top10: 1.2.1 - (GREEN) Made the aggregation state accessible
authorKai Moritz <kai@juplo.de>
Thu, 30 May 2024 09:01:27 +0000 (11:01 +0200)
committerKai Moritz <kai@juplo.de>
Sat, 8 Jun 2024 11:15:05 +0000 (13:15 +0200)
* 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.

src/main/java/de/juplo/kafka/wordcount/top10/Top10ApplicationConfiguration.java
src/main/java/de/juplo/kafka/wordcount/top10/Top10StreamProcessor.java
src/test/java/de/juplo/kafka/wordcount/top10/Top10ApplicationIT.java

index 000db01..6e1f93f 100644 (file)
@@ -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");
+       }
 }
index 2ff078c..343ab4d 100644 (file)
@@ -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()
index 726b1e7..d55048d 100644 (file)
@@ -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")