CsvDataSource should throw exceptions on error.

CHANGELOG.md

@@ -26,6 +26,7 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 - Improving column name validation to only run once per source [#849](https://github.com/ie3-institute/PowerSystemDataModel/issues/849)
 - Refactored and abstracted `EntitySource`s and `EntityData` creation [#969](https://github.com/ie3-institute/PowerSystemDataModel/issues/969)
 - Updated contributing.md [#737](https://github.com/ie3-institute/PowerSystemDataModel/issues/737)
+- `CsvDataSource` throws exceptions on error [#954](https://github.com/ie3-institute/PowerSystemDataModel/issues/954)
 
 ## [4.1.0] - 2023-11-02
 

src/main/java/edu/ie3/datamodel/io/connectors/CsvFileConnector.java

@@ -159,28 +159,7 @@ public synchronized <C extends UniqueEntity> void closeEntityWriter(Class<C> clz
   }
 
   /**
-   * Initializes a file reader for the given class that should be read in. The expected file name is
-   * determined based on {@link FileNamingStrategy} of the this {@link CsvFileConnector} instance
-   *
-   * @param clz the class of the entity that should be read
-   * @return the reader that contains information about the file to be read in
-   * @throws FileNotFoundException If the matching file cannot be found
-   */
-  public BufferedReader initReader(Class<? extends UniqueEntity> clz)
-      throws FileNotFoundException, ConnectorException {
-    Path filePath =
-        fileNamingStrategy
-            .getFilePath(clz)
-            .orElseThrow(
-                () ->
-                    new ConnectorException(
-                        "Cannot find a naming strategy for class '" + clz.getSimpleName() + "'."));
-    return initReader(filePath);
-  }
-
-  /**
-   * Initializes a file reader for the given file name. Use {@link
-   * CsvFileConnector#initReader(Class)} for files that actually correspond to concrete entities.
+   * Initializes a file reader for the given file name.
    *
    * @param filePath path of file starting from base folder, including file name but not file
    *     extension
@@ -247,18 +226,6 @@ private Set<Path> getIndividualTimeSeriesFilePaths() {
     }
   }
 
-  /**
-   * Initialises a reader to get grip on the file that contains mapping information between
-   * coordinate id and actual coordinate
-   *
-   * @return A {@link BufferedReader}
-   * @throws FileNotFoundException If the file is not present
-   */
-  public BufferedReader initIdCoordinateReader() throws FileNotFoundException {
-    Path filePath = Path.of(fileNamingStrategy.getIdCoordinateEntityName());
-    return initReader(filePath);
-  }
-
   /**
    * Builds a new file definition consisting of file name and head line elements
    *

src/main/java/edu/ie3/datamodel/io/source/DataSource.java

@@ -23,5 +23,6 @@ Optional<Set<String>> getSourceFields(Class<? extends UniqueEntity> entityClass)
       throws SourceException;
 
   /** Creates a stream of maps that represent the rows in the database */
-  Stream<Map<String, String>> getSourceData(Class<? extends UniqueEntity> entityClass);
+  Stream<Map<String, String>> getSourceData(Class<? extends UniqueEntity> entityClass)
+      throws SourceException;
 }

src/main/java/edu/ie3/datamodel/io/source/EntitySource.java

@@ -384,9 +384,14 @@ protected static Stream<Try<AssetInputEntityData, SourceException>> assetInputEn
    */
   protected Stream<Try<EntityData, SourceException>> buildEntityData(
       Class<? extends UniqueEntity> entityClass) {
-    return dataSource
-        .getSourceData(entityClass)
-        .map(fieldsToAttributes -> new Success<>(new EntityData(fieldsToAttributes, entityClass)));
+
+    return Try.of(() -> dataSource.getSourceData(entityClass), SourceException.class)
+        .convert(
+            data ->
+                data.map(
+                    fieldsToAttributes ->
+                        new Success<>(new EntityData(fieldsToAttributes, entityClass))),
+            exception -> Stream.of(Failure.of(exception)));
   }
 
