Merge pull request #1450 from ie3-institute/ps/#1445-CsvToFile

Generalize CSV->File

Author: sebastian-peter

CHANGELOG.md

@@ -25,6 +25,7 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 - Extend `GermanVoltageLevelUtils` with more synonymousIds [#143](https://github.com/ie3-institute/PowerSystemDataModel/issues/143)
 - Change spotless to use googleJavaFormat('1.28.0') [#1409](https://github.com/ie3-institute/PowerSystemDataModel/issues/1409)
 - Change `TimeSeries` to no longer extend `UniqueEntity` [#1441](https://github.com/ie3-institute/PowerSystemDataModel/issues/1441)
+- Refactor CSV handling into shared file-based infrastructure. [#1450](https://github.com/ie3-institute/PowerSystemDataModel/issues/1445)
 
 ## [8.1.0] - 2025-07-25
 

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

@@ -29,28 +29,19 @@
  * @version 0.1
  * @since 19.03.20
  */
-public class CsvFileConnector implements DataConnector {
+public class CsvFileConnector extends FileConnector {
   private static final Logger log = LoggerFactory.getLogger(CsvFileConnector.class);
 
   private final Map<Class<? extends Entity>, BufferedCsvWriter> entityWriters = new HashMap<>();
   private final Map<UUID, BufferedCsvWriter> timeSeriesWriters = new HashMap<>();
-  private final Path baseDirectory;
-  private final Optional<Function<String, InputStream>> customInputStream;
   private static final String FILE_ENDING = ".csv";
 
   public CsvFileConnector(Path baseDirectory) {
-    this.baseDirectory = baseDirectory;
-    this.customInputStream = Optional.empty();
+    super(baseDirectory);
   }
 
-  public CsvFileConnector(Path baseDirectory, Function<String, InputStream> inputStreamSupplier) {
-    this.baseDirectory = baseDirectory;
-    this.customInputStream = Optional.ofNullable(inputStreamSupplier);
-  }
-
-  /** Returns the base directory of this connector. */
-  public Path getBaseDirectory() {
-    return baseDirectory;
+  public CsvFileConnector(Path baseDirectory, Function<String, InputStream> customInputStream) {
+    super(baseDirectory, customInputStream);
   }
 
   public synchronized BufferedCsvWriter getOrInitWriter(
@@ -94,6 +85,19 @@ BufferedCsvWriter getOrInitWriter(T timeSeries, CsvFileDefinition fileDefinition
     }
   }
 
+  /**
+   * Initializes a reader for the given file name.
+   *
+   * @param filePath path of file starting from base folder, including file name but not file
+   *     extension
+   * @return the reader that contains information about the file to be read in
+   * @throws FileNotFoundException if no file with the provided file name can be found
+   */
+  public BufferedReader initReader(Path filePath) throws FileNotFoundException {
+    InputStream inputStream = openInputStream(filePath);
+    return new BufferedReader(new InputStreamReader(inputStream, StandardCharsets.UTF_8), 16384);
+  }
+
   /**
    * Initializes a writer with the given base folder and file definition
    *
@@ -158,28 +162,6 @@ public synchronized <C extends Entity> void closeEntityWriter(Class<C> clz) thro
     }
   }
 
-  /**
-   * 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
-   * @return the reader that contains information about the file to be read in
-   * @throws FileNotFoundException if no file with the provided file name can be found
-   */
-  public BufferedReader initReader(Path filePath) throws FileNotFoundException {
-    Path fullPath = baseDirectory.resolve(filePath.toString() + FILE_ENDING);
-
-    InputStream inputStream;
-
-    if (customInputStream.isPresent()) {
-      inputStream = customInputStream.get().apply(fullPath.toString());
-    } else {
-      inputStream = new FileInputStream(fullPath.toFile());
-    }
-
-    return new BufferedReader(new InputStreamReader(inputStream, StandardCharsets.UTF_8), 16384);
-  }
-
   @Override
   public void shutdown() {
     Stream.of(entityWriters.values(), timeSeriesWriters.values())
@@ -193,4 +175,9 @@ public void shutdown() {
               }
             });
   }
+
+  @Override
+  protected String getFileEnding() {
+    return FILE_ENDING;
+  }
 }

