X-Git-Url: https://juplo.de/gitweb/?a=blobdiff_plain;f=src%2Fmain%2Fjava%2Fde%2Fjuplo%2Fkafka%2Fwordcount%2Fcounter%2FCounterStreamProcessor.java;h=2304e558c242359f9303d6c2fdbfe33b4b419120;hb=refs%2Fheads%2Fcounter;hp=524860977e15dfed0a1b9a8af0061f08b4ff851b;hpb=aec12e4b0a06b6a8f32c789dd75be45c6e71f343;p=demos%2Fkafka%2Fwordcount

diff --git a/src/main/java/de/juplo/kafka/wordcount/counter/CounterStreamProcessor.java b/src/main/java/de/juplo/kafka/wordcount/counter/CounterStreamProcessor.java
index 5248609..455d895 100644
--- a/src/main/java/de/juplo/kafka/wordcount/counter/CounterStreamProcessor.java
+++ b/src/main/java/de/juplo/kafka/wordcount/counter/CounterStreamProcessor.java
@@ -1,92 +1,132 @@
 package de.juplo.kafka.wordcount.counter;
 
-import com.fasterxml.jackson.core.JsonProcessingException;
-import com.fasterxml.jackson.databind.ObjectMapper;
 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.kstream.KStream;
-import org.springframework.boot.SpringApplication;
-import org.springframework.context.ConfigurableApplicationContext;
-import org.springframework.stereotype.Component;
-
-import jakarta.annotation.PostConstruct;
-import jakarta.annotation.PreDestroy;
-import java.util.Properties;
-import java.util.concurrent.CompletableFuture;
+import org.apache.kafka.streams.*;
+import org.apache.kafka.streams.kstream.Consumed;
+import org.apache.kafka.streams.kstream.Materialized;
+import org.apache.kafka.streams.kstream.Produced;
+import org.apache.kafka.streams.state.KeyValueBytesStoreSupplier;
+import org.apache.kafka.streams.state.QueryableStoreTypes;
+import org.apache.kafka.streams.state.ReadOnlyKeyValueStore;
+import org.springframework.kafka.support.serializer.JsonSerde;
+import org.springframework.kafka.support.serializer.JsonSerializer;
 
-import static org.apache.kafka.streams.errors.StreamsUncaughtExceptionHandler.StreamThreadExceptionResponse.SHUTDOWN_CLIENT;
+import java.util.Map;
+import java.util.Properties;
+import java.util.stream.Collectors;
 
 
 @Slf4j
-@Component
 public class CounterStreamProcessor
 {
+	public static final String TYPE = "COUNTER";
+	public static final String STORE_NAME = "counter";
+
+
 	public final KafkaStreams streams;
 
 
 	public CounterStreamProcessor(
-			CounterApplicationProperties properties,
-			ObjectMapper mapper,
-			ConfigurableApplicationContext context)
+			String inputTopic,
+			String outputTopic,
+			Properties properties,
+			KeyValueBytesStoreSupplier storeSupplier)
+	{
+		Topology topology = CounterStreamProcessor.buildTopology(
+				inputTopic,
+				outputTopic,
+				storeSupplier);
+
+		streams = new KafkaStreams(topology, properties);
+	}
+
+	static Topology buildTopology(
+			String inputTopic,
+			String outputTopic,
+			KeyValueBytesStoreSupplier storeSupplier)
 	{
 		StreamsBuilder builder = new StreamsBuilder();
 
-		KStream<String, String> source = builder.stream(properties.getInputTopic());
-		source
-				.map((username, word) ->
-				{
-					try
-					{
-						String key = mapper.writeValueAsString(Key.of(username, word));
-						return new KeyValue<>(key, word);
-					}
-					catch (JsonProcessingException e)
-					{
-						throw new RuntimeException(e);
-					}
-				})
+		builder
+				.stream(inputTopic, Consumed.with(inKeySerde(), inValueSerde()))
+				.mapValues(word -> Word.of(word.getUser(), word.getWord()))
+				.map((key, word) -> new KeyValue<>(word, word))
 				.groupByKey()
-				.count()
-				.mapValues(value->Long.toString(value))
+				.count(
+						Materialized
+								.<Word, Long>as(storeSupplier)
+								.withKeySerde(new JsonSerde<>(Word.class))) // No headers are present: fixed typing is needed!
 				.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(ConsumerConfig.AUTO_OFFSET_RESET_CONFIG, "earliest");
-
-		streams = new KafkaStreams(builder.build(), props);
-		streams.setUncaughtExceptionHandler((Throwable e) ->
-		{
-			log.error("Unexpected error!", e);
-			CompletableFuture.runAsync(() ->
-			{
-				log.info("Stopping application...");
-				SpringApplication.exit(context, () -> 1);
-			});
-			return SHUTDOWN_CLIENT;
-		});
+				.map((word, counter) -> new KeyValue<>(word, WordCounter.of(word, counter)))
+				.to(outputTopic, Produced.with(outKeySerde(), outValueSerde()));
+
+		Topology topology = builder.build();
+		log.info("\n\n{}", topology.describe());
+
+		return topology;
+	}
+
+	ReadOnlyKeyValueStore<Word, Long> getStore()
+	{
+		return streams.store(StoreQueryParameters.fromNameAndType(STORE_NAME, QueryableStoreTypes.keyValueStore()));
 	}
 
-	@PostConstruct
 	public void start()
 	{
 		log.info("Starting Stream-Processor");
 		streams.start();
 	}
 
-	@PreDestroy
 	public void stop()
 	{
 		log.info("Stopping Stream-Processor");
 		streams.close();
 	}
+
+
+
+	public static JsonSerde<User> inKeySerde()
+	{
+		return new JsonSerde<>(User.class);
+	}
+
+	public static JsonSerde<UserWord> inValueSerde()
+	{
+		return new JsonSerde<>(UserWord.class);
+	}
+
+	public static JsonSerde<Word> outKeySerde()
+	{
+		return serde(true);
+	}
+
+	public static JsonSerde<WordCounter> outValueSerde()
+	{
+		return serde(false);
+	}
+
+	public static <T> JsonSerde<T> serde(boolean isKey)
+	{
+		JsonSerde<T> serde = new JsonSerde<>();
+		serde.configure(
+				Map.of(JsonSerializer.TYPE_MAPPINGS, typeMappingsConfig()),
+				isKey);
+		return serde;
+	}
+
+	private static String typeMappingsConfig()
+	{
+		return typeMappingsConfig(Word.class, WordCounter.class);
+	}
+
+	public static String typeMappingsConfig(Class keyClass, Class counterClass)
+	{
+		return Map.of(
+						"key", keyClass,
+						"counter", counterClass)
+				.entrySet()
+				.stream()
+				.map(entry -> entry.getKey() + ":" + entry.getValue().getName())
+				.collect(Collectors.joining(","));
+	}
 }