   protected static <S extends UniqueEntity> Map<UUID, S> unpackMap(

src/main/java/edu/ie3/datamodel/io/source/TimeSeriesMappingSource.java

@@ -33,7 +33,7 @@ protected TimeSeriesMappingSource() {
    *
    * @return That mapping
    */
-  public Map<UUID, UUID> getMapping() {
+  public Map<UUID, UUID> getMapping() throws SourceException {
     return getMappingSourceData()
         .map(this::createMappingEntry)
         .filter(Try::isSuccess)
@@ -48,7 +48,7 @@ public Map<UUID, UUID> getMapping() {
    * @param modelIdentifier Identifier of the model
    * @return An {@link Optional} to the time series identifier
    */
-  public Optional<UUID> getTimeSeriesUuid(UUID modelIdentifier) {
+  public Optional<UUID> getTimeSeriesUuid(UUID modelIdentifier) throws SourceException {
     return Optional.ofNullable(getMapping().get(modelIdentifier));
   }
 
@@ -57,7 +57,7 @@ public Optional<UUID> getTimeSeriesUuid(UUID modelIdentifier) {
    *
    * @return Stream of maps
    */
-  public abstract Stream<Map<String, String>> getMappingSourceData();
+  public abstract Stream<Map<String, String>> getMappingSourceData() throws SourceException;
 
   /** Returns the option for fields found in the source */
   public abstract Optional<Set<String>> getSourceFields() throws SourceException;

src/main/java/edu/ie3/datamodel/io/source/csv/CsvDataSource.java

@@ -5,12 +5,14 @@
 */
 package edu.ie3.datamodel.io.source.csv;
 
-import edu.ie3.datamodel.exceptions.ConnectorException;
 import edu.ie3.datamodel.exceptions.SourceException;
 import edu.ie3.datamodel.io.connectors.CsvFileConnector;
 import edu.ie3.datamodel.io.naming.FileNamingStrategy;
 import edu.ie3.datamodel.io.source.DataSource;
 import edu.ie3.datamodel.models.UniqueEntity;
+import edu.ie3.datamodel.utils.Try;
+import edu.ie3.datamodel.utils.Try.Failure;
+import edu.ie3.datamodel.utils.Try.Success;
 import edu.ie3.datamodel.utils.validation.ValidationUtils;
 import edu.ie3.util.StringUtils;
 import java.io.BufferedReader;
@@ -46,6 +48,8 @@ public class CsvDataSource implements DataSource {
   protected final String csvSep;
   protected final CsvFileConnector connector;
 
+  private final FileNamingStrategy fileNamingStrategy;
+
   /**
    * @deprecated ensures downward compatibility with old csv data format. Can be removed when
    *     support for old csv format is removed. *
@@ -56,41 +60,38 @@ public class CsvDataSource implements DataSource {
   public CsvDataSource(String csvSep, Path folderPath, FileNamingStrategy fileNamingStrategy) {
     this.csvSep = csvSep;
     this.connector = new CsvFileConnector(folderPath, fileNamingStrategy);
+    this.fileNamingStrategy = fileNamingStrategy;
   }
 
   @Override
   public Optional<Set<String>> getSourceFields(Class<? extends UniqueEntity> entityClass)
       throws SourceException {
-    return getSourceFields(() -> connector.initReader(entityClass));
+    return getSourceFields(getFilePath(entityClass).getOrThrow());
   }
 