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

@@ -0,0 +1,64 @@
+/*
+ * © 2025. TU Dortmund University,
+ * Institute of Energy Systems, Energy Efficiency and Energy Economics,
+ * Research group Distribution grid planning and operation
+*/
+package edu.ie3.datamodel.io.connectors;
+
+import java.io.FileInputStream;
+import java.io.FileNotFoundException;
+import java.io.InputStream;
+import java.nio.file.Path;
+import java.util.function.Function;
+
+/** Base connector for file-based sources and sinks. */
+public abstract class FileConnector implements DataConnector {
+
+  protected final Path baseDirectory;
+
+  /**
+   * Optional factory for custom input streams; may be {@code null} when using the default handling.
+   */
+  private final Function<String, InputStream> customInputStream;
+
+  protected FileConnector(Path baseDirectory) {
+    this(baseDirectory, null);
+  }
+
+  protected FileConnector(Path baseDirectory, Function<String, InputStream> customInputStream) {
+    this.baseDirectory = baseDirectory;
+    this.customInputStream = customInputStream;
+  }
+
+  /** Returns the base directory backing this connector. */
+  public Path getBaseDirectory() {
+    return baseDirectory;
+  }
+
+  /**
+   * Open an {@link InputStream} to the given file path (without file ending) relative to the base
+   * directory.
+   */
+  protected InputStream openInputStream(Path filePath) throws FileNotFoundException {
+    Path fullPath = resolveFilePath(filePath);
+    if (customInputStream != null) {
+      return customInputStream.apply(fullPath.toString());
+    }
+    return new FileInputStream(fullPath.toFile());
+  }
+
+  /** Resolve the path including the file ending relative to the base directory. */
+  protected Path resolveFilePath(Path filePath) {
+    String relativePath = filePath.toString();
+    if (!relativePath.endsWith(getFileEnding())) {
+      relativePath = relativePath + getFileEnding();
+    }
+    return baseDirectory.resolve(relativePath);
+  }
+
+  /** Returns the file ending (including the dot) handled by this connector. */
+  protected abstract String getFileEnding();
+
+  @Override
+  public void shutdown() {}
+}

src/main/java/edu/ie3/datamodel/io/csv/CsvLoadProfileMetaInformation.java

@@ -7,10 +7,10 @@
 
 import edu.ie3.datamodel.io.factory.EntityData;
 import edu.ie3.datamodel.io.factory.EntityFactory;
-import edu.ie3.datamodel.io.naming.TimeSeriesMetaInformation;
 import edu.ie3.datamodel.io.naming.timeseries.ColumnScheme;
 import edu.ie3.datamodel.io.naming.timeseries.IndividualTimeSeriesMetaInformation;
 import edu.ie3.datamodel.io.naming.timeseries.LoadProfileMetaInformation;
+import edu.ie3.datamodel.io.naming.timeseries.TimeSeriesMetaInformation;
 import java.util.Collections;
 import java.util.List;
 import java.util.Set;

src/main/java/edu/ie3/datamodel/io/factory/timeseries/TimeSeriesMetaInformationFactory.java

@@ -0,0 +1,36 @@
+/*
+ * © 2025. TU Dortmund University,
+ * Institute of Energy Systems, Energy Efficiency and Energy Economics,
+ * Research group Distribution grid planning and operation
+*/
+package edu.ie3.datamodel.io.file;
+
+import edu.ie3.datamodel.exceptions.ParsingException;
+import java.util.Arrays;
+import java.util.stream.Collectors;
+
+public enum FileType {
+  CSV(".csv");
+
+  public final String fileEnding;
+
+  FileType(String fileEnding) {
+    this.fileEnding = fileEnding;
+  }
+
+  public static FileType getFileType(String fileName) throws ParsingException {
+    FileType[] fileTypes = FileType.values();
+    return Arrays.stream(fileTypes)
+        .filter(f -> fileName.endsWith(f.fileEnding))
+        .findFirst()
+        .orElseThrow(
+            () ->
+                new ParsingException(
+                    "No file ending found for file '"
+                        + fileName
+                        + "'. Only supports file types: "
+                        + Arrays.stream(fileTypes)
+                            .map(t -> t.fileEnding)
+                            .collect(Collectors.joining(", "))));
+  }
+}

