Vereinfachte Version der auf Spring Kafka basierenden Implementierung

[demos/kafka/training] / src / main / java / de / juplo / kafka / Application.java

diff --git a/src/main/java/de/juplo/kafka/Application.java b/src/main/java/de/juplo/kafka/Application.java
index a4d9aeb..69a9712 100644 (file)
--- a/src/main/java/de/juplo/kafka/Application.java
+++ b/src/main/java/de/juplo/kafka/Application.java
@@ -1,46 +1,112 @@
 package de.juplo.kafka;
 
 import lombok.extern.slf4j.Slf4j;
-import org.springframework.beans.factory.annotation.Autowired;
-import org.springframework.boot.ApplicationArguments;
-import org.springframework.boot.ApplicationRunner;
+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 javax.annotation.PreDestroy;
+import java.util.Map;
+import java.util.Optional;
 
 
 @SpringBootApplication
 @Slf4j
-public class Application implements ApplicationRunner
+@EnableConfigurationProperties({ KafkaProperties.class, ApplicationProperties.class })
+@EnableKafka
+public class Application
 {
-  @Autowired
-  EndlessConsumer endlessConsumer;
+  @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 ApplicationRebalanceListener rebalanceListener(
+      ApplicationRecordHandler recordHandler,
+      AdderResults adderResults,
+      StateRepository stateRepository,
+      KafkaProperties kafkaProperties)
+  {
+    return new ApplicationRebalanceListener(
+        recordHandler,
+        adderResults,
+        stateRepository,
+        kafkaProperties.getConsumer().getGroupId());
+  }
 
+  @Bean
+  ApplicationHealthIndicator applicationHealthIndicator(
+      KafkaListenerEndpointRegistry registry,
+      KafkaProperties properties)
+  {
+    return new ApplicationHealthIndicator(
+        properties.getConsumer().getGroupId(),
+        registry);
+  }
+
+  @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);
+  }
 
-  @Override
-  public void run(ApplicationArguments args) throws Exception
+  @Bean
+  public DeadLetterPublishingRecoverer deadLetterPublishingRecoverer(
+      KafkaOperations<?, ?> kafkaTemplate)
   {
-    log.info("Starting EndlessConsumer");
-    endlessConsumer.start();
+    return new DeadLetterPublishingRecoverer(kafkaTemplate);
   }
 
-  @PreDestroy
-  public void shutdown()
+  @Bean
+  public DefaultErrorHandler errorHandler(
+      DeadLetterPublishingRecoverer recoverer)
   {
-    try
-    {
-      log.info("Stopping EndlessConsumer");
-      endlessConsumer.stop();
-    }
-    catch (IllegalStateException e)
-    {
-      log.info("Was already stopped: {}", e.toString());
-    }
-    catch (Exception e)
-    {
-      log.error("Unexpected exception while stopping EndlessConsumer: {}", e);
-    }
+    return new DefaultErrorHandler(
+        recoverer,
+        new FixedBackOff(0l, 0l));
   }