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 5226d6b..69a9712 100644 (file)
--- a/src/main/java/de/juplo/kafka/Application.java
+++ b/src/main/java/de/juplo/kafka/Application.java
@@ -1,52 +1,112 @@
 package de.juplo.kafka;
 
-import org.apache.kafka.clients.consumer.KafkaConsumer;
-import org.apache.kafka.common.serialization.LongDeserializer;
-import org.apache.kafka.common.serialization.StringDeserializer;
+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.Properties;
-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
 {
   @Bean
-  public EndlessConsumer endlessConsumer(
-      KafkaConsumer<String, String> kafkaConsumer,
-      ApplicationProperties properties)
+  public ApplicationRecordHandler applicationRecordHandler(
+      AdderResults adderResults,
+      KafkaProperties kafkaProperties,
+      ApplicationProperties applicationProperties)
   {
-    EndlessConsumer consumer =
-        new EndlessConsumer(
-            Executors.newFixedThreadPool(1),
-            properties.getClientId(),
-            properties.getTopic(),
-            kafkaConsumer);
+    return new ApplicationRecordHandler(
+        adderResults,
+        Optional.ofNullable(applicationProperties.getThrottle()),
+        kafkaProperties.getConsumer().getGroupId());
+  }
 
-    consumer.start();
+  @Bean
+  public AdderResults adderResults()
+  {
+    return new AdderResults();
+  }
 
-    return consumer;
+  @Bean
+  public ApplicationRebalanceListener rebalanceListener(
+      ApplicationRecordHandler recordHandler,
+      AdderResults adderResults,
+      StateRepository stateRepository,
+      KafkaProperties kafkaProperties)
+  {
+    return new ApplicationRebalanceListener(
+        recordHandler,
+        adderResults,
+        stateRepository,
+        kafkaProperties.getConsumer().getGroupId());
   }
 
-  @Bean(destroyMethod = "close")
-  public KafkaConsumer<String, String> kafkaConsumer(ApplicationProperties properties)
+  @Bean
+  ApplicationHealthIndicator applicationHealthIndicator(
+      KafkaListenerEndpointRegistry registry,
+      KafkaProperties properties)
   {
-    Properties props = new Properties();
+    return new ApplicationHealthIndicator(
+        properties.getConsumer().getGroupId(),
+        registry);
+  }
 
-    props.put("bootstrap.servers", properties.getBootstrapServer());
-    props.put("group.id", properties.getGroupId());
-    props.put("client.id", properties.getClientId());
-    props.put("auto.offset.reset", properties.getAutoOffsetReset());
-    props.put("metadata.max.age.ms", "1000");
-    props.put("key.deserializer", StringDeserializer.class.getName());
-    props.put("value.deserializer", LongDeserializer.class.getName());
+  @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<>())));
+  }
 
-    return new KafkaConsumer<>(props);
+  @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));
   }