1 package de.juplo.kafka.wordcount.splitter;
3 import lombok.extern.slf4j.Slf4j;
4 import org.apache.kafka.clients.consumer.ConsumerConfig;
5 import org.apache.kafka.common.serialization.Serdes;
6 import org.apache.kafka.streams.KafkaStreams;
7 import org.apache.kafka.streams.StreamsBuilder;
8 import org.apache.kafka.streams.StreamsConfig;
9 import org.apache.kafka.streams.kstream.KStream;
10 import org.springframework.boot.SpringApplication;
11 import org.springframework.context.ConfigurableApplicationContext;
12 import org.springframework.kafka.support.serializer.JsonDeserializer;
13 import org.springframework.kafka.support.serializer.JsonSerde;
14 import org.springframework.kafka.support.serializer.JsonSerializer;
15 import org.springframework.stereotype.Component;
17 import jakarta.annotation.PostConstruct;
18 import jakarta.annotation.PreDestroy;
19 import java.util.Arrays;
20 import java.util.Properties;
21 import java.util.concurrent.CompletableFuture;
22 import java.util.regex.Pattern;
24 import static org.apache.kafka.streams.errors.StreamsUncaughtExceptionHandler.StreamThreadExceptionResponse.SHUTDOWN_CLIENT;
29 public class SplitterStreamProcessor
31 final static Pattern PATTERN = Pattern.compile("\\W+");
33 public final KafkaStreams streams;
36 public SplitterStreamProcessor(
37 SplitterApplicationProperties properties,
38 ConfigurableApplicationContext context)
40 StreamsBuilder builder = new StreamsBuilder();
42 KStream<String, Recording> source = builder.stream(properties.getInputTopic());
45 .flatMapValues(recording -> Arrays
46 .stream(PATTERN.split(recording.getSentence()))
47 .map(word -> Word.of(recording.getUser(), word))
49 .to(properties.getOutputTopic());
51 Properties props = new Properties();
52 props.put(StreamsConfig.APPLICATION_ID_CONFIG, properties.getApplicationId());
53 props.put(StreamsConfig.BOOTSTRAP_SERVERS_CONFIG, properties.getBootstrapServer());
54 props.put(StreamsConfig.DEFAULT_KEY_SERDE_CLASS_CONFIG, Serdes.StringSerde.class.getName());
55 props.put(StreamsConfig.DEFAULT_VALUE_SERDE_CLASS_CONFIG, JsonSerde.class.getName());
56 props.put(JsonDeserializer.TRUSTED_PACKAGES, Recording.class.getName() );
57 props.put(JsonDeserializer.VALUE_DEFAULT_TYPE, Recording.class.getName());
58 props.put(JsonSerializer.ADD_TYPE_INFO_HEADERS, false);
59 props.put(ConsumerConfig.AUTO_OFFSET_RESET_CONFIG, "earliest");
61 streams = new KafkaStreams(builder.build(), props);
62 streams.setUncaughtExceptionHandler((Throwable e) ->
64 log.error("Unexpected error!", e);
65 CompletableFuture.runAsync(() ->
67 log.info("Stopping application...");
68 SpringApplication.exit(context, () -> 1);
70 return SHUTDOWN_CLIENT;
77 log.info("Starting Stream-Processor");
84 log.info("Stopping Stream-Processor");