Question

我正在尝试使用spring-cloud-stream-binder-kafka-streams项目阅读KTable。我们可以使用spring @StreamListener和spring-cloud-streams提供的所有接口来读取KTable。

我在阅读KTable时遇到LongDeserializer异常。

我正在使用springCloudVersion = 'Finchley.RC1' springBootVersion = '2.0.1.RELEASE'

该项目的github link位于， https://github.com/jaysara/KStreamAnalytics

这是堆栈跟踪，

Exception in thread "panalytics-ac0fa75f-2ae4-4b26-9a04-1f80d1479112-StreamThread-2" org.apache.kafka.streams.errors.StreamsException: Deserialization exception handler is set to fail upon a deserialization error. If you would rather have the streaming pipeline continue after a deserialization error, please set the default.deserialization.exception.handler appropriately.
    at org.apache.kafka.streams.processor.internals.RecordDeserializer.deserialize(RecordDeserializer.java:74)
    at org.apache.kafka.streams.processor.internals.RecordQueue.addRawRecords(RecordQueue.java:91)
    at org.apache.kafka.streams.processor.internals.PartitionGroup.addRawRecords(PartitionGroup.java:117)
    at org.apache.kafka.streams.processor.internals.StreamTask.addRecords(StreamTask.java:549)
    at org.apache.kafka.streams.processor.internals.StreamThread.addRecordsToTasks(StreamThread.java:920)
    at org.apache.kafka.streams.processor.internals.StreamThread.runOnce(StreamThread.java:821)
    at org.apache.kafka.streams.processor.internals.StreamThread.runLoop(StreamThread.java:774)
    at org.apache.kafka.streams.processor.internals.StreamThread.run(StreamThread.java:744)
Caused by: org.apache.kafka.common.errors.SerializationException: Size of data received by LongDeserializer is not 8

Answer 1

您需要取消注释这一行：https://github.com/jaysara/KStreamAnalytics/blob/master/src/main/resources/application.properties#L19

spring.cloud.stream.bindings.policyPaidAnalytic.producer.useNativeEncoding=true

默认情况下，活页夹尝试在出站上序列化并使用application/json作为内容类型。所以，在你的情况下，它出现了json（String），这就是为什么你得到Long序列化异常。通过将上面的标志设置为true，您要求绑定器保持不变，并让Kafka Streams使用LongSerde进行本地序列化。

重新运行时，您可能希望清除主题policyAnalytic或使用新主题。

希望有所帮助。

使用spring-kakfa-stream读取KTable时出现LongDeserializer异常

1 个答案: