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.stereotype.Component;
14 import javax.annotation.PostConstruct;
15 import javax.annotation.PreDestroy;
16 import java.util.Arrays;
17 import java.util.Properties;
18 import java.util.concurrent.CompletableFuture;
19 import java.util.regex.Pattern;
21 import static org.apache.kafka.streams.errors.StreamsUncaughtExceptionHandler.StreamThreadExceptionResponse.SHUTDOWN_CLIENT;
26 public class SplitterStreamProcessor
28 final static Pattern PATTERN = Pattern.compile("\\W+");
30 public final KafkaStreams streams;
33 public SplitterStreamProcessor(
34 SplitterApplicationProperties properties,
35 ConfigurableApplicationContext context)
37 StreamsBuilder builder = new StreamsBuilder();
39 KStream<String, String> source = builder.stream(properties.getInputTopic());
41 .flatMapValues(sentence -> Arrays.asList(PATTERN.split(sentence)))
42 .to(properties.getOutputTopic());
44 Properties props = new Properties();
45 props.put(StreamsConfig.APPLICATION_ID_CONFIG, properties.getApplicationId());
46 props.put(StreamsConfig.BOOTSTRAP_SERVERS_CONFIG, properties.getBootstrapServer());
47 props.put(StreamsConfig.DEFAULT_KEY_SERDE_CLASS_CONFIG, Serdes.String().getClass().getName());
48 props.put(StreamsConfig.DEFAULT_VALUE_SERDE_CLASS_CONFIG, Serdes.String().getClass().getName());
49 props.put(ConsumerConfig.AUTO_OFFSET_RESET_CONFIG, "earliest");
51 streams = new KafkaStreams(builder.build(), props);
52 streams.setUncaughtExceptionHandler((Throwable e) ->
54 log.error("Unexpected error!", e);
55 CompletableFuture.runAsync(() ->
57 log.info("Stopping application...");
58 SpringApplication.exit(context, () -> 1);
60 return SHUTDOWN_CLIENT;
67 log.info("Starting Stream-Processor");
74 log.info("Stopping Stream-Processor");