splitter: 1.1.0 - Input/Output is expected/read as JSON

[demos/kafka/wordcount] / src / main / java / de / juplo / kafka / wordcount / splitter / SplitterStreamProcessor.java

diff --git a/src/main/java/de/juplo/kafka/wordcount/splitter/SplitterStreamProcessor.java b/src/main/java/de/juplo/kafka/wordcount/splitter/SplitterStreamProcessor.java
index 3eca8f4..12816ab 100644 (file)
--- a/src/main/java/de/juplo/kafka/wordcount/splitter/SplitterStreamProcessor.java
+++ b/src/main/java/de/juplo/kafka/wordcount/splitter/SplitterStreamProcessor.java
@@ -6,9 +6,12 @@ import org.apache.kafka.common.serialization.Serdes;
 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;
@@ -36,16 +39,27 @@ public class SplitterStreamProcessor
        {
                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);