Implemented a support for multiple data source types

java/com.sap.sailing.datamining/META-INF/MANIFEST.MF

@@ -15,7 +15,8 @@ Require-Bundle: com.sap.sailing.domain;bundle-version="1.0.0",
  com.sap.sse.datamining;bundle-version="1.0.0",
  com.sap.sse.datamining.shared;bundle-version="1.0.0",
  com.sap.sse,
- com.sap.sse.common
+ com.sap.sse.common,
+ org.eclipse.osgi
 Bundle-ClassPath: .
 Bundle-Activator: com.sap.sailing.datamining.Activator
 Bundle-ActivationPolicy: lazy

java/com.sap.sailing.datamining/src/com/sap/sailing/datamining/Activator.java

@@ -1,5 +1,6 @@
 package com.sap.sailing.datamining;
 
+import java.util.Collection;
 import java.util.HashSet;
 import java.util.Set;
 
@@ -14,6 +15,7 @@ import com.sap.sailing.datamining.data.HasTrackedLegOfCompetitorContext;
 import com.sap.sailing.datamining.data.HasTrackedRaceContext;
 import com.sap.sse.datamining.DataMiningBundleService;
 import com.sap.sse.datamining.DataRetrieverChainDefinition;
+import com.sap.sse.datamining.DataSourceProvider;
 import com.sap.sse.i18n.ResourceBundleStringMessages;
 import com.sap.sse.i18n.impl.ResourceBundleStringMessagesImpl;
 
@@ -24,13 +26,14 @@ public class Activator implements BundleActivator, DataMiningBundleService {
     private static Activator INSTANCE;
 
     private final ResourceBundleStringMessages sailingServerStringMessages;
-    private final SailingDataRetrieverChainDefinitions dataRetrieverChainDefinitions;
+    private final SailingDataRetrievalChainDefinitions dataRetrieverChainDefinitions;
     private final SailingClusterGroups clusterGroups;
+    private DataSourceProvider<?> racingEventServiceProvider;
     
     private ServiceReference<DataMiningBundleService> dataMiningBundleServiceReference;
     
     public Activator() {
-        dataRetrieverChainDefinitions = new SailingDataRetrieverChainDefinitions();
+        dataRetrieverChainDefinitions = new SailingDataRetrievalChainDefinitions();
         sailingServerStringMessages = new ResourceBundleStringMessagesImpl(STRING_MESSAGES_BASE_NAME, getClass().getClassLoader());
         clusterGroups = new SailingClusterGroups();
     }
@@ -38,6 +41,7 @@ public class Activator implements BundleActivator, DataMiningBundleService {
     @Override
     public void start(BundleContext context) throws Exception {
         INSTANCE = this;
+        racingEventServiceProvider = new RacingEventServiceProvider(context);
         
         dataMiningBundleServiceReference = context.registerService(DataMiningBundleService.class, this, null).getReference();
     }
@@ -68,6 +72,13 @@ public class Activator implements BundleActivator, DataMiningBundleService {
         return dataRetrieverChainDefinitions.getDataRetrieverChainDefinitions();
     }
     
+    @Override
+    public Iterable<DataSourceProvider<?>> getDataSourceProviders() {
+        Collection<DataSourceProvider<?>> dataSourceProviders = new HashSet<>();
+        dataSourceProviders.add(racingEventServiceProvider);
+        return dataSourceProviders;
+    }
+    
     public SailingClusterGroups getClusterGroups() {
         return clusterGroups;
     }

java/com.sap.sailing.datamining/src/com/sap/sailing/datamining/RacingEventServiceProvider.java

@@ -0,0 +1,29 @@
+package com.sap.sailing.datamining;
+
+import org.osgi.framework.BundleContext;
+import org.osgi.util.tracker.ServiceTracker;
+
+import com.sap.sailing.server.RacingEventService;
+import com.sap.sse.datamining.impl.AbstractDataSourceProvider;
+
+public class RacingEventServiceProvider extends AbstractDataSourceProvider<RacingEventService> {
+    
+    private final ServiceTracker<RacingEventService, RacingEventService> racingEventServiceTracker;
+
+    public RacingEventServiceProvider(BundleContext context) {
+        super(RacingEventService.class);
+        racingEventServiceTracker = createAndOpenRacingEventServiceTracker(context);
+    }
+
+    private ServiceTracker<RacingEventService, RacingEventService> createAndOpenRacingEventServiceTracker(BundleContext context) {
+        ServiceTracker<RacingEventService, RacingEventService> result = new ServiceTracker<>(context, RacingEventService.class.getName(), null);
+        result.open();
+        return result;
+    }
+
+    @Override
+    public RacingEventService getDataSource() {
+        return racingEventServiceTracker.getService();
+    }
+
+}

java/com.sap.sailing.datamining/src/com/sap/sailing/datamining/SailingDataRetrievalChainDefinitions.java

