X-Git-Url: https://juplo.de/gitweb/?a=blobdiff_plain;f=src%2Fmain%2Fjava%2Fde%2Fjuplo%2Fkafka%2Fwordcount%2Ftop10%2FTop10StreamProcessor.java;h=2bc1da7ddd544864909a9fc882b8b84daaeef9d7;hb=42bb92cf8fca73ddf940f2257c7fa5f693bc2ca4;hp=276ca8e7239021880d6a86cec9d27b4367daf7bc;hpb=46d16efa66a06c24aa2286b4dd14676f9168b4e2;p=demos%2Fkafka%2Fwordcount

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 276ca8e..2bc1da7 100644
--- a/src/main/java/de/juplo/kafka/wordcount/top10/Top10StreamProcessor.java
+++ b/src/main/java/de/juplo/kafka/wordcount/top10/Top10StreamProcessor.java
@@ -6,19 +6,24 @@ import de.juplo.kafka.wordcount.avro.Key;
 import de.juplo.kafka.wordcount.avro.Ranking;
 import io.confluent.kafka.serializers.AbstractKafkaSchemaSerDeConfig;
 import io.confluent.kafka.streams.serdes.avro.SpecificAvroSerde;
+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;
 import org.springframework.context.ConfigurableApplicationContext;
 import org.springframework.stereotype.Component;
 
 import javax.annotation.PostConstruct;
 import javax.annotation.PreDestroy;
+import java.util.Arrays;
+import java.util.LinkedList;
+import java.util.List;
 import java.util.Properties;
 import java.util.concurrent.CompletableFuture;
 import java.util.regex.Pattern;
@@ -43,29 +48,63 @@ public class Top10StreamProcessor
 		StreamsBuilder builder = new StreamsBuilder();
 
 		builder
-				.<Key, Long>stream(properties.getInputTopic())
+				.<Key, Long>stream(properties.getInputTopic(), Consumed.with(null, Serdes.Long()))
 				.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(),
-						(username, entry, ranking) -> {
-							ranking.getEntries().add(entry);
+						() -> Ranking.newBuilder().setEntries(new LinkedList<Entry>()).build(),
+						(username, newEntry, ranking) -> {
+							List<Entry> entries = new LinkedList<>(ranking.getEntries());
+
+							if (entries.isEmpty())
+							{
+								entries.add(newEntry);
+							}
+							else
+							{
+								for (int i = 0; i < entries.size(); i++)
+								{
+									Entry entry = entries.get(i);
+									if (entry.getCount() <= newEntry.getCount())
+									{
+										entries.add(i, newEntry);
+										for (int j = i + 1; j < entries.size(); j++)
+										{
+											entry = entries.get(j);
+											if (entry.getWord().equals(newEntry.getWord()))
+											{
+												entries.remove(j);
+												break;
+											}
+										}
+										if (entries.size() > 10)
+										{
+											entries = entries.subList(0, 10);
+										}
+									}
+								}
+							}
+
+							ranking.setEntries(entries);
 							return ranking;
 						})
 				.toStream()
-				.to(properties.getOutputTopic());
+				.to(properties.getOutputTopic(), Produced.keySerde(Serdes.String()));
 
 		Properties props = new Properties();
 		props.put(StreamsConfig.APPLICATION_ID_CONFIG, properties.getApplicationId());
 		props.put(StreamsConfig.BOOTSTRAP_SERVERS_CONFIG, properties.getBootstrapServer());
-		props.put(StreamsConfig.DEFAULT_KEY_SERDE_CLASS_CONFIG, Serdes.String().getClass());
+		props.put(StreamsConfig.DEFAULT_KEY_SERDE_CLASS_CONFIG, SpecificAvroSerde.class);
 		props.put(StreamsConfig.DEFAULT_VALUE_SERDE_CLASS_CONFIG, SpecificAvroSerde.class);
 		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);