Question

我使用this作为示例使用spring集成来读取文件，它工作正常但是当我尝试将文件发送给kafka生产者时它不起作用。我试图在互联网上查找此问题，但无法找到帮助。这是我的代码：

file：MessageProcessingIntegrationFlow.java：

@Bean
public IntegrationFlow writeToFile() {
return IntegrationFlows.from(ApplicationConfiguration.INBOUND_CHANNEL)
       .transform(m -> new StringBuilder((String)m).toString().toUpperCase())
//                .handle(fileWritingMessageHandler)
    .handle(loggingHandler())
    .handle(kafkaProducerMessageHandler())
    .get();
}



 //producing channel
@Bean(name="kafkaChannel")
public DirectChannel kafkaChannel() {
    return new DirectChannel();
}

@Bean
public DirectChannel consumingChannel() {
  return new DirectChannel();
}


    @Bean
@ServiceActivator(inputChannel = "kafkaChannel")
public MessageHandler kafkaProducerMessageHandler() {
    KafkaProducerMessageHandler<String, String> handler =
            new KafkaProducerMessageHandler<>(kafkaTemplate());
    handler.setTopicExpression(new LiteralExpression(kafkaTopic));
    handler.setMessageKeyExpression(new LiteralExpression("kafka-integration"));
    return handler;
}

@Bean
public KafkaTemplate<String, String> kafkaTemplate() {
  return new KafkaTemplate<>(producerFactory());
}

@Bean
public ProducerFactory<String, String> producerFactory() {
  return new DefaultKafkaProducerFactory<>(producerConfigs());
}

@Bean
public Map<String, Object> producerConfigs() {
  Map<String, Object> properties = new HashMap<>();
  properties.put(ProducerConfig.BOOTSTRAP_SERVERS_CONFIG, bootstrapServers);
  properties.put(ProducerConfig.KEY_SERIALIZER_CLASS_CONFIG, StringSerializer.class);
  properties.put(ProducerConfig.VALUE_SERIALIZER_CLASS_CONFIG, StringSerializer.class);
  // introduce a delay on the send to allow more messages to accumulate
  properties.put(ProducerConfig.LINGER_MS_CONFIG, 1);

  return properties;
}

//consumer configuration....
@Bean
public KafkaMessageDrivenChannelAdapter<String, String> kafkaMessageDrivenChannelAdapter() {
  KafkaMessageDrivenChannelAdapter<String, String> kafkaMessageDrivenChannelAdapter =
      new KafkaMessageDrivenChannelAdapter<>(kafkaListenerContainer());
  kafkaMessageDrivenChannelAdapter.setOutputChannel(consumingChannel());
  return kafkaMessageDrivenChannelAdapter;
}

@SuppressWarnings("unchecked")
@Bean
public ConcurrentMessageListenerContainer<String, String> kafkaListenerContainer() {
  ContainerProperties containerProps = new ContainerProperties(kafkaTopic); //set topic name
  return (ConcurrentMessageListenerContainer<String, String>) new ConcurrentMessageListenerContainer<>(
      consumerFactory(), containerProps);
}

@Bean
public ConsumerFactory<?, ?> consumerFactory() {
  return new DefaultKafkaConsumerFactory<>(consumerConfigs());
}

@Bean
public Map<String, Object> consumerConfigs() {
  Map<String, Object> properties = new HashMap<>();
  properties.put(ConsumerConfig.BOOTSTRAP_SERVERS_CONFIG, bootstrapServers);
  properties.put(ConsumerConfig.KEY_DESERIALIZER_CLASS_CONFIG, StringDeserializer.class);
  properties.put(ConsumerConfig.VALUE_DESERIALIZER_CLASS_CONFIG, StringDeserializer.class);
  properties.put(ConsumerConfig.GROUP_ID_CONFIG, "helloworld");
  // automatically reset the offset to the earliest offset
  properties.put(ConsumerConfig.AUTO_OFFSET_RESET_CONFIG, "earliest");

