From: Kai Moritz <kai@juplo.de>
Date: Sun, 5 Feb 2023 11:18:18 +0000 (+0100)
Subject: splitter: 1.1.2 - De-/Serialization are both using the default-serde
X-Git-Url: https://juplo.de/gitweb/?p=demos%2Fkafka%2Fwordcount;a=commitdiff_plain;h=f132033a6793fc566962a4361d7d0a0e852b0f82

splitter: 1.1.2 - De-/Serialization are both using the default-serde

- Configured the default-serde for the expeced input and the intended output
- The configuration has to be supplied explicitly in the `Properties`,
  that are handed over during the instanciation of `KafkaStreams`.
- The `JsonDeserializer` needs the definition of a default-type for the
  value and position of trust for the class, that should be instanciated.
- The `JsonSerializer` should be advised to _not_ add the header
  `__TypeId__`, because it is not needed, if the topic only contains
  messages of a single type.
---

diff --git a/src/main/java/de/juplo/kafka/wordcount/splitter/SplitterStreamProcessor.java b/src/main/java/de/juplo/kafka/wordcount/splitter/SplitterStreamProcessor.java
index 5e4930d..86d5bbd 100644
--- a/src/main/java/de/juplo/kafka/wordcount/splitter/SplitterStreamProcessor.java
+++ b/src/main/java/de/juplo/kafka/wordcount/splitter/SplitterStreamProcessor.java
@@ -6,12 +6,12 @@ import org.apache.kafka.common.serialization.Serdes;
 import org.apache.kafka.streams.KafkaStreams;
 import org.apache.kafka.streams.StreamsBuilder;
 import org.apache.kafka.streams.StreamsConfig;
-import org.apache.kafka.streams.kstream.Consumed;
 import org.apache.kafka.streams.kstream.KStream;
-import org.apache.kafka.streams.kstream.Produced;
 import org.springframework.boot.SpringApplication;
 import org.springframework.context.ConfigurableApplicationContext;
+import org.springframework.kafka.support.serializer.JsonDeserializer;
 import org.springframework.kafka.support.serializer.JsonSerde;
+import org.springframework.kafka.support.serializer.JsonSerializer;
 import org.springframework.stereotype.Component;
 
 import jakarta.annotation.PostConstruct;
@@ -39,12 +39,7 @@ public class SplitterStreamProcessor
 	{
 		StreamsBuilder builder = new StreamsBuilder();
 
-		JsonSerde<Recording> recordSerde =
-				new JsonSerde<>(Recording.class).ignoreTypeHeaders();
-
-		KStream<String, Recording> source = builder.stream(
-				properties.getInputTopic(),
-				Consumed.with(Serdes.String(), recordSerde));
+		KStream<String, Recording> source = builder.stream(properties.getInputTopic());
 
 		source
 				.flatMapValues(recording -> Arrays
@@ -56,8 +51,11 @@ public class SplitterStreamProcessor
 		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_KEY_SERDE_CLASS_CONFIG, Serdes.StringSerde.class.getName());
 		props.put(StreamsConfig.DEFAULT_VALUE_SERDE_CLASS_CONFIG, JsonSerde.class.getName());
+		props.put(JsonDeserializer.TRUSTED_PACKAGES, Recording.class.getName()	);
+		props.put(JsonDeserializer.VALUE_DEFAULT_TYPE, Recording.class.getName());
+		props.put(JsonSerializer.ADD_TYPE_INFO_HEADERS, false);
 		props.put(ConsumerConfig.AUTO_OFFSET_RESET_CONFIG, "earliest");
 
 		streams = new KafkaStreams(builder.build(), props);