Kafka批处理侦听器不正确的反序列化消息答案

【问题标题】：Kafka batch listener incorrect deserializing messageKafka批处理侦听器不正确的反序列化消息
【发布时间】：2019-12-10 03:26:31
【问题描述】：

我正在使用具有以下配置的批处理侦听，但我的消息反序列化错误：

@KafkaListener(
    id = "${kafka.buyers.product-sales-pricing.id}",
    topics = "${kafka.buyers.product-sales-pricing.topic}",
    groupId = "${kafka.buyers.group-id}",
    concurrency = "${kafka.buyers.concurrency}"
)
public void listen( @Payload List<String> messages,
    @Header( KafkaHeaders.RECEIVED_PARTITION_ID ) List<Integer> partitions,
    @Header( KafkaHeaders.OFFSET ) List<Long> offsets ) throws IOException
{}

在 yml 中：

spring:
  kafka:
    bootstrapServers: localhost:29092
    consumer:
      enable-auto-commit: false
      autoOffsetReset: earliest
      keyDeserializer: org.apache.kafka.common.serialization.StringDeserializer
      valueDeserializer: org.apache.kafka.common.serialization.StringDeserializer #spring message converter will take care of deserialization
      max-poll-records: 5

使用上面的方法，我正在轮询 5 条消息，但收到超过 100 条消息，当我检查它时，将消息反序列化为列表中的多个。

我检查了我的投票配置不工作。任何人都可以建议我解决方案

以下是我的日志：

2019-08-01 20:10:42.777  INFO 2823 --- [           main] o.a.k.clients.consumer.ConsumerConfig    : ConsumerConfig values: 
    auto.commit.interval.ms = 5000
    auto.offset.reset = earliest
    bootstrap.servers = [localhost:29092]
    check.crcs = true
    client.id = 
    connections.max.idle.ms = 540000
    default.api.timeout.ms = 60000
    enable.auto.commit = false
    exclude.internal.topics = true
    fetch.max.bytes = 52428800
    fetch.max.wait.ms = 500
    fetch.min.bytes = 1
    group.id = kafka-buyers-consumer-group1
    heartbeat.interval.ms = 3000
    interceptor.classes = []
    internal.leave.group.on.close = true
    isolation.level = read_uncommitted
    key.deserializer = class org.apache.kafka.common.serialization.StringDeserializer
    max.partition.fetch.bytes = 1048576
    max.poll.interval.ms = 300000
    max.poll.records = 5
    metadata.max.age.ms = 300000
    metric.reporters = []
    metrics.num.samples = 2
    metrics.recording.level = INFO
    metrics.sample.window.ms = 30000
    partition.assignment.strategy = [class org.apache.kafka.clients.consumer.RangeAssignor]
    receive.buffer.bytes = 65536
    reconnect.backoff.max.ms = 1000
    reconnect.backoff.ms = 50
    request.timeout.ms = 30000
    retry.backoff.ms = 100
    sasl.client.callback.handler.class = null
    sasl.jaas.config = null
    sasl.kerberos.kinit.cmd = /usr/bin/kinit
    sasl.kerberos.min.time.before.relogin = 60000
    sasl.kerberos.service.name = null
    sasl.kerberos.ticket.renew.jitter = 0.05
    sasl.kerberos.ticket.renew.window.factor = 0.8
    sasl.login.callback.handler.class = null
    sasl.login.class = null
    sasl.login.refresh.buffer.seconds = 300
    sasl.login.refresh.min.period.seconds = 60
    sasl.login.refresh.window.factor = 0.8
    sasl.login.refresh.window.jitter = 0.05
    sasl.mechanism = GSSAPI
    security.protocol = PLAINTEXT
    send.buffer.bytes = 131072
    session.timeout.ms = 10000
    ssl.cipher.suites = null
    ssl.enabled.protocols = [TLSv1.2, TLSv1.1, TLSv1]
    ssl.endpoint.identification.algorithm = https
    ssl.key.password = null
    ssl.keymanager.algorithm = SunX509
    ssl.keystore.location = null
    ssl.keystore.password = null
    ssl.keystore.type = JKS
    ssl.protocol = TLS
    ssl.provider = null
    ssl.secure.random.implementation = null
    ssl.trustmanager.algorithm = PKIX
    ssl.truststore.location = null
    ssl.truststore.password = null
    ssl.truststore.type = JKS
    value.deserializer = class org.apache.kafka.common.serialization.StringDeserializer

【问题讨论】：

你能展示一些示例输入和输出
输入是一个 json 消息，单个消息分成列表。这有帮助吗？
@Deadpool 请查找输出和配置日志
@Deadpool 当我将列表从消费者更改为字符串对象时，这对我来说很好
@ankit 我认为问题出在配置中，您的问题标题与您的描述不匹配。

标签： spring-boot kafka-consumer-api

【解决方案1】：

在您的情况下，您错过了批量侦听的一项配置：

spring:
  kafka:
    listener:
    type: BATCH # this configuration is required in spring boot application without this spring boot return single message(without batch)
    fetch-min-size: 10 # without this you will get 1 message some time but this is optional in your case.

我敢打赌，如果您从 kafkaListner 类中删除 List，您的配置将起作用。

希望对你有所帮助。

【讨论】：