From 9f2fda277bdd947461dc5b6dd350c29944fb43c3 Mon Sep 17 00:00:00 2001
From: Kai Moritz <kai@juplo.de>
Date: Sun, 9 Jun 2024 10:29:23 +0200
Subject: [PATCH] query: 1.0.6 - Refined `QueryApplicationConfiguration` --
 moved lifecycle-handling of the streams-processor into the config-class

---
 .../query/QueryApplicationConfiguration.java  | 26 ++++++++++++++++---
 .../wordcount/query/QueryStreamProcessor.java | 19 +-------------
 2 files changed, 23 insertions(+), 22 deletions(-)

diff --git a/src/main/java/de/juplo/kafka/wordcount/query/QueryApplicationConfiguration.java b/src/main/java/de/juplo/kafka/wordcount/query/QueryApplicationConfiguration.java
index 0e30e74..b546b8c 100644
--- a/src/main/java/de/juplo/kafka/wordcount/query/QueryApplicationConfiguration.java
+++ b/src/main/java/de/juplo/kafka/wordcount/query/QueryApplicationConfiguration.java
@@ -1,10 +1,12 @@
 package de.juplo.kafka.wordcount.query;
 
 import com.fasterxml.jackson.databind.ObjectMapper;
+import lombok.extern.slf4j.Slf4j;
 import org.apache.kafka.clients.consumer.ConsumerConfig;
 import org.apache.kafka.common.serialization.Serdes;
 import org.apache.kafka.streams.StreamsConfig;
 import org.apache.kafka.streams.state.HostInfo;
+import org.springframework.boot.SpringApplication;
 import org.springframework.boot.autoconfigure.web.ServerProperties;
 import org.springframework.boot.context.properties.EnableConfigurationProperties;
 import org.springframework.context.ConfigurableApplicationContext;
@@ -15,10 +17,14 @@ import java.io.IOException;
 import java.net.InetSocketAddress;
 import java.net.Socket;
 import java.util.Properties;
+import java.util.concurrent.CompletableFuture;
+
+import static org.apache.kafka.streams.errors.StreamsUncaughtExceptionHandler.StreamThreadExceptionResponse.SHUTDOWN_CLIENT;
 
 
 @Configuration
 @EnableConfigurationProperties(QueryApplicationProperties.class)
+@Slf4j
 public class QueryApplicationConfiguration
 {
 	@Bean
@@ -74,7 +80,7 @@ public class QueryApplicationConfiguration
 		return props;
 	}
 
-	@Bean
+	@Bean(initMethod = "start", destroyMethod = "stop")
 	public QueryStreamProcessor streamProcessor(
 			Properties streamProcessorProperties,
 			HostInfo applicationServer,
@@ -82,12 +88,24 @@ public class QueryApplicationConfiguration
 			ObjectMapper mapper,
 			ConfigurableApplicationContext context)
 	{
-		return new QueryStreamProcessor(
+		QueryStreamProcessor streamProcessor = new QueryStreamProcessor(
 				streamProcessorProperties,
 				applicationServer,
 				applicationProperties.getUsersInputTopic(),
 				applicationProperties.getRankingInputTopic(),
-				mapper,
-				context);
+				mapper);
+
+		streamProcessor.streams.setUncaughtExceptionHandler((Throwable e) ->
+		{
+			log.error("Unexpected error!", e);
+			CompletableFuture.runAsync(() ->
+			{
+				log.info("Stopping application...");
+				SpringApplication.exit(context, () -> 1);
+			});
+			return SHUTDOWN_CLIENT;
+		});
+
+		return streamProcessor;
 	}
 }
diff --git a/src/main/java/de/juplo/kafka/wordcount/query/QueryStreamProcessor.java b/src/main/java/de/juplo/kafka/wordcount/query/QueryStreamProcessor.java
index 886c8cf..2d3d4c8 100644
--- a/src/main/java/de/juplo/kafka/wordcount/query/QueryStreamProcessor.java
+++ b/src/main/java/de/juplo/kafka/wordcount/query/QueryStreamProcessor.java
@@ -16,15 +16,10 @@ import org.apache.kafka.streams.kstream.Materialized;
 import org.apache.kafka.streams.state.HostInfo;
 import org.apache.kafka.streams.state.QueryableStoreTypes;
 import org.apache.kafka.streams.state.ReadOnlyKeyValueStore;
-import org.springframework.boot.SpringApplication;
-import org.springframework.context.ConfigurableApplicationContext;
 
 import java.net.URI;
 import java.util.Optional;
 import java.util.Properties;
-import java.util.concurrent.CompletableFuture;
-
-import static org.apache.kafka.streams.errors.StreamsUncaughtExceptionHandler.StreamThreadExceptionResponse.SHUTDOWN_CLIENT;
 
 
 @Slf4j
@@ -42,8 +37,7 @@ public class QueryStreamProcessor
 			HostInfo applicationServer,
 			String usersInputTopic,
 			String rankingInputTopic,
-			ObjectMapper mapper,
-			ConfigurableApplicationContext context)
+			ObjectMapper mapper)
 	{
 		StreamsBuilder builder = new StreamsBuilder();
 
@@ -72,17 +66,6 @@ public class QueryStreamProcessor
 				.toTable(Materialized.as(storeName));
 
 		streams = new KafkaStreams(builder.build(), props);
-		streams.setUncaughtExceptionHandler((Throwable e) ->
-		{
-			log.error("Unexpected error!", e);
-			CompletableFuture.runAsync(() ->
-			{
-				log.info("Stopping application...");
-				SpringApplication.exit(context, () -> 1);
-			});
-			return SHUTDOWN_CLIENT;
-		});
-
 		hostInfo = applicationServer;
 		storeParameters = StoreQueryParameters.fromNameAndType(storeName, QueryableStoreTypes.keyValueStore());;
 		this.mapper = mapper;
-- 
2.20.1