Version default to 1 for get methods and increment for create (#50)

java/src/main/java/com/logicalclocks/hsfs/FeatureGroup.java

@@ -21,6 +21,7 @@
 import com.logicalclocks.hsfs.metadata.Query;
 import lombok.Builder;
 import lombok.Getter;
+import lombok.NonNull;
 import lombok.Setter;
 import org.apache.spark.sql.Dataset;
 import org.apache.spark.sql.Row;
@@ -78,16 +79,10 @@ public class FeatureGroup {
   private FeatureGroupEngine featureGroupEngine = new FeatureGroupEngine();
 
   @Builder
-  public FeatureGroup(FeatureStore featureStore, String name, Integer version, String description,
+  public FeatureGroup(FeatureStore featureStore, @NonNull String name, Integer version, String description,
                       List<String> primaryKeys, List<String> partitionKeys,
                       boolean onlineEnabled, Storage defaultStorage, List<Feature> features)
       throws FeatureStoreException {
-    if (name == null) {
-      throw new FeatureStoreException("Name is required when creating a feature group");
-    }
-    if (version == null) {
-      throw new FeatureStoreException("Version is required when creating a feature group");
-    }
 
     this.featureStore = featureStore;
     this.name = name;

java/src/main/java/com/logicalclocks/hsfs/FeatureStore.java

@@ -17,14 +17,18 @@
 
 import com.fasterxml.jackson.annotation.JsonProperty;
 import com.google.common.base.Strings;
+import com.logicalclocks.hsfs.engine.FeatureGroupEngine;
 import com.logicalclocks.hsfs.engine.SparkEngine;
 import com.logicalclocks.hsfs.metadata.FeatureGroupApi;
 import com.logicalclocks.hsfs.metadata.StorageConnectorApi;
 import com.logicalclocks.hsfs.metadata.TrainingDatasetApi;
 import lombok.Getter;
+import lombok.NonNull;
 import lombok.Setter;
 import org.apache.spark.sql.Dataset;
 import org.apache.spark.sql.Row;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
 
 import java.io.IOException;
 
@@ -45,27 +49,40 @@ public class FeatureStore {
   private TrainingDatasetApi trainingDatasetApi;
   private StorageConnectorApi storageConnectorApi;
 
+  private static final Logger LOGGER = LoggerFactory.getLogger(FeatureStore.class);
+
+  final Integer DEFAULT_VERSION = 1;
+
   public FeatureStore() throws FeatureStoreException {
     featureGroupApi = new FeatureGroupApi();
     trainingDatasetApi = new TrainingDatasetApi();
     storageConnectorApi = new StorageConnectorApi();
   }
 
   /**
-   * Get a feature group from the feature store
+   * Get a feature group object from the feature store
    * @param name: the name of the feature group
    * @param version: the version of the feature group
    * @return
    * @throws FeatureStoreException
    */
-  public FeatureGroup getFeatureGroup(String name, Integer version)
+  public FeatureGroup getFeatureGroup(@NonNull String name, @NonNull Integer version)
       throws FeatureStoreException, IOException {
-    if (Strings.isNullOrEmpty(name) || version == null) {
-      throw new FeatureStoreException("Both name and version are required");
-    }
     return featureGroupApi.get(this, name, version);
   }
 
+  /**
+   * Get a feature group object with default version `1` from the feature store
+   * @param name: the name of the feature group
+   * @return
+   * @throws FeatureStoreException
+   */
+  public FeatureGroup getFeatureGroup(String name) throws FeatureStoreException, IOException {
+    LOGGER.info("VersionWarning: No version provided for getting feature group `" + name + "`, defaulting to `" +
+      DEFAULT_VERSION + "`.");
+    return getFeatureGroup(name, DEFAULT_VERSION);
+  }
+
   public Dataset<Row> sql(String query) {
     return SparkEngine.getInstance().sql(query);
   }
@@ -93,14 +110,24 @@ public TrainingDataset.TrainingDatasetBuilder createTrainingDataset() {
    * @throws FeatureStoreException
    * @throws IOException
    */
-  public TrainingDataset getTrainingDataset(String name, Integer version)
+  public TrainingDataset getTrainingDataset(@NonNull String name, @NonNull Integer version)
       throws FeatureStoreException, IOException {
-    if (Strings.isNullOrEmpty(name) || version == null) {
-      throw new FeatureStoreException("Both name and version are required");
-    }
     return trainingDatasetApi.get(this, name, version);
   }
 
