From: Kai Moritz <kai@juplo.de>
Date: Thu, 30 May 2024 09:01:27 +0000 (+0200)
Subject: top10: 1.2.1 - (GREEN) Made the aggregation state accessible
X-Git-Tag: top10-1.2.1~15
X-Git-Url: http://juplo.de/gitweb/?a=commitdiff_plain;h=9e0ee342b531e7cfcddfe2e34390807802725a14;p=demos%2Fkafka%2Fwordcount

top10: 1.2.1 - (GREEN) Made the aggregation state accessible

* The assertion, regarding the expected state, is true for both tests.
* The assertion, regarding the expected messages, ix only true for the
  test that is based on the `TopologyTestDriver`.
* _This highlights the need for an additional integration test to avoid
  misinterpretation of the results of tests, that are based on the
  ``TopologyTestDriver``.
* _Note,_ that the assertion, regarding the expected state, works as
  well in the `Top10ApplicationIT`, if the output buffering is enabled,
  because the changed state becomes visible immediately.
* The buffering ist still turned of, so that the disabled test can be
  run in IntelliJ to comprehend, that the assertion is actually false.
---

diff --git a/src/main/java/de/juplo/kafka/wordcount/top10/Top10ApplicationConfiguration.java b/src/main/java/de/juplo/kafka/wordcount/top10/Top10ApplicationConfiguration.java
index 000db01..6e1f93f 100644
--- a/src/main/java/de/juplo/kafka/wordcount/top10/Top10ApplicationConfiguration.java
+++ b/src/main/java/de/juplo/kafka/wordcount/top10/Top10ApplicationConfiguration.java
@@ -3,6 +3,8 @@ package de.juplo.kafka.wordcount.top10;
 import lombok.extern.slf4j.Slf4j;
 import org.apache.kafka.clients.consumer.ConsumerConfig;
 import org.apache.kafka.streams.StreamsConfig;
+import org.apache.kafka.streams.state.KeyValueBytesStoreSupplier;
+import org.apache.kafka.streams.state.Stores;
 import org.springframework.boot.SpringApplication;
 import org.springframework.boot.context.properties.EnableConfigurationProperties;
 import org.springframework.context.ConfigurableApplicationContext;
@@ -55,12 +57,14 @@ public class Top10ApplicationConfiguration
 	public Top10StreamProcessor streamProcessor(
 			Top10ApplicationProperties applicationProperties,
 			Properties streamProcessorProperties,
+			KeyValueBytesStoreSupplier storeSupplier,
 			ConfigurableApplicationContext context)
 	{
 		Top10StreamProcessor streamProcessor = new Top10StreamProcessor(
 				applicationProperties.getInputTopic(),
 				applicationProperties.getOutputTopic(),
-				streamProcessorProperties);
+				streamProcessorProperties,
+				storeSupplier);
 
 		streamProcessor.streams.setUncaughtExceptionHandler((Throwable e) ->
 		{
@@ -75,4 +79,10 @@ public class Top10ApplicationConfiguration
 
 		return streamProcessor;
 	}
+
+	@Bean
+	public KeyValueBytesStoreSupplier storeSupplier()
+	{
+		return Stores.persistentKeyValueStore("top10");
+	}
 }
diff --git a/src/main/java/de/juplo/kafka/wordcount/top10/Top10StreamProcessor.java b/src/main/java/de/juplo/kafka/wordcount/top10/Top10StreamProcessor.java
index 2ff078c..343ab4d 100644
--- a/src/main/java/de/juplo/kafka/wordcount/top10/Top10StreamProcessor.java
+++ b/src/main/java/de/juplo/kafka/wordcount/top10/Top10StreamProcessor.java
@@ -1,11 +1,10 @@
 package de.juplo.kafka.wordcount.top10;
 
 import lombok.extern.slf4j.Slf4j;
-import org.apache.kafka.streams.KafkaStreams;
-import org.apache.kafka.streams.KeyValue;
-import org.apache.kafka.streams.StreamsBuilder;
-import org.apache.kafka.streams.Topology;
+import org.apache.kafka.streams.*;
+import org.apache.kafka.streams.kstream.Materialized;
 import org.apache.kafka.streams.state.KeyValueBytesStoreSupplier;
+import org.apache.kafka.streams.state.QueryableStoreTypes;
 import org.apache.kafka.streams.state.ReadOnlyKeyValueStore;
 
 import java.util.Properties;
@@ -20,12 +19,13 @@ public class Top10StreamProcessor
 	public Top10StreamProcessor(
 			String inputTopic,
 			String outputTopic,
-			Properties props)
+			Properties props,
+			KeyValueBytesStoreSupplier storeSupplier)
 	{
 		Topology topology = Top10StreamProcessor.buildTopology(
 				inputTopic,
 				outputTopic,
-				null);
+				storeSupplier);
 
 		streams = new KafkaStreams(topology, props);
 	}
@@ -43,7 +43,8 @@ public class Top10StreamProcessor
 				.groupByKey()
 				.aggregate(
 						() -> new Ranking(),
-						(user, entry, ranking) -> ranking.add(entry))
+						(user, entry, ranking) -> ranking.add(entry),
+						Materialized.as(storeSupplier))
 				.toStream()
 				.to(outputTopic);
 
@@ -55,7 +56,7 @@ public class Top10StreamProcessor
 
 	ReadOnlyKeyValueStore<User, Ranking> getStore(String name)
 	{
-		return null;
+		return streams.store(StoreQueryParameters.fromNameAndType(name, QueryableStoreTypes.keyValueStore()));
 	}
 
 	public void start()
diff --git a/src/test/java/de/juplo/kafka/wordcount/top10/Top10ApplicationIT.java b/src/test/java/de/juplo/kafka/wordcount/top10/Top10ApplicationIT.java
index 726b1e7..d55048d 100644
--- a/src/test/java/de/juplo/kafka/wordcount/top10/Top10ApplicationIT.java
+++ b/src/test/java/de/juplo/kafka/wordcount/top10/Top10ApplicationIT.java
@@ -6,9 +6,7 @@ import de.juplo.kafka.wordcount.query.TestRanking;
 import lombok.extern.slf4j.Slf4j;
 import org.apache.kafka.streams.state.KeyValueBytesStoreSupplier;
 import org.apache.kafka.streams.state.Stores;
-import org.junit.jupiter.api.BeforeAll;
-import org.junit.jupiter.api.DisplayName;
-import org.junit.jupiter.api.Test;
+import org.junit.jupiter.api.*;
 import org.springframework.beans.factory.annotation.Autowired;
 import org.springframework.boot.test.context.SpringBootTest;
 import org.springframework.boot.test.context.TestConfiguration;
@@ -101,6 +99,7 @@ public class Top10ApplicationIT
 
 	@DisplayName("Await the expected output messages")
 	@Test
+	@Disabled
 	public void testAwaitExpectedMessages()
 	{
 		await("Expected messages")