@@ -21,11 +21,11 @@ import com.sap.sailing.server.RacingEventService;
 import com.sap.sse.datamining.DataRetrieverChainDefinition;
 import com.sap.sse.datamining.impl.SimpleDataRetrieverChainDefinition;
 
-public class SailingDataRetrieverChainDefinitions {
+public class SailingDataRetrievalChainDefinitions {
 
     private final Collection<DataRetrieverChainDefinition<?, ?>> dataRetrieverChainDefinitions;
     
-    public SailingDataRetrieverChainDefinitions() {
+    public SailingDataRetrievalChainDefinitions() {
         dataRetrieverChainDefinitions = new ArrayList<>();
 
         final DataRetrieverChainDefinition<RacingEventService, HasTrackedLegOfCompetitorContext> trackedRaceRetrieverChainDefinition = new SimpleDataRetrieverChainDefinition<>(
@@ -55,7 +55,7 @@ public class SailingDataRetrieverChainDefinitions {
         dataRetrieverChainDefinitions.add(gpsFixRetrieverChainDefinition);
     }
 
-    public Collection<DataRetrieverChainDefinition<?, ?>> getDataRetrieverChainDefinitions() {
+    public Iterable<DataRetrieverChainDefinition<?, ?>> getDataRetrieverChainDefinitions() {
         return dataRetrieverChainDefinitions;
     }
 

java/com.sap.sailing.gwt.ui/src/main/java/com/sap/sailing/gwt/ui/server/DataMiningServiceImpl.java

@@ -34,16 +34,12 @@ public class DataMiningServiceImpl extends RemoteServiceServlet implements DataM
     private final BundleContext context;
     
     private final ServiceTracker<DataMiningServer, DataMiningServer> dataMiningServerTracker;
-    private final ServiceTracker<RacingEventService, RacingEventService> racingEventServiceTracker;
 
     private final FunctionDTOFactory functionDTOFactory;
     
     public DataMiningServiceImpl() {
         context = Activator.getDefault();
-        
         dataMiningServerTracker = createAndOpenDataMiningServerTracker(context);
-        racingEventServiceTracker = createAndOpenRacingEventServiceTracker(context);
-        
         functionDTOFactory = new FunctionDTOFactory();
     }
 
@@ -58,17 +54,6 @@ public class DataMiningServiceImpl extends RemoteServiceServlet implements DataM
     private DataMiningServer getDataMiningServer() {
         return dataMiningServerTracker.getService();
     }
-
-    private ServiceTracker<RacingEventService, RacingEventService> createAndOpenRacingEventServiceTracker(BundleContext context) {
-        ServiceTracker<RacingEventService, RacingEventService> result = new ServiceTracker<RacingEventService, RacingEventService>(
-                context, RacingEventService.class.getName(), null);
-        result.open();
-        return result;
-    }
-
-    private RacingEventService getRacingEventService() {
-        return racingEventServiceTracker.getService();
-    }
     
     @Override
     public Iterable<FunctionDTO> getAllStatistics(String localeInfoName) {
@@ -110,17 +95,17 @@ public class DataMiningServiceImpl extends RemoteServiceServlet implements DataM
     public Iterable<DataRetrieverChainDefinitionDTO> getDataRetrieverChainDefinitionsFor(FunctionDTO statisticToCalculate, String localeInfoName) {
         Class<?> baseDataType = getBaseDataType(statisticToCalculate);
         @SuppressWarnings("unchecked")
-        Iterable<DataRetrieverChainDefinition<RacingEventService, ?>> dataRetrieverChainDefinitions = (Iterable<DataRetrieverChainDefinition<RacingEventService,?>>)(Iterable<?>) getDataMiningServer().getDataRetrieverChainDefinitionsByDataType(baseDataType);
+        Iterable<DataRetrieverChainDefinition<?, ?>> dataRetrieverChainDefinitions = (Iterable<DataRetrieverChainDefinition<?, ?>>)(Iterable<?>)  getDataMiningServer().getDataRetrieverChainDefinitionsByDataType(baseDataType);
         return dataRetrieverChainDefinitionsAsDTOs(dataRetrieverChainDefinitions, localeInfoName);
     }
     
