query: 2.0.0 - (GREEN) Values are serialized as JSON

[demos/kafka/wordcount] / src / main / java / de / juplo / kafka / wordcount / query / QueryStreamProcessor.java

diff --git a/src/main/java/de/juplo/kafka/wordcount/query/QueryStreamProcessor.java b/src/main/java/de/juplo/kafka/wordcount/query/QueryStreamProcessor.java
index ff7c150..cc65fce 100644 (file)
--- a/src/main/java/de/juplo/kafka/wordcount/query/QueryStreamProcessor.java
+++ b/src/main/java/de/juplo/kafka/wordcount/query/QueryStreamProcessor.java
@@ -1,12 +1,11 @@
 package de.juplo.kafka.wordcount.query;
 
-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.common.serialization.Serdes;
 import org.apache.kafka.streams.*;
+import org.apache.kafka.streams.kstream.Consumed;
 import org.apache.kafka.streams.kstream.KStream;
 import org.apache.kafka.streams.kstream.KTable;
 import org.apache.kafka.streams.kstream.Materialized;
@@ -14,6 +13,7 @@ import org.apache.kafka.streams.state.HostInfo;
 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 java.net.URI;
 import java.util.Optional;
@@ -27,8 +27,7 @@ public class QueryStreamProcessor
 
        public final KafkaStreams streams;
        public final HostInfo hostInfo;
-       public final StoreQueryParameters<ReadOnlyKeyValueStore<String, String>> storeParameters;
-       public final ObjectMapper mapper;
+       public final StoreQueryParameters<ReadOnlyKeyValueStore<String, UserRanking>> storeParameters;
 
 
        public QueryStreamProcessor(
@@ -36,51 +35,36 @@ public class QueryStreamProcessor
                        HostInfo applicationServer,
                        String usersInputTopic,
                        String rankingInputTopic,
-                       KeyValueBytesStoreSupplier storeSupplier,
-                       ObjectMapper mapper)
+                       KeyValueBytesStoreSupplier storeSupplier)
        {
                Topology topology = buildTopology(
                                usersInputTopic,
                                rankingInputTopic,
-                               storeSupplier,
-                               mapper);
+                               storeSupplier);
                streams = new KafkaStreams(topology, props);
                hostInfo = applicationServer;
                storeParameters = StoreQueryParameters.fromNameAndType(STORE_NAME, QueryableStoreTypes.keyValueStore());;
-               this.mapper = mapper;
        }
 
        static Topology buildTopology(
                        String usersInputTopic,
                        String rankingInputTopic,
-                       KeyValueBytesStoreSupplier storeSupplier,
-                       ObjectMapper mapper)
+                       KeyValueBytesStoreSupplier storeSupplier)
        {
                StreamsBuilder builder = new StreamsBuilder();
 
-               KTable<String, String> users = builder.table(usersInputTopic);
-               KStream<String, String> rankings = builder.stream(rankingInputTopic);
+               KTable<String, User> users = builder.table(usersInputTopic);
+               KStream<String, Ranking> rankings = builder.stream(rankingInputTopic);
 
                rankings
-                               .join(users, (rankingJson, userJson) ->
-                               {
-                                       try
-                                       {
-                                               Ranking ranking = mapper.readValue(rankingJson, Ranking.class);
-                                               User user = mapper.readValue(userJson, User.class);
-
-                                               return mapper.writeValueAsString(
-                                                               UserRanking.of(
-                                                                               user.getFirstName(),
-                                                                               user.getLastName(),
-                                                                               ranking.getEntries()));
-                                       }
-                                       catch (JsonProcessingException e)
-                                       {
-                                               throw new RuntimeException(e);
-                                       }
-                               })
-                               .toTable(Materialized.as(storeSupplier));
+                               .join(users, (ranking, user) -> UserRanking.of(
+                                               user.getFirstName(),
+                                               user.getLastName(),
+                                               ranking.getEntries()))
+                               .toTable(
+                                               Materialized
+                                                               .<String, UserRanking>as(storeSupplier)
+                                                               .withValueSerde(new JsonSerde().copyWithType(UserRanking.class)));
 
                Topology topology = builder.build();
                log.info("\n\n{}", topology.describe());
@@ -111,20 +95,7 @@ public class QueryStreamProcessor
 
        public Optional<UserRanking> getUserRanking(String username)
        {
-               return
-                               Optional
-                                               .ofNullable(getStore().get(username))
-                                               .map(json ->
-                                               {
-                                                       try
-                                                       {
-                                                               return mapper.readValue(json, UserRanking.class);
-                                                       }
-                                                       catch (JsonProcessingException e)
-                                                       {
-                                                               throw new RuntimeException(e);
-                                                       }
-                                               });
+               return Optional.ofNullable(getStore().get(username));
        }
 
        @PostConstruct