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.InboundChannelAdapter;
  12 import org.springframework.integration.annotation.ServiceActivator;
  13 import org.springframework.integration.config.EnableIntegration;
  14 import org.springframework.integration.kafka.inbound.KafkaMessageSource;
  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.ConsumerProperties;
  19 import org.springframework.messaging.MessageHandler;
  20
  21
  22 @SpringBootApplication
  23 @EnableConfigurationProperties(SplitterApplicationProperties.class)
  24 @EnableIntegration
  25 public class SplitterApplication
  26 {
  27         @InboundChannelAdapter(channel = "recordings")
  28         @Bean
  29         KafkaMessageSource<String, String> source(
  30                         ConsumerFactory<String, String> cf,
  31                         SplitterApplicationProperties properties)
  32         {
  33                 return new KafkaMessageSource<>(cf, new ConsumerProperties(properties.getInputTopic()));
  34         }
  35
  36         @Bean
  37         @ServiceActivator(inputChannel = "words")
  38         MessageHandler handler(
  39                         KafkaTemplate<String, String> kafkaTemplate,
  40                         SplitterApplicationProperties properties)
  41         {
  42                 KafkaProducerMessageHandler<String, String> handler =
  43                                 new KafkaProducerMessageHandler<>(kafkaTemplate);
  44                 handler.setTopicExpression(new LiteralExpression(properties.getOutputTopic()));
  45                 final ExpressionParser parser = new SpelExpressionParser();
  46                 Expression expression = parser.parseExpression("headers['kafka_receivedMessageKey']");
  47                 handler.setMessageKeyExpression(expression);
  48                 return handler;
  49         }
  50
  51         public static void main(String[] args)
  52         {
  53                 SpringApplication.run(SplitterApplication.class, args);
  54         }
  55 }