X-Git-Url: https://juplo.de/gitweb/?a=blobdiff_plain;f=src%2Fmain%2Fjava%2Fde%2Fjuplo%2Fkafka%2Fwordcount%2Fcounter%2FCounterStreamProcessor.java;h=455d89561ddb0fddddf4b68e51d724e6e4d06453;hb=refs%2Fheads%2Fcounter;hp=4002df2d9872978f7feddc2110cd6df07b402888;hpb=b02b75a4e70c41795a58ca38cd62d455af8aea16;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 4002df2..455d895 100644
--- a/src/main/java/de/juplo/kafka/wordcount/counter/CounterStreamProcessor.java
+++ b/src/main/java/de/juplo/kafka/wordcount/counter/CounterStreamProcessor.java
@@ -1,22 +1,28 @@
 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.streams.KafkaStreams;
-import org.apache.kafka.streams.KeyValue;
-import org.apache.kafka.streams.StreamsBuilder;
-import org.apache.kafka.streams.Topology;
-import org.apache.kafka.streams.kstream.KStream;
+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 java.util.Map;
 import java.util.Properties;
+import java.util.stream.Collectors;
 
 
 @Slf4j
 public class CounterStreamProcessor
 {
+	public static final String TYPE = "COUNTER";
+	public static final String STORE_NAME = "counter";
+
+
 	public final KafkaStreams streams;
 
 
@@ -24,14 +30,12 @@ public class CounterStreamProcessor
 			String inputTopic,
 			String outputTopic,
 			Properties properties,
-			KeyValueBytesStoreSupplier storeSupplier,
-			ObjectMapper mapper)
+			KeyValueBytesStoreSupplier storeSupplier)
 	{
 		Topology topology = CounterStreamProcessor.buildTopology(
 				inputTopic,
 				outputTopic,
-				storeSupplier,
-				mapper);
+				storeSupplier);
 
 		streams = new KafkaStreams(topology, properties);
 	}
@@ -39,32 +43,32 @@ public class CounterStreamProcessor
 	static Topology buildTopology(
 			String inputTopic,
 			String outputTopic,
-			KeyValueBytesStoreSupplier storeSupplier,
-			ObjectMapper mapper)
+			KeyValueBytesStoreSupplier storeSupplier)
 	{
 		StreamsBuilder builder = new StreamsBuilder();
 
-		KStream<String, String> source = builder.stream(inputTopic);
-		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(Materialized.as(storeSupplier))
-				.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(outputTopic);
+				.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;
+	}
 
-		return builder.build();
+	ReadOnlyKeyValueStore<Word, Long> getStore()
+	{
+		return streams.store(StoreQueryParameters.fromNameAndType(STORE_NAME, QueryableStoreTypes.keyValueStore()));
 	}
 
 	public void start()
@@ -78,4 +82,51 @@ public class CounterStreamProcessor
 		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(","));
+	}
 }