-  public Optional<Set<String>> getSourceFields(ReaderSupplier readerSupplier)
-      throws SourceException {
-    try (BufferedReader reader = readerSupplier.get()) {
+  /**
+   * @param filePath path of file starting from base folder, including file name but not file
+   *     extension
+   * @return The source field names as a set, if file exists
+   * @throws SourceException on error while reading the source file
+   */
+  public Optional<Set<String>> getSourceFields(Path filePath) throws SourceException {
+    try (BufferedReader reader = connector.initReader(filePath)) {
       return Optional.of(
           Arrays.stream(parseCsvRow(reader.readLine(), csvSep)).collect(Collectors.toSet()));
     } catch (FileNotFoundException e) {
       // A file not existing can be acceptable in many cases, and is handled elsewhere.
       log.debug("The source for the given entity couldn't be found! Cause: {}", e.getMessage());
       return Optional.empty();
-    } catch (ConnectorException | IOException e) {
+    } catch (IOException e) {
       throw new SourceException("Error while trying to read source", e);
     }
   }
 
-  public interface ReaderSupplier {
-    BufferedReader get() throws FileNotFoundException, ConnectorException;
-  }
-
   @Override
-  public Stream<Map<String, String>> getSourceData(Class<? extends UniqueEntity> entityClass) {
-    return buildStreamWithFieldsToAttributesMap(entityClass, connector);
-  }
-
-  // -=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-
-
-  public BufferedReader createReader(Path filePath) throws FileNotFoundException {
-    return connector.initReader(filePath);
+  public Stream<Map<String, String>> getSourceData(Class<? extends UniqueEntity> entityClass)
+      throws SourceException {
+    return buildStreamWithFieldsToAttributesMap(entityClass, true).getOrThrow();
   }
 
   // -=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-
@@ -279,25 +280,24 @@ protected <T extends UniqueEntity> Predicate<Optional<T>> isPresentCollectIfNot(
     };
   }
 
+  public FileNamingStrategy getNamingStrategy() {
+    return fileNamingStrategy;
+  }
+
   /**
-   * Tries to open a file reader from the connector based on the provided entity class and hands it
-   * over for further processing.
+   * Tries to open a file reader based on the provided entity class and hands it over for further
+   * processing.
    *
    * @param entityClass the entity class that should be build and that is used to get the
    *     corresponding reader
-   * @param connector the connector that should be used to get the reader from
    * @return a parallel stream of maps, where each map represents one row of the csv file with the
    *     mapping (fieldName to fieldValue)
    */
-  protected Stream<Map<String, String>> buildStreamWithFieldsToAttributesMap(
-      Class<? extends UniqueEntity> entityClass, CsvFileConnector connector) {
-    try {
-      return buildStreamWithFieldsToAttributesMap(entityClass, connector.initReader(entityClass));
-    } catch (FileNotFoundException | ConnectorException e) {
-      log.warn(
-          "Unable to find file for entity '{}': {}", entityClass.getSimpleName(), e.getMessage());
-    }
-    return Stream.empty();
+  protected Try<Stream<Map<String, String>>, SourceException> buildStreamWithFieldsToAttributesMap(
+      Class<? extends UniqueEntity> entityClass, boolean allowFileNotExisting) {
+    return getFilePath(entityClass)
+        .flatMap(
+            path -> buildStreamWithFieldsToAttributesMap(entityClass, path, allowFileNotExisting));
   }
 
   /**
@@ -306,13 +306,13 @@ protected Stream<Map<String, String>> buildStreamWithFieldsToAttributesMap(
    * the returning stream is a parallel stream, the order of the elements cannot be guaranteed.
    *
    * @param entityClass the entity class that should be build
-   * @param bufferedReader the reader to use
-   * @return a parallel stream of maps, where each map represents one row of the csv file with the
-   *     mapping (fieldName to fieldValue)
+   * @param filePath the path of the file to read
+   * @return a try containing either a parallel stream of maps, where each map represents one row of
+   *     the csv file with the mapping (fieldName to fieldValue) or an exception
    */
-  protected Stream<Map<String, String>> buildStreamWithFieldsToAttributesMap(
-      Class<? extends UniqueEntity> entityClass, BufferedReader bufferedReader) {
-    try (BufferedReader reader = bufferedReader) {
+  protected Try<Stream<Map<String, String>>, SourceException> buildStreamWithFieldsToAttributesMap(
+      Class<? extends UniqueEntity> entityClass, Path filePath, boolean allowFileNotExisting) {
+    try (BufferedReader reader = connector.initReader(filePath)) {
       final String[] headline = parseCsvRow(reader.readLine(), csvSep);
 