src/main/java/edu/ie3/datamodel/io/file/FileType.java

@@ -8,6 +8,7 @@
 import edu.ie3.datamodel.io.IoUtil;
 import edu.ie3.datamodel.io.naming.timeseries.IndividualTimeSeriesMetaInformation;
 import edu.ie3.datamodel.io.naming.timeseries.LoadProfileMetaInformation;
+import edu.ie3.datamodel.io.naming.timeseries.TimeSeriesMetaInformation;
 import edu.ie3.datamodel.models.Entity;
 import edu.ie3.datamodel.models.timeseries.TimeSeries;
 import edu.ie3.datamodel.models.timeseries.TimeSeriesEntry;

src/main/java/edu/ie3/datamodel/io/naming/FileNamingStrategy.java

@@ -3,44 +3,49 @@
  * Institute of Energy Systems, Energy Efficiency and Energy Economics,
  * Research group Distribution grid planning and operation
 */
-package edu.ie3.datamodel.io.csv;
+package edu.ie3.datamodel.io.naming.timeseries;
 
-import edu.ie3.datamodel.io.naming.timeseries.ColumnScheme;
-import edu.ie3.datamodel.io.naming.timeseries.IndividualTimeSeriesMetaInformation;
+import edu.ie3.datamodel.io.file.FileType;
 import java.nio.file.Path;
 import java.util.Objects;
 import java.util.UUID;
 
 /** Enhancing the {@link IndividualTimeSeriesMetaInformation} with the full path to csv file */
-public class CsvIndividualTimeSeriesMetaInformation extends IndividualTimeSeriesMetaInformation {
+public class FileIndividualTimeSeriesMetaInformation extends IndividualTimeSeriesMetaInformation {
   private final Path fullFilePath;
+  private final FileType fileType;
 
-  public CsvIndividualTimeSeriesMetaInformation(
-      UUID uuid, ColumnScheme columnScheme, Path fullFilePath) {
+  public FileIndividualTimeSeriesMetaInformation(
+      UUID uuid, ColumnScheme columnScheme, Path fullFilePath, FileType fileType) {
     super(uuid, columnScheme);
     this.fullFilePath = fullFilePath;
+    this.fileType = fileType;
   }
 
-  public CsvIndividualTimeSeriesMetaInformation(
-      IndividualTimeSeriesMetaInformation metaInformation, Path fullFilePath) {
-    this(metaInformation.getUuid(), metaInformation.getColumnScheme(), fullFilePath);
+  public FileIndividualTimeSeriesMetaInformation(
+      IndividualTimeSeriesMetaInformation metaInformation, Path fullFilePath, FileType fileType) {
+    this(metaInformation.getUuid(), metaInformation.getColumnScheme(), fullFilePath, fileType);
   }
 
   public Path getFullFilePath() {
     return fullFilePath;
   }
 
+  public FileType getFileType() {
+    return fileType;
+  }
+
   @Override
   public boolean equals(Object o) {
     if (this == o) return true;
-    if (!(o instanceof CsvIndividualTimeSeriesMetaInformation that)) return false;
+    if (!(o instanceof FileIndividualTimeSeriesMetaInformation that)) return false;
     if (!super.equals(o)) return false;
-    return fullFilePath.equals(that.fullFilePath);
+    return fullFilePath.equals(that.fullFilePath) && fileType.equals(that.fileType);
   }
 
   @Override
   public int hashCode() {
-    return Objects.hash(super.hashCode(), fullFilePath);
+    return Objects.hash(super.hashCode(), fullFilePath, fileType);
   }
 
   @Override
@@ -53,6 +58,8 @@ public String toString() {
         + ", fullFilePath='"
         + fullFilePath
         + '\''
+        + ", fileType="
+        + fileType
         + '}';
   }
 }