  return properties;
}

这是stacktrace：

 org.springframework.context.ApplicationContextException: Failed to start bean 'kafkaListenerContainer'; nested exception is java.lang.IllegalArgumentException: A org.springframework.kafka.listener.KafkaDataListener implementation must be provided
at org.springframework.context.support.DefaultLifecycleProcessor.doStart(DefaultLifecycleProcessor.java:178) ~[spring-context-4.3.12.RELEASE.jar:4.3.12.RELEASE]
at org.springframework.context.support.DefaultLifecycleProcessor.access$200(DefaultLifecycleProcessor.java:50) ~[spring-context-4.3.12.RELEASE.jar:4.3.12.RELEASE]
at org.springframework.context.support.DefaultLifecycleProcessor$LifecycleGroup.start(DefaultLifecycleProcessor.java:348) ~[spring-context-4.3.12.RELEASE.jar:4.3.12.RELEASE]
at org.springframework.context.support.DefaultLifecycleProcessor.startBeans(DefaultLifecycleProcessor.java:151) ~[spring-context-4.3.12.RELEASE.jar:4.3.12.RELEASE]
at org.springframework.context.support.DefaultLifecycleProcessor.onRefresh(DefaultLifecycleProcessor.java:114) ~[spring-context-4.3.12.RELEASE.jar:4.3.12.RELEASE]
at org.springframework.context.support.AbstractApplicationContext.finishRefresh(AbstractApplicationContext.java:880) ~[spring-context-4.3.12.RELEASE.jar:4.3.12.RELEASE]
at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:546) ~[spring-context-4.3.12.RELEASE.jar:4.3.12.RELEASE]
at org.springframework.boot.SpringApplication.refresh(SpringApplication.java:693) [spring-boot-1.5.8.RELEASE.jar:1.5.8.RELEASE]
at org.springframework.boot.SpringApplication.refreshContext(SpringApplication.java:360) [spring-boot-1.5.8.RELEASE.jar:1.5.8.RELEASE]
at org.springframework.boot.SpringApplication.run(SpringApplication.java:303) [spring-boot-1.5.8.RELEASE.jar:1.5.8.RELEASE]
at org.springframework.boot.SpringApplication.run(SpringApplication.java:1118) [spring-boot-1.5.8.RELEASE.jar:1.5.8.RELEASE]
at org.springframework.boot.SpringApplication.run(SpringApplication.java:1107) [spring-boot-1.5.8.RELEASE.jar:1.5.8.RELEASE]
at com.porterhead.Application.main(Application.java:25) [classes/:na]
 Caused by: java.lang.IllegalArgumentException: A org.springframework.kafka.listener.KafkaDataListener implementation must be provided
at org.springframework.util.Assert.isTrue(Assert.java:92) ~[spring-core-4.3.12.RELEASE.jar:4.3.12.RELEASE]
at org.springframework.kafka.listener.AbstractMessageListenerContainer.start(AbstractMessageListenerContainer.java:199) ~[spring-kafka-1.2.2.RELEASE.jar:na]
at org.springframework.context.support.DefaultLifecycleProcessor.doStart(DefaultLifecycleProcessor.java:175) ~[spring-context-4.3.12.RELEASE.jar:4.3.12.RELEASE]
... 12 common frames omitted

我不知道自己做错了什么。如果您需要更多详细信息，请告诉我。感谢。

Answer 1

KafkaProducerMessageHandler是单向组件，它不会产生回复。它只是发布到Kafka主题，并没有做任何其他事情。因此，您不能像使用handle(loggingHandler())一样继续流动。 KafkaProducerMessageHandler必须是流中的最后一个端点。与FileWritingMessageHandler AbstractReplyProducingMessageHandler不同，继续流程。

尽管如此，请考虑将来正确描述问题：预期和错误。答案是我最好的猜测，因为我知道所有这些组件的代码。

无法启动bean kafkaListenerContainer：java.lang.IllegalArgumentException

1 个答案: