import org.apache.kafka.streams.KafkaStreams;
import org.apache.kafka.streams.StreamsBuilder;
import org.apache.kafka.streams.StreamsConfig;
+import org.apache.kafka.streams.kstream.Consumed;
import org.apache.kafka.streams.kstream.KStream;
+import org.apache.kafka.streams.kstream.Produced;
import org.springframework.boot.SpringApplication;
import org.springframework.context.ConfigurableApplicationContext;
+import org.springframework.kafka.support.serializer.JsonSerde;
import org.springframework.stereotype.Component;
import jakarta.annotation.PostConstruct;
{
StreamsBuilder builder = new StreamsBuilder();
- KStream<String, String> source = builder.stream(properties.getInputTopic());
+ JsonSerde<Recording> recordSerde =
+ new JsonSerde<>(Recording.class).ignoreTypeHeaders();
+ JsonSerde<Word> wordSerde =
+ new JsonSerde<>(Word.class).noTypeInfo();
+
+ KStream<String, Recording> source = builder.stream(
+ properties.getInputTopic(),
+ Consumed.with(Serdes.String(), recordSerde));
+
source
- .flatMapValues(sentence -> Arrays.asList(PATTERN.split(sentence)))
- .to(properties.getOutputTopic());
+ .flatMapValues(recording -> Arrays
+ .stream(PATTERN.split(recording.getSentence()))
+ .map(word -> Word.of(recording.getUser(), word))
+ .toList())
+ .to(properties.getOutputTopic(), Produced.with(Serdes.String(), wordSerde));
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().getName());
- props.put(StreamsConfig.DEFAULT_VALUE_SERDE_CLASS_CONFIG, Serdes.String().getClass().getName());
+ props.put(StreamsConfig.DEFAULT_VALUE_SERDE_CLASS_CONFIG, JsonSerde.class.getName());
props.put(ConsumerConfig.AUTO_OFFSET_RESET_CONFIG, "earliest");
streams = new KafkaStreams(builder.build(), props);