     private Collection<DataRetrieverChainDefinitionDTO> dataRetrieverChainDefinitionsAsDTOs(
-            Iterable<DataRetrieverChainDefinition<RacingEventService, ?>> dataRetrieverChainDefinitions, String localeInfoName) {
+            Iterable<DataRetrieverChainDefinition<?, ?>> dataRetrieverChainDefinitions, String localeInfoName) {
         Locale locale = ResourceBundleStringMessages.Util.getLocaleFor(localeInfoName);
         ResourceBundleStringMessages ServerStringMessages = getDataMiningServer().getStringMessages();
         
         Collection<DataRetrieverChainDefinitionDTO> DTOs = new ArrayList<>();
-        for (DataRetrieverChainDefinition<RacingEventService, ?> dataRetrieverChainDefinition : dataRetrieverChainDefinitions) {
+        for (DataRetrieverChainDefinition<?, ?> dataRetrieverChainDefinition : dataRetrieverChainDefinitions) {
             Collection<LocalizedTypeDTO> retrievedDataTypesChain = new ArrayList<>();
             for (DataRetrieverTypeWithInformation<?, ?> retrieverTypeWithInformation : dataRetrieverChainDefinition.getDataRetrieverTypesWithInformation()) {
                 String typeName = retrieverTypeWithInformation.getRetrievedDataType().getSimpleName();
@@ -142,7 +127,7 @@ public class DataMiningServiceImpl extends RemoteServiceServlet implements DataM
         DataRetrieverChainDefinition<RacingEventService, ?> retrieverChainDefinition = getDataMiningServer().getDataRetrieverChainDefinition(dataRetrieverChainDefinitionDTO.getId());
         Iterable<Function<?>> dimensions = functionDTOsAsFunctions(dimensionDTOs);
         Locale locale = ResourceBundleStringMessages.Util.getLocaleFor(localeInfoName);
-        Query<Set<Object>> dimensionValuesQuery = getDataMiningServer().createDimensionValuesQuery(getRacingEventService(), retrieverChainDefinition, retrieverLevel, dimensions, locale);
+        Query<Set<Object>> dimensionValuesQuery = getDataMiningServer().createDimensionValuesQuery(retrieverChainDefinition, retrieverLevel, dimensions, locale);
         QueryResult<Set<Object>> result = dimensionValuesQuery.run();
         return result;
     }
@@ -159,7 +144,7 @@ public class DataMiningServiceImpl extends RemoteServiceServlet implements DataM
     @Override
     public <ResultType extends Number> QueryResult<ResultType> runQuery(QueryDefinitionDTO queryDefinitionDTO) throws Exception {
         QueryDefinition<RacingEventService, ?, ResultType> queryDefinition = getDataMiningServer().getQueryDefinitionForDTO(queryDefinitionDTO);
-        Query<ResultType> query = getDataMiningServer().createQuery(getRacingEventService(), queryDefinition);
+        Query<ResultType> query = getDataMiningServer().createQuery(queryDefinition);
         QueryResult<ResultType> result = query.run();
         return result;
     }

java/com.sap.sse.datamining.test/src/com/sap/sse/datamining/impl/TestDataRetrieverChainDefinitionRegistry.java

@@ -10,6 +10,7 @@ import org.junit.Before;
 import org.junit.Test;
 
 import com.sap.sse.datamining.DataRetrieverChainDefinition;
+import com.sap.sse.datamining.DataRetrieverChainDefinitionRegistry;
 import com.sap.sse.datamining.components.Processor;
 import com.sap.sse.datamining.test.functions.registry.test_classes.Test_Regatta;
 import com.sap.sse.datamining.test.functions.registry.test_contexts.Test_HasLegOfCompetitorContext;

java/com.sap.sse.datamining/src/com/sap/sse/datamining/DataMiningBundleService.java

@@ -35,4 +35,9 @@ public interface DataMiningBundleService {
      */
     public Iterable<DataRetrieverChainDefinition<?, ?>> getDataRetrieverChainDefinitions();
 
