From: Kai Moritz <kai@juplo.de>
Date: Thu, 14 Oct 2021 17:38:19 +0000 (+0200)
Subject: WIP
X-Git-Url: https://juplo.de/gitweb/?p=demos%2Fkafka%2Fwordcount;a=commitdiff_plain;h=37e0703a25b489b0258f6ef019c57e82863394e4

WIP
---

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 aa21c4a..811cf98 100644
--- a/src/main/java/de/juplo/kafka/wordcount/top10/Top10StreamProcessor.java
+++ b/src/main/java/de/juplo/kafka/wordcount/top10/Top10StreamProcessor.java
@@ -10,11 +10,9 @@ import io.confluent.kafka.streams.serdes.avro.SpecificAvroSerializer;
 import lombok.extern.slf4j.Slf4j;
 import org.apache.kafka.clients.consumer.ConsumerConfig;
 import org.apache.kafka.common.serialization.Serdes;
-import org.apache.kafka.streams.KafkaStreams;
-import org.apache.kafka.streams.KeyValue;
-import org.apache.kafka.streams.StreamsBuilder;
-import org.apache.kafka.streams.StreamsConfig;
+import org.apache.kafka.streams.*;
 import org.apache.kafka.streams.kstream.Consumed;
+import org.apache.kafka.streams.kstream.Grouped;
 import org.apache.kafka.streams.kstream.Materialized;
 import org.apache.kafka.streams.kstream.Produced;
 import org.springframework.boot.SpringApplication;
@@ -23,6 +21,7 @@ import org.springframework.stereotype.Component;
 
 import javax.annotation.PostConstruct;
 import javax.annotation.PreDestroy;
+import java.util.LinkedList;
 import java.util.Properties;
 import java.util.concurrent.CompletableFuture;
 import java.util.regex.Pattern;
@@ -51,14 +50,13 @@ public class Top10StreamProcessor
 				.map((key, count) -> new KeyValue<>(
 						key.getUsername(),
 						Entry.newBuilder().setWord(key.getWord()).setCount(count).build()))
-				.groupByKey()
+				.groupByKey(Grouped.keySerde(Serdes.String()))
 				.aggregate(
-						() -> Ranking.newBuilder().build(),
+						() -> Ranking.newBuilder().setEntries(new LinkedList<Entry>()).build(),
 						(username, entry, ranking) -> {
 							ranking.getEntries().add(entry);
 							return ranking;
-						},
-						Materialized.with(Serdes.String(), null))
+						})
 				.toStream()
 				.to(properties.getOutputTopic(), Produced.keySerde(Serdes.String()));
 
@@ -70,7 +68,10 @@ public class Top10StreamProcessor
 		props.put(AbstractKafkaSchemaSerDeConfig.SCHEMA_REGISTRY_URL_CONFIG, properties.getSchemaRegistry());
 		props.put(ConsumerConfig.AUTO_OFFSET_RESET_CONFIG, "earliest");
 
-		streams = new KafkaStreams(builder.build(), props);
+		Topology topology = builder.build();
+		log.info("Topology:\n-----------------\n\n{}-----------------", topology.describe());
+
+		streams = new KafkaStreams(topology, props);
 		streams.setUncaughtExceptionHandler((Throwable e) ->
 		{
 			log.error("Unexpected error!", e);