DLT-Konfig für `spring-consumer`, die auch mit Poison Pills umgehen kann

[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 04dc343..0360f68 100644 (file)
--- a/src/main/java/de/juplo/kafka/Application.java
+++ b/src/main/java/de/juplo/kafka/Application.java
@@ -1,61 +1,67 @@
 package de.juplo.kafka;
 
-import lombok.extern.slf4j.Slf4j;
-import org.apache.kafka.clients.consumer.Consumer;
-import org.springframework.beans.factory.annotation.Autowired;
-import org.springframework.boot.ApplicationArguments;
-import org.springframework.boot.ApplicationRunner;
+import org.apache.kafka.clients.producer.ProducerConfig;
+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.context.ConfigurableApplicationContext;
-import org.springframework.scheduling.concurrent.ThreadPoolTaskExecutor;
-import org.springframework.util.concurrent.ListenableFuture;
+import org.springframework.boot.autoconfigure.kafka.KafkaProperties;
+import org.springframework.boot.context.properties.EnableConfigurationProperties;
+import org.springframework.context.annotation.Bean;
+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.concurrent.ExecutionException;
+import java.util.Map;
 
 
 @SpringBootApplication
-@Slf4j
-public class Application implements ApplicationRunner
+@EnableConfigurationProperties({ KafkaProperties.class, ApplicationProperties.class })
+public class Application
 {
-  @Autowired
-  ThreadPoolTaskExecutor taskExecutor;
-  @Autowired
-  Consumer<?, ?> kafkaConsumer;
-  @Autowired
-  SimpleConsumer simpleConsumer;
-  @Autowired
-  ConfigurableApplicationContext context;
+  @Bean
+  public ProducerFactory<String, Object> producerFactory(
+    KafkaProperties properties)
+  {
+    Map<String, Object> map = Map.of(
+      ProducerConfig.BOOTSTRAP_SERVERS_CONFIG, properties.getBootstrapServers());
+    return new DefaultKafkaProducerFactory<>(
+      map,
+      new StringSerializer(),
+      new DelegatingByTypeSerializer(
+        Map.of(
+          byte[].class, new ByteArraySerializer(),
+          MessageAddNumber.class, new JsonSerializer<>(),
+          MessageCalculateSum.class, new JsonSerializer<>())));
+  }
 
-  ListenableFuture<Integer> consumerJob;
+  @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 SimpleConsumer");
-    consumerJob = taskExecutor.submitListenable(simpleConsumer);
-    consumerJob.addCallback(
-      exitStatus ->
-      {
-        log.info("SimpleConsumer exited normally, exit-status: {}", exitStatus);
-        SpringApplication.exit(context, () -> exitStatus);
-        },
-      t ->
-      {
-        log.error("SimpleConsumer exited abnormally!", t);
-        SpringApplication.exit(context, () -> 2);
-      });
+    return new DeadLetterPublishingRecoverer(kafkaTemplate);
   }
 
-  @PreDestroy
-  public void shutdown() throws ExecutionException, InterruptedException
+  @Bean
+  public DefaultErrorHandler errorHandler(
+    DeadLetterPublishingRecoverer recoverer)
   {
-    log.info("Signaling SimpleConsumer to quit its work");
-    kafkaConsumer.wakeup();
-    log.info("Waiting for SimpleConsumer to finish its work");
-    consumerJob.get();
-    log.info("SimpleConsumer finished its work");
+    return new DefaultErrorHandler(
+      recoverer,
+      new FixedBackOff(0l, 0l));
   }