juplo.de Git - demos/kafka/wordcount/blob - src/main/java/de/juplo/kafka/wordcount/splitter/SplitterApplication.java

   1 package de.juplo.kafka.wordcount.splitter;
   2
   3 import org.springframework.boot.SpringApplication;
   4 import org.springframework.boot.autoconfigure.SpringBootApplication;
   5 import org.springframework.boot.context.properties.EnableConfigurationProperties;
   6 import org.springframework.context.annotation.Bean;
   7 import org.springframework.expression.Expression;
   8 import org.springframework.expression.ExpressionParser;
   9 import org.springframework.expression.common.LiteralExpression;
  10 import org.springframework.expression.spel.standard.SpelExpressionParser;
  11 import org.springframework.integration.annotation.ServiceActivator;
  12 import org.springframework.integration.config.EnableIntegration;
  13 import org.springframework.integration.core.MessageProducer;
  14 import org.springframework.integration.kafka.inbound.KafkaMessageDrivenChannelAdapter;
  15 import org.springframework.integration.kafka.outbound.KafkaProducerMessageHandler;
  16 import org.springframework.kafka.core.ConsumerFactory;
  17 import org.springframework.kafka.core.KafkaTemplate;
  18 import org.springframework.kafka.listener.ContainerProperties;
  19 import org.springframework.kafka.listener.KafkaMessageListenerContainer;
  20 import org.springframework.messaging.MessageHandler;
  21
  22
  23 @SpringBootApplication
  24 @EnableConfigurationProperties(SplitterApplicationProperties.class)
  25 @EnableIntegration
  26 public class SplitterApplication
  27 {
  28         @Bean
  29         MessageProducer messageProducer(
  30                         KafkaMessageListenerContainer<String, String> messageListenerContainer)
  31         {
  32                 KafkaMessageDrivenChannelAdapter<String, String> adapter =
  33                                 new KafkaMessageDrivenChannelAdapter(messageListenerContainer);
  34                 adapter.setOutputChannelName("recordings");
  35                 return adapter;
  36         }
  37
  38         @Bean
  39         KafkaMessageListenerContainer<String, String> messageListenerContainer(
  40                         ConsumerFactory<String,String> consumerFactory,
  41                         SplitterApplicationProperties properties)
  42         {
  43                 return
  44                                 new KafkaMessageListenerContainer<>(
  45                                                 consumerFactory,
  46                                                 new ContainerProperties(properties.getInputTopic()));
  47         }
  48
  49         @Bean
  50         @ServiceActivator(inputChannel = "words")
  51         MessageHandler handler(
  52                         KafkaTemplate<String, String> kafkaTemplate,
  53                         SplitterApplicationProperties properties)
  54         {
  55                 KafkaProducerMessageHandler<String, String> handler =
  56                                 new KafkaProducerMessageHandler<>(kafkaTemplate);
  57                 handler.setTopicExpression(new LiteralExpression(properties.getOutputTopic()));
  58                 final ExpressionParser parser = new SpelExpressionParser();
  59                 Expression expression = parser.parseExpression("headers['kafka_receivedMessageKey']");
  60                 handler.setMessageKeyExpression(expression);
  61                 return handler;
  62         }
  63
  64         public static void main(String[] args)
  65         {
  66                 SpringApplication.run(SplitterApplication.class, args);
  67         }
  68 }