counter: 1.3.1 - Refined/Simplified the type-mapping

[demos/kafka/wordcount] / src / main / java / de / juplo / kafka / wordcount / counter / CounterStreamProcessor.java

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 8b9c12b..97d460f 100644 (file)
--- a/src/main/java/de/juplo/kafka/wordcount/counter/CounterStreamProcessor.java
+++ b/src/main/java/de/juplo/kafka/wordcount/counter/CounterStreamProcessor.java
@@ -4,12 +4,16 @@ import lombok.extern.slf4j.Slf4j;
 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
@@ -56,7 +60,7 @@ public class CounterStreamProcessor
                                                                .withKeySerde(new JsonSerde<>().copyWithType(Word.class).forKeys()))
                                .toStream()
                                .map((word, counter) -> new KeyValue<>(word, WordCounter.of(word, counter)))
-                               .to(outputTopic);
+                               .to(outputTopic, Produced.with(outKeySerde(), outValueSerde()));
 
                Topology topology = builder.build();
                log.info("\n\n{}", topology.describe());
@@ -80,4 +84,41 @@ public class CounterStreamProcessor
                log.info("Stopping Stream-Processor");
                streams.close();
        }
+
+
+
+       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 typeMappings()
+                               .entrySet()
+                               .stream()
+                               .map(entry -> entry.getKey() + ":" + entry.getValue().getName())
+                               .collect(Collectors.joining(","));
+       }
+
+       private static Map<String, Class> typeMappings()
+       {
+               return Map.of(
+                               "word", Word.class,
+                               "counter", WordCounter.class);
+       }
 }