package de.juplo.kafka.wordcount.top10;
-import com.fasterxml.jackson.core.JsonProcessingException;
-import com.fasterxml.jackson.databind.ObjectMapper;
-import jakarta.annotation.PostConstruct;
-import jakarta.annotation.PreDestroy;
import lombok.extern.slf4j.Slf4j;
import org.apache.kafka.clients.consumer.ConsumerConfig;
-import org.apache.kafka.common.serialization.Serdes;
-import org.apache.kafka.streams.KafkaStreams;
-import org.apache.kafka.streams.KeyValue;
-import org.apache.kafka.streams.StreamsBuilder;
import org.apache.kafka.streams.StreamsConfig;
+import org.apache.kafka.streams.state.KeyValueBytesStoreSupplier;
+import org.apache.kafka.streams.state.Stores;
import org.springframework.boot.SpringApplication;
+import org.springframework.boot.context.properties.EnableConfigurationProperties;
import org.springframework.context.ConfigurableApplicationContext;
-import org.springframework.stereotype.Component;
+import org.springframework.context.annotation.Bean;
+import org.springframework.context.annotation.Configuration;
+import org.springframework.kafka.support.serializer.JsonDeserializer;
+import org.springframework.kafka.support.serializer.JsonSerde;
+import org.springframework.kafka.support.serializer.JsonSerializer;
import java.util.Properties;
import java.util.concurrent.CompletableFuture;
-import java.util.regex.Pattern;
import static org.apache.kafka.streams.errors.StreamsUncaughtExceptionHandler.StreamThreadExceptionResponse.SHUTDOWN_CLIENT;
+@Configuration
+@EnableConfigurationProperties(Top10ApplicationProperties.class)
@Slf4j
-@Component
public class Top10ApplicationConfiguration
{
- final static Pattern PATTERN = Pattern.compile("\\W+");
-
- public final KafkaStreams streams;
-
-
- public Top10ApplicationConfiguration(
- Top10ApplicationProperties properties,
- ObjectMapper mapper,
- ConfigurableApplicationContext context)
+ @Bean
+ public Properties streamProcessorProperties(Top10ApplicationProperties properties)
{
- StreamsBuilder builder = new StreamsBuilder();
-
- builder
- .<String, String>stream(properties.getInputTopic())
- .map((keyJson, countStr) ->
- {
- try
- {
- Key key = mapper.readValue(keyJson, Key.class);
- Long count = Long.parseLong(countStr);
- Entry entry = Entry.of(key.getWord(), count);
- String entryJson = mapper.writeValueAsString(entry);
- return new KeyValue<>(key.getUsername(), entryJson);
- }
- catch (JsonProcessingException e)
- {
- throw new RuntimeException(e);
- }
- })
- .groupByKey()
- .aggregate(
- () -> "{\"entries\" : []}",
- (username, entryJson, rankingJson) ->
- {
- try
- {
- Ranking ranking = mapper.readValue(rankingJson, Ranking.class);
- ranking.add(mapper.readValue(entryJson, Entry.class));
- return mapper.writeValueAsString(ranking);
- }
- catch (JsonProcessingException e)
- {
- throw new RuntimeException(e);
- }
- }
- )
- .toStream()
- .to(properties.getOutputTopic());
-
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_KEY_SERDE_CLASS_CONFIG, JsonSerde.class.getName());
+ props.put(StreamsConfig.DEFAULT_VALUE_SERDE_CLASS_CONFIG, JsonSerde.class.getName());
+ props.put(JsonDeserializer.TRUSTED_PACKAGES, Top10Application.class.getPackageName());
+ props.put(JsonDeserializer.KEY_DEFAULT_TYPE, User.class.getName());
+ props.put(JsonDeserializer.VALUE_DEFAULT_TYPE, Ranking.class.getName());
+ props.put(
+ JsonDeserializer.TYPE_MAPPINGS,
+ "word:" + Key.class.getName() + "," +
+ "counter:" + Entry.class.getName() + "," +
+ "user:" + User.class.getName() + "," +
+ "ranking:" + Ranking.class.getName());
+ props.put(ConsumerConfig.AUTO_OFFSET_RESET_CONFIG, "earliest");
+ if (properties.getCommitInterval() != null)
+ props.put(StreamsConfig.COMMIT_INTERVAL_MS_CONFIG, properties.getCommitInterval());
+ if (properties.getCacheMaxBytes() != null)
+ props.put(StreamsConfig.STATESTORE_CACHE_MAX_BYTES_CONFIG, properties.getCacheMaxBytes());
props.put(ConsumerConfig.AUTO_OFFSET_RESET_CONFIG, "earliest");
- streams = new KafkaStreams(builder.build(), props);
- streams.setUncaughtExceptionHandler((Throwable e) ->
+ return props;
+ }
+
+ @Bean(initMethod = "start", destroyMethod = "stop")
+ public Top10StreamProcessor streamProcessor(
+ Top10ApplicationProperties applicationProperties,
+ Properties streamProcessorProperties,
+ KeyValueBytesStoreSupplier storeSupplier,
+ ConfigurableApplicationContext context)
+ {
+ Top10StreamProcessor streamProcessor = new Top10StreamProcessor(
+ applicationProperties.getInputTopic(),
+ applicationProperties.getOutputTopic(),
+ streamProcessorProperties,
+ storeSupplier);
+
+ streamProcessor.streams.setUncaughtExceptionHandler((Throwable e) ->
{
log.error("Unexpected error!", e);
CompletableFuture.runAsync(() ->
});
return SHUTDOWN_CLIENT;
});
- }
- @PostConstruct
- public void start()
- {
- log.info("Starting Stream-Processor");
- streams.start();
+ return streamProcessor;
}
- @PreDestroy
- public void stop()
+ @Bean
+ public KeyValueBytesStoreSupplier storeSupplier()
{
- log.info("Stopping Stream-Processor");
- streams.close();
+ return Stores.persistentKeyValueStore("top10");
}
}