+    /**
+     * @return a collection of {@link DataSourceProvider DataSourceProviders}, that are used to get the data sources for the queries
+     */
+    public Iterable<DataSourceProvider<?>> getDataSourceProviders();
+
 }

java/com.sap.sse.datamining/src/com/sap/sse/datamining/DataMiningServer.java

@@ -7,7 +7,6 @@ import java.util.concurrent.ExecutorService;
 
 import com.sap.sse.datamining.functions.Function;
 import com.sap.sse.datamining.functions.FunctionProvider;
-import com.sap.sse.datamining.impl.DataRetrieverChainDefinitionProvider;
 import com.sap.sse.datamining.shared.QueryDefinitionDTO;
 import com.sap.sse.datamining.shared.dto.FunctionDTO;
 import com.sap.sse.i18n.ResourceBundleStringMessages;
@@ -51,10 +50,9 @@ public interface DataMiningServer {
     
     public <DataSourceType, DataType, ResultType> QueryDefinition<DataSourceType, DataType, ResultType> getQueryDefinitionForDTO(QueryDefinitionDTO queryDefinitionDTO);
 
-    public <DataSource> Query<Set<Object>> createDimensionValuesQuery(DataSource dataSource,
-            DataRetrieverChainDefinition<DataSource, ?> dataRetrieverChainDefinition, int retrieverLevel,
+    public <DataSourceType> Query<Set<Object>> createDimensionValuesQuery(DataRetrieverChainDefinition<DataSourceType, ?> dataRetrieverChainDefinition, int retrieverLevel,
             Iterable<Function<?>> dimensions, Locale locale);
 
-    public <DataSource, DataType, ResultType> Query<ResultType> createQuery(DataSource dataSource, QueryDefinition<DataSource, DataType, ResultType> queryDefinition);
+    public <DataSourceType, ResultType> Query<ResultType> createQuery(QueryDefinition<DataSourceType, ?, ResultType> queryDefinition);
     
 }

java/com.sap.sse.datamining/src/com/sap/sse/datamining/DataRetrieverChainDefinitionProvider.java

@@ -1,10 +1,8 @@
-package com.sap.sse.datamining.impl;
+package com.sap.sse.datamining;
 
 import java.util.Collection;
 import java.util.UUID;
 
-import com.sap.sse.datamining.DataRetrieverChainDefinition;
-
 public interface DataRetrieverChainDefinitionProvider {
 
     public <DataSourceType> Collection<DataRetrieverChainDefinition<DataSourceType, ?>> getBySourceType(

java/com.sap.sse.datamining/src/com/sap/sse/datamining/DataRetrieverChainDefinitionRegistry.java

@@ -1,6 +1,5 @@
-package com.sap.sse.datamining.impl;
+package com.sap.sse.datamining;
 
-import com.sap.sse.datamining.DataRetrieverChainDefinition;
 
 public interface DataRetrieverChainDefinitionRegistry extends DataRetrieverChainDefinitionProvider {
 

java/com.sap.sse.datamining/src/com/sap/sse/datamining/DataSourceProvider.java

@@ -0,0 +1,9 @@
+package com.sap.sse.datamining;
+
+public interface DataSourceProvider<DataSourceType> {
+    
+    public Class<DataSourceType> getDataSourceType();
+    
+    public DataSourceType getDataSource();
+
+}

java/com.sap.sse.datamining/src/com/sap/sse/datamining/ModifiableDataMiningServer.java

@@ -14,6 +14,9 @@ public interface ModifiableDataMiningServer extends DataMiningServer {
     public void registerAllWithExternalFunctionPolicy(Iterable<Class<?>> externalClassesToScan);
 
     public void unregisterAllFunctionsOf(Iterable<Class<?>> classesToUnregister);
+    
+    public void setDataSourceProvider(DataSourceProvider<?> dataSourceProvider);
+    public void removeDataSourceProvider(DataSourceProvider<?> dataSourceProvider);
 
     public void registerDataRetrieverChainDefinition(DataRetrieverChainDefinition<?, ?> dataRetrieverChainDefinition);
     public void unregisterDataRetrieverChainDefinition(DataRetrieverChainDefinition<?, ?> dataRetrieverChainDefinition);

java/com.sap.sse.datamining/src/com/sap/sse/datamining/impl/AbstractDataSourceProvider.java

