Introduce generic interface for database storage

theodolite-benchmarks/uc1-flink/build.gradle

@@ -2,4 +2,8 @@ plugins {
   id 'theodolite.flink'
 }
 
+dependencies {
+    implementation project(':uc1-commons')
+}
+
 mainClassName = "theodolite.uc1.application.HistoryServiceFlinkJob"

theodolite-benchmarks/uc1-flink/src/main/java/theodolite/uc1/application/ConverterAdapter.java

+package theodolite.uc1.application;
+
+import org.apache.flink.api.common.functions.MapFunction;
+import rocks.theodolite.benchmarks.uc1.commons.RecordConverter;
+import titan.ccp.model.records.ActivePowerRecord;
+
+/**
+ * {@link MapFunction} which wraps a {@link RecordConverter} to be used with Flink.
+ */
+public class ConverterAdapter<T> implements MapFunction<ActivePowerRecord, T> {
+
+  private static final long serialVersionUID = -5263671231838353747L; // NOPMD
+
+  private final RecordConverter<T> recordConverter;
+
+  public ConverterAdapter(final RecordConverter<T> recordConverter) {
+    this.recordConverter = recordConverter;
+  }
+
+  @Override
+  public T map(final ActivePowerRecord record) throws Exception {
+    return this.recordConverter.convert(record);
+  }
+
+}

theodolite-benchmarks/uc1-flink/src/main/java/theodolite/uc1/application/HistoryServiceFlinkJob.java

@@ -7,6 +7,8 @@ import org.apache.flink.streaming.api.environment.StreamExecutionEnvironment;
 import org.apache.flink.streaming.connectors.kafka.FlinkKafkaConsumer;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
+import rocks.theodolite.benchmarks.uc1.commons.DatabaseAdapter;
+import rocks.theodolite.benchmarks.uc1.commons.logger.LogWriterFactory;
 import theodolite.commons.flink.KafkaConnectorFactory;
 import titan.ccp.common.configuration.ServiceConfigurations;
 import titan.ccp.model.records.ActivePowerRecord;
@@ -22,6 +24,8 @@ public final class HistoryServiceFlinkJob {
   private final StreamExecutionEnvironment env;
   private final String applicationId;
 
+  private final DatabaseAdapter<String> databaseAdapter = LogWriterFactory.forJson();
+
   /**
    * Create a new instance of the {@link HistoryServiceFlinkJob}.
    */
@@ -69,9 +73,10 @@ public final class HistoryServiceFlinkJob {
 
     stream
         // .rebalance()
-        .map(new GsonMapper())
-        .flatMap((record, c) -> LOGGER.info("Record: {}", record))
-        .returns(Types.GENERIC(Object.class)); // Will never be used
+        .map(new ConverterAdapter<>(this.databaseAdapter.getRecordConverter()))
+        .returns(Types.STRING)
+        .flatMap(new WriterAdapter<>(this.databaseAdapter.getDatabaseWriter()))
+        .returns(Types.VOID); // Will never be used
   }
 
   /**

theodolite-benchmarks/uc1-flink/src/main/java/theodolite/uc1/application/WriterAdapter.java

+package theodolite.uc1.application;
+
+import org.apache.flink.api.common.functions.FlatMapFunction;
+import org.apache.flink.util.Collector;
+import rocks.theodolite.benchmarks.uc1.commons.DatabaseAdapter;
+import rocks.theodolite.benchmarks.uc1.commons.DatabaseWriter;
+
+/**
+ * {@link FlatMapFunction} which wraps a {@link DatabaseAdapter} to be used with Flink.
+ */
+public class WriterAdapter<T> implements FlatMapFunction<T, Void> {
+
+  private static final long serialVersionUID = -5263671231838353747L; // NOPMD
+
+  private final DatabaseWriter<T> databaseWriter;
+
+  public WriterAdapter(final DatabaseWriter<T> databaseWriter) {
+    this.databaseWriter = databaseWriter;
+  }
+
+  @Override
+  public void flatMap(final T value, final Collector<Void> out) throws Exception {
+    this.databaseWriter.write(value);
+  }
+
+}

theodolite-benchmarks/uc1-kstreams/build.gradle

@@ -2,4 +2,8 @@ plugins {
   id 'theodolite.kstreams'
 }
 
+dependencies {
+    implementation project(':uc1-commons')
+}
+
 mainClassName = "theodolite.uc1.application.HistoryService"

theodolite-benchmarks/uc1-kstreams/src/main/java/theodolite/uc1/streamprocessing/TopologyBuilder.java

 package theodolite.uc1.streamprocessing;
 
-import com.google.gson.Gson;
 import java.util.Properties;
 import org.apache.kafka.common.serialization.Serdes;
 import org.apache.kafka.streams.StreamsBuilder;
 import org.apache.kafka.streams.Topology;
 import org.apache.kafka.streams.kstream.Consumed;
-import org.slf4j.Logger;
-import org.slf4j.LoggerFactory;
+import rocks.theodolite.benchmarks.uc1.commons.DatabaseAdapter;
+import rocks.theodolite.benchmarks.uc1.commons.logger.LogWriterFactory;
 import titan.ccp.common.kafka.avro.SchemaRegistryAvroSerdeFactory;
 import titan.ccp.model.records.ActivePowerRecord;
 
@@ -16,12 +15,11 @@ import titan.ccp.model.records.ActivePowerRecord;
  */
 public class TopologyBuilder {
 
-  private static final Logger LOGGER = LoggerFactory.getLogger(TopologyBuilder.class);
-  private static final Gson GSON = new Gson();
-
   private final String inputTopic;
   private final SchemaRegistryAvroSerdeFactory srAvroSerdeFactory;
 
+  private final DatabaseAdapter<String> databaseAdapter = LogWriterFactory.forJson();
+
   private final StreamsBuilder builder = new StreamsBuilder();
 
 
@@ -42,8 +40,8 @@ public class TopologyBuilder {
         .stream(this.inputTopic, Consumed.with(
             Serdes.String(),
             this.srAvroSerdeFactory.<ActivePowerRecord>forValues()))
-        .mapValues(v -> GSON.toJson(v))
-        .foreach((k, record) -> LOGGER.info("Record: {}", record));
+        .mapValues(this.databaseAdapter.getRecordConverter()::convert)
+        .foreach((k, record) -> this.databaseAdapter.getDatabaseWriter().write(record));
 
     return this.builder.build(properties);
   }