate.doSend(GenericMessagingTemplate.java:47)
	at org.springframework.messaging.core.AbstractMessageSendingTemplate.send(AbstractMessageSendingTemplate.java:109)
	at org.springframework.integration.endpoint.MessageProducerSupport.sendMessage(MessageProducerSupport.java:216)
	at org.springframework.integration.kafka.inbound.KafkaMessageDrivenChannelAdapter.sendMessageIfAny(KafkaMessageDrivenChannelAdapter.java:397)
	at org.springframework.integration.kafka.inbound.KafkaMessageDrivenChannelAdapter.access$300(KafkaMessageDrivenChannelAdapter.java:83)
	at org.springframework.integration.kafka.inbound.KafkaMessageDrivenChannelAdapter$IntegrationRecordMessageListener.onMessage(KafkaMessageDrivenChannelAdapter.java:454)
	at org.springframework.integration.kafka.inbound.KafkaMessageDrivenChannelAdapter$IntegrationRecordMessageListener.onMessage(KafkaMessageDrivenChannelAdapter.java:428)
	at org.springframework.kafka.listener.adapter.RetryingMessageListenerAdapter.lambda$onMessage$0(RetryingMessageListenerAdapter.java:125)
	at org.springframework.retry.support.RetryTemplate.doExecute(RetryTemplate.java:329)
	at org.springframework.retry.support.RetryTemplate.execute(RetryTemplate.java:255)
	at org.springframework.kafka.listener.adapter.RetryingMessageListenerAdapter.onMessage(RetryingMessageListenerAdapter.java:119)
	at org.springframework.kafka.listener.adapter.RetryingMessageListenerAdapter.onMessage(RetryingMessageListenerAdapter.java:42)
	at org.springframework.kafka.listener.KafkaMessageListenerContainer$ListenerConsumer.doInvokeOnMessage(KafkaMessageListenerContainer.java:2629)
	... 12 common frames omitted
Caused by: com.fasterxml.jackson.databind.exc.MismatchedInputException: Cannot deserialize value of type `[Ljava.lang.String;` from Object value (token `JsonToken.START_OBJECT`)
 at [Source: (byte[])"[{"equipmentNo":0,"eventCode":8,"eventType":1,"laneTurn":0,"relationNo":1,"time":1695267981221}]"; line: 1, column: 2] (through reference chain: java.lang.Object[][0])
	at com.fasterxml.jackson.databind.exc.MismatchedInputException.from(MismatchedInputException.java:59)
	at com.fasterxml.jackson.databind.DeserializationContext.reportInputMismatch(DeserializationContext.java:1741)
	at com.fasterxml.jackson.databind.DeserializationContext.handleUnexpectedToken(DeserializationContext.java:1515)
	at com.fasterxml.jackson.databind.DeserializationContext.handleUnexpectedToken(DeserializationContext.java:1420)
	at com.fasterxml.jackson.databind.DeserializationContext.extractScalarFromObject(DeserializationContext.java:932)
	at com.fasterxml.jackson.databind.deser.std.StdDeserializer._parseString(StdDeserializer.java:1292)
	at com.fasterxml.jackson.databind.deser.std.StringArrayDeserializer.deserialize(StringArrayDeserializer.java:166)
	at com.fasterxml.jackson.databind.deser.std.StringArrayDeserializer.deserialize(StringArrayDeserializer.java:25)
	at com.fasterxml.jackson.databind.deser.DefaultDeserializationContext.readRootValue(DefaultDeserializationContext.java:322)
	at com.fasterxml.jackson.databind.ObjectMapper._readMapAndClose(ObjectMapper.java:4674)
	at com.fasterxml.jackson.databind.ObjectMapper.readValue(ObjectMapper.java:3723)
	at org.springframework.messaging.converter.MappingJackson2MessageConverter.convertFromInternal(MappingJackson2MessageConverter.java:223)
	... 45 common frames omitted
  • 通过日志可以看出,是在接收数据的解析时发生了问题,jsonarray的字符串无法接受解析
  • 在消息发生时,在正常消息后面,加一个“-”,可以正常接收了,就是解析时需要先删掉尾字符再转json
  • 后面又发现,如果是作为字符数组接收,再转为字符串,是可以的
  • 相应配置
spring:
  cloud:
    stream:
      function:
        definition: boxEventTopicConsumer
      bindings:
        boxEventTopicConsumer-in-0:
          destination: boxTopic
          group: data-center
          contentType: application/json
  • 消费者消费代码
@Configuration
public class KafkaConfiguration {
    @Bean
    public Consumer<Object> boxEventTopicConsumer() {
        return value -> {
            String str = new String((byte[])value, java.nio.charset.StandardCharsets.UTF_8);
            log.info("Consumer Received (boxTopic): " + str);
            // todo : do somethings
        };
    }
;