+  /**
+   * Get a training dataset object with the default version `1` from the selected feature store
+   * @param name: name of the training dataset
+   * @return
+   * @throws FeatureStoreException
+   * @throws IOException
+   */
+  public TrainingDataset getTrainingDataset(String name) throws FeatureStoreException, IOException {
+    LOGGER.info("VersionWarning: No version provided for getting training dataset `" + name + "`, defaulting to `" +
+      DEFAULT_VERSION + "`.");
+    return getTrainingDataset(name, DEFAULT_VERSION);
+  }
+
   @Override
   public String toString() {
     return "FeatureStore{" +

java/src/main/java/com/logicalclocks/hsfs/TrainingDataset.java

@@ -77,7 +77,7 @@ public class TrainingDataset {
   private TrainingDatasetEngine trainingDatasetEngine = new TrainingDatasetEngine();
 
   @Builder
-  public TrainingDataset(@NonNull String name, @NonNull Integer version, String description,
+  public TrainingDataset(@NonNull String name, Integer version, String description,
                          DataFormat dataFormat, StorageConnector storageConnector,
                          String location, List<Split> splits, Long seed,
                          FeatureStore featureStore) {

java/src/main/java/com/logicalclocks/hsfs/engine/FeatureGroupEngine.java

@@ -72,7 +72,15 @@ public void saveFeatureGroup(FeatureGroup featureGroup, Dataset<Row> dataset,
     }
 
     // Send Hopsworks the request to create a new feature group
-    featureGroupApi.save(featureGroup);
+    FeatureGroup apiFG = featureGroupApi.save(featureGroup);
+
+    if (featureGroup.getVersion() == null) {
+      LOGGER.info("VersionWarning: No version provided for creating feature group `" + featureGroup.getName() +
+        "`, incremented version to `" + apiFG.getVersion() + "`.");
+    }
+
+    // Update the original object - Hopsworks returns the incremented version
+    featureGroup.setVersion(apiFG.getVersion());
 
     // Write the dataframe
     saveDataframe(featureGroup, dataset, storage, SaveMode.Append, writeOptions);

java/src/main/java/com/logicalclocks/hsfs/engine/TrainingDatasetEngine.java

@@ -21,6 +21,8 @@
 import org.apache.spark.sql.Dataset;
 import org.apache.spark.sql.Row;
 import org.apache.spark.sql.SaveMode;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
 
 import java.io.IOException;
 import java.nio.file.Paths;
@@ -31,6 +33,8 @@ public class TrainingDatasetEngine {
   private TrainingDatasetApi trainingDatasetApi = new TrainingDatasetApi();
   private Utils utils = new Utils();
 
+  private static final Logger LOGGER = LoggerFactory.getLogger(TrainingDatasetEngine.class);
+
   //TODO:
   //      Compute statistics
 
@@ -50,8 +54,15 @@ public void save(TrainingDataset trainingDataset, Dataset<Row> dataset,
 
     // Make the rest call to create the training dataset metadata
     TrainingDataset apiTD = trainingDatasetApi.createTrainingDataset(trainingDataset);
-    // Update the original object - Hopsworks returns the full location
+
+    if (trainingDataset.getVersion() == null) {
+      LOGGER.info("VersionWarning: No version provided for creating training dataset `" + trainingDataset.getName() +
+        "`, incremented version to `" + apiTD.getVersion() + "`.");
+    }
+
+    // Update the original object - Hopsworks returns the full location and incremented version
     trainingDataset.setLocation(apiTD.getLocation());
+    trainingDataset.setVersion(apiTD.getVersion());
 
     // Build write options map
     Map<String, String> writeOptions =