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;
public Top10StreamProcessor(
String inputTopic,
String outputTopic,
- Properties props)
+ Properties props,
+ KeyValueBytesStoreSupplier storeSupplier)
{
Topology topology = Top10StreamProcessor.buildTopology(
inputTopic,
- outputTopic);
+ outputTopic,
+ storeSupplier);
streams = new KafkaStreams(topology, props);
}
static Topology buildTopology(
String inputTopic,
- String outputTopic)
+ String outputTopic,
+ KeyValueBytesStoreSupplier storeSupplier)
{
StreamsBuilder builder = new StreamsBuilder();
.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)
+ {
+ return streams.store(StoreQueryParameters.fromNameAndType(name, QueryableStoreTypes.keyValueStore()));
+ }
+
public void start()
{
log.info("Starting Stream-Processor");