@@ -0,0 +1,18 @@
+package com.sap.sse.datamining.impl;
+
+import com.sap.sse.datamining.DataSourceProvider;
+
+public abstract class AbstractDataSourceProvider<DataSourceType> implements DataSourceProvider<DataSourceType> {
+    
+    private final Class<DataSourceType> dataSourceType;
+
+    public AbstractDataSourceProvider(Class<DataSourceType> dataSourceType) {
+        this.dataSourceType = dataSourceType;
+    }
+    
+    @Override
+    public Class<DataSourceType> getDataSourceType() {
+        return dataSourceType;
+    }
+
+}

java/com.sap.sse.datamining/src/com/sap/sse/datamining/impl/DataMiningActivator.java

@@ -17,6 +17,8 @@ import org.osgi.util.tracker.ServiceTrackerCustomizer;
 import com.sap.sse.datamining.DataMiningBundleService;
 import com.sap.sse.datamining.DataMiningServer;
 import com.sap.sse.datamining.DataRetrieverChainDefinition;
+import com.sap.sse.datamining.DataRetrieverChainDefinitionRegistry;
+import com.sap.sse.datamining.DataSourceProvider;
 import com.sap.sse.datamining.ModifiableDataMiningServer;
 import com.sap.sse.datamining.impl.functions.FunctionManager;
 import com.sap.sse.i18n.impl.ResourceBundleStringMessagesImpl;
@@ -75,6 +77,9 @@ public class DataMiningActivator implements BundleActivator {
         
         dataMiningServer.registerAllClasses(dataMiningBundleService.getClassesWithMarkedMethods());
         
+        for (DataSourceProvider<?> dataSourceProvider : dataMiningBundleService.getDataSourceProviders()) {
+            dataMiningServer.setDataSourceProvider(dataSourceProvider);
+        }
         for (DataRetrieverChainDefinition<?, ?> dataRetrieverChainDefinition : dataMiningBundleService.getDataRetrieverChainDefinitions()) {
             dataMiningServer.registerDataRetrieverChainDefinition(dataRetrieverChainDefinition);
         }
@@ -84,7 +89,11 @@ public class DataMiningActivator implements BundleActivator {
         dataMiningServer.removeStringMessages(dataMiningBundleService.getStringMessages());
         
         dataMiningServer.unregisterAllFunctionsOf(dataMiningBundleService.getClassesWithMarkedMethods());
+
         
+        for (DataSourceProvider<?> dataSourceProvider : dataMiningBundleService.getDataSourceProviders()) {
+            dataMiningServer.removeDataSourceProvider(dataSourceProvider);
+        }
         for (DataRetrieverChainDefinition<?, ?> dataRetrieverChainDefinition : dataMiningBundleService.getDataRetrieverChainDefinitions()) {
             dataMiningServer.unregisterDataRetrieverChainDefinition(dataRetrieverChainDefinition);
         }

java/com.sap.sse.datamining/src/com/sap/sse/datamining/impl/DataMiningServerImpl.java

@@ -2,6 +2,7 @@ package com.sap.sse.datamining.impl;
 
 import java.io.Serializable;
 import java.util.Collection;
+import java.util.HashMap;
 import java.util.Locale;
 import java.util.Map;
 import java.util.Map.Entry;
@@ -10,6 +11,9 @@ import java.util.UUID;
 import java.util.concurrent.ExecutorService;
 
 import com.sap.sse.datamining.DataRetrieverChainDefinition;
+import com.sap.sse.datamining.DataRetrieverChainDefinitionProvider;
+import com.sap.sse.datamining.DataRetrieverChainDefinitionRegistry;
+import com.sap.sse.datamining.DataSourceProvider;
 import com.sap.sse.datamining.ModifiableDataMiningServer;
 import com.sap.sse.datamining.Query;
 import com.sap.sse.datamining.QueryDefinition;
@@ -32,7 +36,8 @@ public class DataMiningServerImpl implements ModifiableDataMiningServer {
     private final FunctionRegistry functionRegistry;
     private final FunctionProvider functionProvider;
     
