Service ergänzt, der das Dead-Letter-Topic ausliest

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

diff --git a/src/main/java/de/juplo/kafka/ApplicationConfiguration.java b/src/main/java/de/juplo/kafka/ApplicationConfiguration.java
index 523707f..b5f6187 100644 (file)
--- a/src/main/java/de/juplo/kafka/ApplicationConfiguration.java
+++ b/src/main/java/de/juplo/kafka/ApplicationConfiguration.java
@@ -1,17 +1,25 @@
 package de.juplo.kafka;
 
-import org.apache.kafka.clients.consumer.KafkaConsumer;
-import org.apache.kafka.common.serialization.StringDeserializer;
+import org.apache.kafka.common.serialization.ByteArraySerializer;
+import org.apache.kafka.common.serialization.StringSerializer;
 import org.springframework.boot.autoconfigure.kafka.KafkaProperties;
 import org.springframework.boot.context.properties.EnableConfigurationProperties;
 import org.springframework.context.annotation.Bean;
 import org.springframework.context.annotation.Configuration;
-import org.springframework.kafka.support.serializer.JsonDeserializer;
 
+import java.util.Map;
 import java.util.Optional;
-import java.util.Properties;
-import java.util.concurrent.ExecutorService;
-import java.util.concurrent.Executors;
+
+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;
 
 
 @Configuration
@@ -19,7 +27,7 @@ import java.util.concurrent.Executors;
 public class ApplicationConfiguration
 {
   @Bean
-  public ApplicationRecordHandler recordHandler(
+  public ApplicationRecordHandler applicationRecordHandler(
       AdderResults adderResults,
       KafkaProperties kafkaProperties,
       ApplicationProperties applicationProperties)
@@ -41,8 +49,7 @@ public class ApplicationConfiguration
       ApplicationRecordHandler recordHandler,
       AdderResults adderResults,
       StateRepository stateRepository,
-      KafkaProperties kafkaProperties,
-      ApplicationProperties applicationProperties)
+      KafkaProperties kafkaProperties)
   {
     return new ApplicationRebalanceListener(
         recordHandler,
@@ -52,49 +59,52 @@ public class ApplicationConfiguration
   }
 
   @Bean
-  public EndlessConsumer<String, Message> endlessConsumer(
-      KafkaConsumer<String, Message> kafkaConsumer,
-      ExecutorService executor,
-      ApplicationRebalanceListener rebalanceListener,
-      ApplicationRecordHandler recordHandler,
+  public EndlessConsumer endlessConsumer(
+      RecordHandler recordHandler,
       KafkaProperties kafkaProperties,
-      ApplicationProperties applicationProperties)
+      KafkaListenerEndpointRegistry endpointRegistry)
   {
     return
-        new EndlessConsumer<>(
-            executor,
+        new EndlessConsumer(
             kafkaProperties.getClientId(),
-            applicationProperties.getTopic(),
-            kafkaConsumer,
-            rebalanceListener,
+            endpointRegistry,
             recordHandler);
   }
 
   @Bean
-  public ExecutorService executor()
+  public ProducerFactory<String, Object> producerFactory(
+      KafkaProperties properties)
   {
-    return Executors.newSingleThreadExecutor();
+    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(destroyMethod = "close")
-  public KafkaConsumer<String, Message> kafkaConsumer(KafkaProperties kafkaProperties)
+  @Bean
+  public KafkaTemplate<String, Object> kafkaTemplate(
+      ProducerFactory<String, Object> producerFactory)
   {
-    Properties props = new Properties();
+    return new KafkaTemplate<>(producerFactory);
+  }
 
-    props.put("bootstrap.servers", kafkaProperties.getBootstrapServers());
-    props.put("partition.assignment.strategy", "org.apache.kafka.clients.consumer.StickyAssignor");
-    props.put("group.id", kafkaProperties.getConsumer().getGroupId());
-    props.put("client.id", kafkaProperties.getClientId());
-    props.put("auto.offset.reset", kafkaProperties.getConsumer().getAutoOffsetReset());
-    props.put("auto.commit.interval.ms", (int)kafkaProperties.getConsumer().getAutoCommitInterval().toMillis());
-    props.put("metadata.max.age.ms", kafkaProperties.getConsumer().getProperties().get("metadata.max.age.ms"));
-    props.put("key.deserializer", StringDeserializer.class.getName());
-    props.put("value.deserializer", JsonDeserializer.class.getName());
-    props.put(JsonDeserializer.TRUSTED_PACKAGES, "de.juplo.kafka");
-    props.put(JsonDeserializer.TYPE_MAPPINGS,
-      Message.Type.ADD + ":" + MessageAddNumber.class.getName() + "," +
-      Message.Type.CALC + ":" + MessageCalculateSum.class.getName());
+  @Bean
+  public DeadLetterPublishingRecoverer deadLetterPublishingRecoverer(
+      KafkaOperations<?, ?> kafkaTemplate)
+  {
+    return new DeadLetterPublishingRecoverer(kafkaTemplate);
+  }
 
-    return new KafkaConsumer<>(props);
+  @Bean
+  public DefaultErrorHandler errorHandler(
+      DeadLetterPublishingRecoverer recoverer)
+  {
+    return new DefaultErrorHandler(
+        recoverer,
+        new FixedBackOff(0l, 0l));
   }
 }