From 6ed97946e9e3d4e94a6ec0cc05dc257f0558bae5 Mon Sep 17 00:00:00 2001
From: Kai Moritz <kai@juplo.de>
Date: Sun, 17 Jul 2022 19:03:18 +0200
Subject: [PATCH] splitter: 1.0.0-spring-ingetration - using a channel backed
 by Kafka

* Instead of the `@InboundChannelAdapter`, a `SubscribableKafkaChanel`
  could be used.
* But in the given setup, this is kind of a dirty hack, because with this
  konfiguration the intentionally read-only input-channel becomes writable
  in Spring Integration.
---
 .../splitter/SplitterApplication.java         | 23 +++++++++++--------
 1 file changed, 14 insertions(+), 9 deletions(-)

diff --git a/src/main/java/de/juplo/kafka/wordcount/splitter/SplitterApplication.java b/src/main/java/de/juplo/kafka/wordcount/splitter/SplitterApplication.java
index 246fffd..eeeeb39 100644
--- a/src/main/java/de/juplo/kafka/wordcount/splitter/SplitterApplication.java
+++ b/src/main/java/de/juplo/kafka/wordcount/splitter/SplitterApplication.java
@@ -1,5 +1,6 @@
 package de.juplo.kafka.wordcount.splitter;
 
+import org.springframework.beans.factory.annotation.Value;
 import org.springframework.boot.SpringApplication;
 import org.springframework.boot.autoconfigure.SpringBootApplication;
 import org.springframework.boot.context.properties.EnableConfigurationProperties;
@@ -8,15 +9,15 @@ import org.springframework.expression.Expression;
 import org.springframework.expression.ExpressionParser;
 import org.springframework.expression.common.LiteralExpression;
 import org.springframework.expression.spel.standard.SpelExpressionParser;
-import org.springframework.integration.annotation.InboundChannelAdapter;
 import org.springframework.integration.annotation.ServiceActivator;
 import org.springframework.integration.config.EnableIntegration;
-import org.springframework.integration.kafka.inbound.KafkaMessageSource;
+import org.springframework.integration.kafka.channel.SubscribableKafkaChannel;
 import org.springframework.integration.kafka.outbound.KafkaProducerMessageHandler;
-import org.springframework.kafka.core.ConsumerFactory;
+import org.springframework.kafka.config.KafkaListenerContainerFactory;
 import org.springframework.kafka.core.KafkaTemplate;
-import org.springframework.kafka.listener.ConsumerProperties;
+import org.springframework.kafka.listener.AbstractMessageListenerContainer;
 import org.springframework.messaging.MessageHandler;
+import org.springframework.messaging.SubscribableChannel;
 
 
 @SpringBootApplication
@@ -24,13 +25,17 @@ import org.springframework.messaging.MessageHandler;
 @EnableIntegration
 public class SplitterApplication
 {
-	@InboundChannelAdapter(channel = "recordings")
 	@Bean
-	KafkaMessageSource<String, String> source(
-			ConsumerFactory<String, String> cf,
-			SplitterApplicationProperties properties)
+	SubscribableChannel recordings(
+			KafkaTemplate<String, String> kafkaTemplate,
+			KafkaListenerContainerFactory<AbstractMessageListenerContainer<String, String>> containerFactory,
+			SplitterApplicationProperties properties,
+			@Value("${spring.kafka.consumer.group-id}") String groupId)
 	{
-		return new KafkaMessageSource<>(cf, new ConsumerProperties(properties.getInputTopic()));
+		SubscribableKafkaChannel channel =
+				new SubscribableKafkaChannel(kafkaTemplate, containerFactory, properties.getInputTopic());
+		channel.setGroupId(groupId);
+		return channel;
 	}
 
 	@Bean
-- 
2.20.1