Use nio paths instead of strings

.gitattributes

@@ -3,3 +3,4 @@
 src/test/resources/edu/ie3/datamodel/io/source/influxdb/_weather/cosmo/weather.txt eol=lf
 src/test/resources/edu/ie3/datamodel/io/source/influxdb/_weather/icon/weather.txt eol=lf
 
+gradlew eol=lf

CHANGELOG.md

@@ -19,6 +19,7 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 - Removing deprecated classes and methods [#540](https://github.com/ie3-institute/PowerSystemDataModel/issues/540)
 - Refactor CSV data sources [#716](https://github.com/ie3-institute/PowerSystemDataModel/issues/716)
 - Deleted parameter initFiles, set parameter append to false by default [#791](https://github.com/ie3-institute/PowerSystemDataModel/issues/791)
+- Use nio paths instead of strings for file path [#723](https://github.com/ie3-institute/PowerSystemDataModel/issues/723)
 
 
 ## [3.0.0] - 2023-02-16

src/main/java/edu/ie3/datamodel/io/IoUtil.java

@@ -6,6 +6,8 @@
 package edu.ie3.datamodel.io;
 
 import java.io.File;
+import java.nio.file.Path;
+import java.util.Optional;
 
 public class IoUtil {
   public static final String FILE_SEPARATOR_REGEX = "[\\\\/]";
@@ -17,13 +19,34 @@ private IoUtil() {
   }
 
   /**
-   * Ensure to have harmonized file separator across the whole String. Will replace all occurences
-   * if "\" and "/" by the systems file separator
+   * Ensure to have harmonized file separator across the whole String. Will replace all occurrences
+   * of "\" and "/" by the systems file separator.
    *
    * @param in The String to harmonize
    * @return The harmonized String
    */
   public static String harmonizeFileSeparator(String in) {
     return in.replaceAll(FILE_SEPARATOR_REGEX, FILE_SEPARATOR_REPLACEMENT);
   }
+
+  /**
+   * Ensure to have harmonized file separator across the whole path. Will replace all occurrences *
+   * of "\" and "/" by the systems file separator.
+   *
+   * @param path the path to harmonize
+   * @return the harmonized path
+   */
+  public static Path harmonizeFileSeparator(Path path) {
+    return Path.of(IoUtil.harmonizeFileSeparator(path.toString()));
+  }
+
+  /**
+   * Method to wrap a string of a path in an option for a path.
+   *
+   * @param in string of the path
+   * @return option of the path
+   */
+  public static Optional<Path> pathOption(String in) {
+    return Optional.of(Path.of(in));
+  }
 }

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

@@ -20,12 +20,10 @@
 import java.nio.charset.StandardCharsets;
 import java.nio.file.Files;
 import java.nio.file.Path;
-import java.nio.file.Paths;
 import java.util.*;
 import java.util.function.Function;
 import java.util.stream.Collectors;
 import java.util.stream.Stream;
-import org.apache.commons.io.FilenameUtils;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
@@ -44,11 +42,11 @@ public class CsvFileConnector implements DataConnector {
   private final Map<UUID, BufferedCsvWriter> timeSeriesWriters = new HashMap<>();
 
   private final FileNamingStrategy fileNamingStrategy;
-  private final String baseDirectoryName;
+  private final Path baseDirectoryName;
 
   private static final String FILE_ENDING = ".csv";
 