-    private DataRetrieverChainDefinitionRegistry dataRetrieverChainDefinitionRegistry;
+    private final Map<Class<?>, DataSourceProvider<?>> dataSourceProviderMappedByDataSourceType;
+    private final DataRetrieverChainDefinitionRegistry dataRetrieverChainDefinitionRegistry;
 
     public DataMiningServerImpl(ExecutorService executorService, FunctionRegistry functionRegistry, FunctionProvider functionProvider, DataRetrieverChainDefinitionRegistry dataRetrieverChainDefinitionRegistry) {
         this.stringMessages = new CompoundResourceBundleStringMessages();
@@ -40,6 +45,7 @@ public class DataMiningServerImpl implements ModifiableDataMiningServer {
         this.queryFactory = new QueryFactory();
         this.functionRegistry = functionRegistry;
         this.functionProvider = functionProvider;
+        dataSourceProviderMappedByDataSourceType = new HashMap<>();
         this.dataRetrieverChainDefinitionRegistry = dataRetrieverChainDefinitionRegistry;
     }
 
@@ -118,6 +124,16 @@ public class DataMiningServerImpl implements ModifiableDataMiningServer {
         return functionProvider.getFunctionForDTO(functionDTO);
     }
     
+    @Override
+    public void setDataSourceProvider(DataSourceProvider<?> dataSourceProvider) {
+        dataSourceProviderMappedByDataSourceType.put(dataSourceProvider.getDataSourceType(), dataSourceProvider);
+    }
+    
+    @Override
+    public void removeDataSourceProvider(DataSourceProvider<?> dataSourceProvider) {
+        dataSourceProviderMappedByDataSourceType.remove(dataSourceProvider.getDataSourceType());
+    }
+    
     @Override
     public DataRetrieverChainDefinitionProvider getDataRetrieverChainDefinitionProvider() {
         return dataRetrieverChainDefinitionRegistry;
@@ -190,15 +206,22 @@ public class DataMiningServerImpl implements ModifiableDataMiningServer {
     }
 
     @Override
-    public <DataSource, DataType, ResultType> Query<ResultType> createQuery(DataSource dataSource, QueryDefinition<DataSource, DataType, ResultType> queryDefinition) {
-        return queryFactory.createQuery(dataSource, queryDefinition, getStringMessages(), getExecutorService());
+    public <DataSourceType, ResultType> Query<ResultType> createQuery(QueryDefinition<DataSourceType, ?, ResultType> queryDefinition) {
+        DataSourceProvider<DataSourceType> dataSourceProvider = getDataSourceProviderFor(queryDefinition.getDataRetrieverChainDefinition().getDataSourceType());
+        return queryFactory.createQuery(dataSourceProvider.getDataSource(), queryDefinition, getStringMessages(), getExecutorService());
     }
 
     @Override
-    public <DataSource> Query<Set<Object>> createDimensionValuesQuery(DataSource dataSource,
-            DataRetrieverChainDefinition<DataSource, ?> dataRetrieverChainDefinition, int retrieverLevel,
+    public <DataSourceType> Query<Set<Object>> createDimensionValuesQuery(DataRetrieverChainDefinition<DataSourceType, ?> dataRetrieverChainDefinition, int retrieverLevel,
             Iterable<Function<?>> dimensions, Locale locale) {
-        return queryFactory.createDimensionValuesQuery(dataSource, dataRetrieverChainDefinition, retrieverLevel, dimensions, locale, getStringMessages(), getExecutorService());
+        DataSourceProvider<DataSourceType> dataSourceProvider = getDataSourceProviderFor(dataRetrieverChainDefinition.getDataSourceType());
+        return queryFactory.createDimensionValuesQuery(dataSourceProvider.getDataSource(), dataRetrieverChainDefinition, retrieverLevel, dimensions, locale, getStringMessages(), getExecutorService());
+    }
+
+    @SuppressWarnings("unchecked")
+    private <DataSourceType> DataSourceProvider<DataSourceType> getDataSourceProviderFor(Class<DataSourceType> dataSourceType) {
+        assert dataSourceProviderMappedByDataSourceType.containsKey(dataSourceType) : "No DataSourceProvider found for '" + dataSourceType + "'";
+        return (DataSourceProvider<DataSourceType>) dataSourceProviderMappedByDataSourceType.get(dataSourceType);
     }
     
 }

java/com.sap.sse.datamining/src/com/sap/sse/datamining/impl/SimpleDataRetrieverChainDefinitionRegistry.java

@@ -8,6 +8,7 @@ import java.util.Objects;
 import java.util.UUID;
 
 import com.sap.sse.datamining.DataRetrieverChainDefinition;
+import com.sap.sse.datamining.DataRetrieverChainDefinitionRegistry;
 
 public class SimpleDataRetrieverChainDefinitionRegistry implements DataRetrieverChainDefinitionRegistry {