From 8d0ef2423c0f6ef6a439b98a1d9b1b1a64d89d45 Mon Sep 17 00:00:00 2001
From: Kai Moritz <kai@juplo.de>
Date: Mon, 18 Jul 2022 18:09:41 +0200
Subject: [PATCH] splitter: 1.0.0-spring-ingetration - kafka-backed channels

* This configuration uses `SubscribableKafkaChannel` to configure
  kafka-backed channels for the message-channels `recordings` and `words`.
* Since the header `kafka_messageKey` is not set, the messages are send
  with `null`-keys. Hence, the order of the messages will be lost for
  topics with more than one partition.
---
 .../splitter/SplitterApplication.java         | 25 +++++++++++++++++++
 1 file changed, 25 insertions(+)

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 8bd928b..7087ed1 100644
--- a/src/main/java/de/juplo/kafka/wordcount/splitter/SplitterApplication.java
+++ b/src/main/java/de/juplo/kafka/wordcount/splitter/SplitterApplication.java
@@ -21,6 +21,9 @@ import org.springframework.kafka.core.ConsumerFactory;
 import org.springframework.kafka.core.KafkaTemplate;
 import org.springframework.kafka.listener.ContainerProperties;
 import org.springframework.kafka.listener.KafkaMessageListenerContainer;
+import org.springframework.integration.kafka.channel.SubscribableKafkaChannel;
+import org.springframework.kafka.config.KafkaListenerContainerFactory;
+import org.springframework.kafka.listener.AbstractMessageListenerContainer;
 import org.springframework.messaging.MessageHandler;
 
 import java.util.HashMap;
@@ -67,6 +70,17 @@ public class SplitterApplication
 						new ContainerProperties(properties.getInputTopic()));
 	}
 
+	@Bean
+	SubscribableKafkaChannel recordings(
+			KafkaTemplate<String, String> kafkaTemplate,
+			KafkaListenerContainerFactory<AbstractMessageListenerContainer<String, String>> containerFactory)
+	{
+		SubscribableKafkaChannel channel =
+				new SubscribableKafkaChannel(kafkaTemplate, containerFactory, "channel-recordings");
+		channel.setGroupId("recordings");
+		return channel;
+	}
+
 	@Bean
 	@ServiceActivator(inputChannel = "words")
 	MessageHandler handler(
@@ -82,6 +96,17 @@ public class SplitterApplication
 		return handler;
 	}
 
+	@Bean
+	SubscribableKafkaChannel words(
+			KafkaTemplate<String, String> kafkaTemplate,
+			KafkaListenerContainerFactory<AbstractMessageListenerContainer<String, String>> containerFactory)
+	{
+		SubscribableKafkaChannel channel =
+				new SubscribableKafkaChannel(kafkaTemplate, containerFactory, "channel-words");
+		channel.setGroupId("words");
+		return channel;
+	}
+
 	public static void main(String[] args)
 	{
 		SpringApplication.run(SplitterApplication.class, args);
-- 
2.20.1