counter: 1.4.2 - RocksDB does nor work in Alpine-Linux

[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 324e424..455d895 100644 (file)
--- a/src/main/java/de/juplo/kafka/wordcount/counter/CounterStreamProcessor.java
+++ b/src/main/java/de/juplo/kafka/wordcount/counter/CounterStreamProcessor.java
@@ -1,24 +1,28 @@
 package de.juplo.kafka.wordcount.counter;
 
-import com.fasterxml.jackson.databind.ObjectMapper;
 import lombok.extern.slf4j.Slf4j;
-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.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.kstream.*;
+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;
 
 
@@ -26,14 +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);
        }
@@ -41,44 +43,22 @@ public class CounterStreamProcessor
        static Topology buildTopology(
                        String inputTopic,
                        String outputTopic,
-                       KeyValueBytesStoreSupplier storeSupplier,
-                       ObjectMapper mapper)
+                       KeyValueBytesStoreSupplier storeSupplier)
        {
                StreamsBuilder builder = new StreamsBuilder();
 
-               KStream<String, Word> source = builder.stream(
-                               inputTopic,
-                               Consumed.with(
-                                               Serdes.String(),
-                                               new JsonSerde<>(Word.class)
-                                                               .ignoreTypeHeaders()));
-
-               source
+               builder
+                               .stream(inputTopic, Consumed.with(inKeySerde(), inValueSerde()))
+                               .mapValues(word -> Word.of(word.getUser(), word.getWord()))
                                .map((key, word) -> new KeyValue<>(word, word))
-                               .groupByKey(Grouped.with(
-                                               new JsonSerde<>(Word.class)
-                                                               .forKeys()
-                                                               .noTypeInfo(),
-                                               new JsonSerde<>(Word.class)
-                                                               .noTypeInfo()))
-                               .count(Materialized
-                                               .<Word,Long>as(storeSupplier)
-                                               .withKeySerde(
-                                                               new JsonSerde<>(Word.class)
-                                                                               .forKeys()
-                                                                               .noTypeInfo())
-                                               .withValueSerde(
-                                                               Serdes.Long()))
+                               .groupByKey()
+                               .count(
+                                               Materialized
+                                                               .<Word, Long>as(storeSupplier)
+                                                               .withKeySerde(new JsonSerde<>(Word.class))) // No headers are present: fixed typing is needed!
                                .toStream()
-                               .map((word, count) -> new KeyValue<>(word, WordCount.of(word.getUser(), word.getWord(), count)))
-                               .to(
-                                               outputTopic,
-                                               Produced.with(
-                                                               new JsonSerde<>(Word.class)
-                                                                               .forKeys()
-                                                                               .noTypeInfo(),
-                                                               new JsonSerde<>(WordCount.class)
-                                                                               .noTypeInfo()));
+                               .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());
@@ -86,6 +66,11 @@ public class CounterStreamProcessor
                return topology;
        }
 
+       ReadOnlyKeyValueStore<Word, Long> getStore()
+       {
+               return streams.store(StoreQueryParameters.fromNameAndType(STORE_NAME, QueryableStoreTypes.keyValueStore()));
+       }
+
        public void start()
        {
                log.info("Starting Stream-Processor");
@@ -97,4 +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(","));
+       }
 }