import org.apache.kafka.streams.StreamsBuilder;
import org.apache.kafka.streams.Topology;
import org.apache.kafka.streams.kstream.KStream;
-import org.apache.kafka.streams.kstream.Materialized;
import org.apache.kafka.streams.state.KeyValueBytesStoreSupplier;
import org.apache.kafka.streams.kstream.*;
-import org.springframework.kafka.support.serializer.JsonSerde;
import java.util.Properties;
KStream<String, Word> source = builder.stream(
inputTopic,
- Consumed.with(
- Serdes.String(),
- new JsonSerde<>(Word.class)
- .ignoreTypeHeaders()));
+ Consumed.with(Serdes.String(), null));
source
.map((key, word) -> new KeyValue<>(word, word))
- .groupByKey(Grouped.with(
- new JsonSerde<>(Word.class)
- .forKeys()
- .noTypeInfo(),
- new JsonSerde<>(Word.class)
- .noTypeInfo()))
+ .groupByKey()
.count(Materialized.as(storeSupplier))
.toStream()
- .map((word, count) -> new KeyValue<>(word, WordCount.of(word.getUser(), word.getWord(), count)))
- .to(
- outputTopic,
- Produced.with(
- new JsonSerde<>(Word.class)
- .forKeys()
- .noTypeInfo(),
- new JsonSerde<>(WordCount.class)
- .noTypeInfo()));
+ .map((word, count) -> new KeyValue<>(word, WordCount.of(word, count)))
+ .to(outputTopic);
Topology topology = builder.build();
log.info("\n\n{}", topology.describe());