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;
@Slf4j
public class Top10StreamProcessor
{
+ public static final String STORE_NAME= "top10";
+
public final KafkaStreams streams;
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);
}
.groupByKey()
.aggregate(
() -> new Ranking(),
- (user, entry, ranking) -> ranking.add(entry))
+ (user, entry, ranking) -> ranking.add(entry),
+ Materialized.as(storeSupplier))
.toStream()
.to(outputTopic);
return topology;
}
- ReadOnlyKeyValueStore<User, Ranking> getStore(String name)
+ ReadOnlyKeyValueStore<User, Ranking> getStore()
{
- return null;
+ return streams.store(StoreQueryParameters.fromNameAndType(STORE_NAME, QueryableStoreTypes.keyValueStore()));
}
public void start()