Vereinfachte Version der auf Spring Kafka basierenden Implementierung
[demos/kafka/training] / src / main / java / de / juplo / kafka / Application.java
index de4b66d..69a9712 100644 (file)
 package de.juplo.kafka;
 
-import org.springframework.beans.factory.annotation.Autowired;
+import lombok.extern.slf4j.Slf4j;
+import org.apache.kafka.common.serialization.ByteArraySerializer;
+import org.apache.kafka.common.serialization.StringSerializer;
 import org.springframework.boot.SpringApplication;
 import org.springframework.boot.autoconfigure.SpringBootApplication;
+import org.springframework.boot.autoconfigure.kafka.KafkaProperties;
 import org.springframework.boot.context.properties.EnableConfigurationProperties;
 import org.springframework.context.annotation.Bean;
+import org.springframework.kafka.annotation.EnableKafka;
+import org.springframework.kafka.config.KafkaListenerEndpointRegistry;
+import org.springframework.kafka.core.DefaultKafkaProducerFactory;
+import org.springframework.kafka.core.KafkaOperations;
+import org.springframework.kafka.core.KafkaTemplate;
+import org.springframework.kafka.core.ProducerFactory;
+import org.springframework.kafka.listener.DeadLetterPublishingRecoverer;
+import org.springframework.kafka.listener.DefaultErrorHandler;
+import org.springframework.kafka.support.serializer.DelegatingByTypeSerializer;
+import org.springframework.kafka.support.serializer.JsonSerializer;
+import org.springframework.util.backoff.FixedBackOff;
 
-import java.util.concurrent.Executors;
+import java.util.Map;
+import java.util.Optional;
 
 
 @SpringBootApplication
-@EnableConfigurationProperties(ApplicationProperties.class)
+@Slf4j
+@EnableConfigurationProperties({ KafkaProperties.class, ApplicationProperties.class })
+@EnableKafka
 public class Application
 {
-  @Autowired
-  ApplicationProperties properties;
+  @Bean
+  public ApplicationRecordHandler applicationRecordHandler(
+      AdderResults adderResults,
+      KafkaProperties kafkaProperties,
+      ApplicationProperties applicationProperties)
+  {
+    return new ApplicationRecordHandler(
+        adderResults,
+        Optional.ofNullable(applicationProperties.getThrottle()),
+        kafkaProperties.getConsumer().getGroupId());
+  }
 
+  @Bean
+  public AdderResults adderResults()
+  {
+    return new AdderResults();
+  }
 
   @Bean
-  public EndlessConsumer consumer()
+  public ApplicationRebalanceListener rebalanceListener(
+      ApplicationRecordHandler recordHandler,
+      AdderResults adderResults,
+      StateRepository stateRepository,
+      KafkaProperties kafkaProperties)
   {
-    EndlessConsumer consumer =
-        new EndlessConsumer(
-            Executors.newFixedThreadPool(1),
-            properties.getBootstrapServer(),
-            properties.getGroupId(),
-            properties.getClientId(),
-            properties.getTopic(),
-            properties.getAutoOffsetReset());
+    return new ApplicationRebalanceListener(
+        recordHandler,
+        adderResults,
+        stateRepository,
+        kafkaProperties.getConsumer().getGroupId());
+  }
 
-    consumer.start();
+  @Bean
+  ApplicationHealthIndicator applicationHealthIndicator(
+      KafkaListenerEndpointRegistry registry,
+      KafkaProperties properties)
+  {
+    return new ApplicationHealthIndicator(
+        properties.getConsumer().getGroupId(),
+        registry);
+  }
 
-    return consumer;
+  @Bean
+  public ProducerFactory<String, Object> producerFactory(
+      KafkaProperties properties)
+  {
+    return new DefaultKafkaProducerFactory<>(
+        properties.getProducer().buildProperties(),
+        new StringSerializer(),
+        new DelegatingByTypeSerializer(
+            Map.of(
+                byte[].class, new ByteArraySerializer(),
+                MessageAddNumber.class, new JsonSerializer<>(),
+                MessageCalculateSum.class, new JsonSerializer<>())));
   }
 
+  @Bean
+  public KafkaTemplate<String, Object> kafkaTemplate(
+      ProducerFactory<String, Object> producerFactory)
+  {
+    return new KafkaTemplate<>(producerFactory);
+  }
+
+  @Bean
+  public DeadLetterPublishingRecoverer deadLetterPublishingRecoverer(
+      KafkaOperations<?, ?> kafkaTemplate)
+  {
+    return new DeadLetterPublishingRecoverer(kafkaTemplate);
+  }
+
+  @Bean
+  public DefaultErrorHandler errorHandler(
+      DeadLetterPublishingRecoverer recoverer)
+  {
+    return new DefaultErrorHandler(
+        recoverer,
+        new FixedBackOff(0l, 0l));
+  }
+
+
   public static void main(String[] args)
   {
     SpringApplication.run(Application.class, args);