       // by default try-with-resources closes the reader directly when we leave this method (which
@@ -322,14 +322,31 @@ protected Stream<Map<String, String>> buildStreamWithFieldsToAttributesMap(
       Collection<Map<String, String>> allRows = csvRowFieldValueMapping(reader, headline);
 
       return distinctRowsWithLog(
-          allRows, fieldToValues -> fieldToValues.get("uuid"), entityClass.getSimpleName(), "UUID")
-          .parallelStream();
+              allRows,
+              fieldToValues -> fieldToValues.get("uuid"),
+              entityClass.getSimpleName(),
+              "UUID")
+          .map(Set::parallelStream);
+    } catch (FileNotFoundException e) {
+      if (allowFileNotExisting) {
+        log.warn("Unable to find file '{}': {}", filePath, e.getMessage());
+        return Success.of(Stream.empty());
+      } else {
+        return Failure.of(new SourceException("Unable to find file '" + filePath + "'.", e));
+      }
     } catch (IOException e) {
-      log.warn(
-          "Cannot read file to build entity '{}': {}", entityClass.getSimpleName(), e.getMessage());
+      return Failure.of(
+          new SourceException(
+              "Cannot read file to build entity '" + entityClass.getSimpleName() + "'", e));
     }
+  }
 
-    return Stream.empty();
+  private Try<Path, SourceException> getFilePath(Class<? extends UniqueEntity> entityClass) {
+    return Try.from(
+        fileNamingStrategy.getFilePath(entityClass),
+        () ->
+            new SourceException(
+                "Cannot find a naming strategy for class '" + entityClass.getSimpleName() + "'."));
   }
 
   protected List<Map<String, String>> csvRowFieldValueMapping(
@@ -358,10 +375,10 @@ protected List<Map<String, String>> csvRowFieldValueMapping(
    *     debug String)
    * @param keyDescriptor Colloquial descriptor of the key, that is meant to be unique (for debug
    *     String)
-   * @return either a set containing only unique rows or an empty set if at least two rows with the
-   *     same UUID but different field values exist
+   * @return a try of either a set containing only unique rows or an exception if at least two rows
+   *     with the same UUID but different field values exist
    */
-  protected Set<Map<String, String>> distinctRowsWithLog(
+  protected Try<Set<Map<String, String>>, SourceException> distinctRowsWithLog(
       Collection<Map<String, String>> allRows,
       final Function<Map<String, String>, String> keyExtractor,
       String entityDescriptor,
@@ -385,18 +402,19 @@ protected Set<Map<String, String>> distinctRowsWithLog(
       allRowsSet.removeAll(distinctIdSet);
       String affectedCoordinateIds =
           allRowsSet.stream().map(keyExtractor).collect(Collectors.joining(",\n"));
-      log.error(
-          """
-              '{}' entities with duplicated {} key, but different field values found! Please review the corresponding input file!
-              Affected primary keys:
-              {}""",
-          entityDescriptor,
-          keyDescriptor,
-          affectedCoordinateIds);
-      // if this happens, we return an empty set to prevent further processing
-      return new HashSet<>();
+
+      // if this happens, we return a failure
+      return Failure.of(
+          new SourceException(
+              "'"
+                  + entityDescriptor
+                  + "' entities with duplicated "
+                  + keyDescriptor
+                  + " key, but different field "
+                  + "values found! Please review the corresponding input file! Affected primary keys: "
+                  + affectedCoordinateIds));
     }
 
-    return allRowsSet;
+    return Success.of(allRowsSet);
   }
 }