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.beans.factory.annotation.Value;
   4 import org.springframework.boot.SpringApplication;
   5 import org.springframework.boot.autoconfigure.SpringBootApplication;
   6 import org.springframework.boot.context.properties.EnableConfigurationProperties;
   7 import org.springframework.context.annotation.Bean;
   8 import org.springframework.expression.Expression;
   9 import org.springframework.expression.ExpressionParser;
  10 import org.springframework.expression.common.LiteralExpression;
  11 import org.springframework.expression.spel.standard.SpelExpressionParser;
  12 import org.springframework.integration.annotation.ServiceActivator;
  13 import org.springframework.integration.config.EnableIntegration;
  14 import org.springframework.integration.kafka.channel.SubscribableKafkaChannel;
  15 import org.springframework.integration.kafka.outbound.KafkaProducerMessageHandler;
  16 import org.springframework.kafka.config.KafkaListenerContainerFactory;
  17 import org.springframework.kafka.core.KafkaTemplate;
  18 import org.springframework.kafka.listener.AbstractMessageListenerContainer;
  19 import org.springframework.messaging.MessageHandler;
  20 import org.springframework.messaging.SubscribableChannel;
  21
  22
  23 @SpringBootApplication
  24 @EnableConfigurationProperties(SplitterApplicationProperties.class)
  25 @EnableIntegration
  26 public class SplitterApplication
  27 {
  28         @Bean
  29         SubscribableChannel recordings(
  30                         KafkaTemplate<String, String> kafkaTemplate,
  31                         KafkaListenerContainerFactory<AbstractMessageListenerContainer<String, String>> containerFactory,
  32                         SplitterApplicationProperties properties,
  33                         @Value("${spring.kafka.consumer.group-id}") String groupId)
  34         {
  35                 SubscribableKafkaChannel channel =
  36                                 new SubscribableKafkaChannel(kafkaTemplate, containerFactory, properties.getInputTopic());
  37                 channel.setGroupId(groupId);
  38                 return channel;
  39         }
  40
  41         @Bean
  42         @ServiceActivator(inputChannel = "words")
  43         MessageHandler handler(
  44                         KafkaTemplate<String, String> kafkaTemplate,
  45                         SplitterApplicationProperties properties)
  46         {
  47                 KafkaProducerMessageHandler<String, String> handler =
  48                                 new KafkaProducerMessageHandler<>(kafkaTemplate);
  49                 handler.setTopicExpression(new LiteralExpression(properties.getOutputTopic()));
  50                 final ExpressionParser parser = new SpelExpressionParser();
  51                 Expression expression = parser.parseExpression("headers['kafka_receivedMessageKey']");
  52                 handler.setMessageKeyExpression(expression);
  53                 return handler;
  54         }
  55
  56         public static void main(String[] args)
  57         {
  58                 SpringApplication.run(SplitterApplication.class, args);
  59         }
  60 }