-  public CsvFileConnector(String baseDirectoryName, FileNamingStrategy fileNamingStrategy) {
+  public CsvFileConnector(Path baseDirectoryName, FileNamingStrategy fileNamingStrategy) {
     this.baseDirectoryName = baseDirectoryName;
     this.fileNamingStrategy = fileNamingStrategy;
   }
@@ -102,16 +100,15 @@ BufferedCsvWriter getOrInitWriter(T timeSeries, String[] headerElements, String
    * @throws ConnectorException If the base folder is a file
    * @throws IOException If the writer cannot be initialized correctly
    */
-  private BufferedCsvWriter initWriter(String baseDirectory, CsvFileDefinition fileDefinition)
+  private BufferedCsvWriter initWriter(Path baseDirectory, CsvFileDefinition fileDefinition)
       throws ConnectorException, IOException {
     /* Join the full DIRECTORY path (excluding file name) */
-    String baseDirectoryHarmonized = IoUtil.harmonizeFileSeparator(baseDirectory);
-    String fullDirectoryPath =
-        FilenameUtils.concat(baseDirectoryHarmonized, fileDefinition.directoryPath());
-    String fullPath = FilenameUtils.concat(baseDirectoryHarmonized, fileDefinition.getFilePath());
+    Path baseDirectoryHarmonized = IoUtil.harmonizeFileSeparator(baseDirectory);
+    Path fullDirectoryPath = baseDirectoryHarmonized.resolve(fileDefinition.getDirectoryPath());
+    Path fullPath = baseDirectoryHarmonized.resolve(fileDefinition.getFilePath());
 
     /* Create missing directories */
-    File directories = new File(fullDirectoryPath);
+    File directories = fullDirectoryPath.toFile();
     if (directories.isFile())
       throw new ConnectorException("Directory '" + directories + "' already exists and is a file!");
     if (!directories.exists() && !directories.mkdirs())
@@ -169,10 +166,10 @@ public synchronized <C extends UniqueEntity> void closeEntityWriter(Class<C> clz
    * @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 {
-    String filePath = null;
+  public BufferedReader initReader(Class<? extends UniqueEntity> clz)
+      throws FileNotFoundException, ConnectorException {
     try {
-      filePath =
+      Path filePath =
           fileNamingStrategy
               .getFilePath(clz)
               .orElseThrow(
@@ -181,13 +178,11 @@ public BufferedReader initReader(Class<? extends UniqueEntity> clz) throws FileN
                           "Cannot find a naming strategy for class '"
                               + clz.getSimpleName()
                               + "'."));
+      return initReader(filePath);
     } catch (ConnectorException e) {
-      log.error(
-          "Cannot get reader for entity '{}' as no file naming strategy for this file exists. Exception: {}",
-          clz.getSimpleName(),
-          e);
+      throw new ConnectorException(
+          "Cannot initialize reader for entity '" + clz.getSimpleName() + "'.", e);
     }
-    return initReader(filePath);
   }
 
   /**
@@ -198,8 +193,8 @@ public BufferedReader initReader(Class<? extends UniqueEntity> clz) throws FileN
    * @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(String filePath) throws FileNotFoundException {
-    File fullPath = new File(baseDirectoryName + File.separator + filePath + FILE_ENDING);
+  public BufferedReader initReader(Path filePath) throws FileNotFoundException {
+    File fullPath = baseDirectoryName.resolve(filePath.toString() + FILE_ENDING).toFile();
     return new BufferedReader(
         new InputStreamReader(new FileInputStream(fullPath), StandardCharsets.UTF_8), 16384);
   }
@@ -219,9 +214,9 @@ public BufferedReader initReader(String filePath) throws FileNotFoundException {
             filePath -> {
               /* Extract meta information from file path and enhance it with the file path itself */
               IndividualTimeSeriesMetaInformation metaInformation =
-                  fileNamingStrategy.individualTimeSeriesMetaInformation(filePath);
+                  fileNamingStrategy.individualTimeSeriesMetaInformation(filePath.toString());
               return new CsvIndividualTimeSeriesMetaInformation(
-                  metaInformation, FileNamingStrategy.removeFileNameEnding(filePath));
+                  metaInformation, FileNamingStrategy.removeFileNameEnding(filePath.getFileName()));
             })
         .filter(
             metaInformation ->
@@ -238,23 +233,20 @@ public BufferedReader initReader(String filePath) throws FileNotFoundException {
    *
    * @return A set of relative paths to time series files, with respect to the base folder path
    */
-  private Set<String> getIndividualTimeSeriesFilePaths() {
-    Path baseDirectoryPath =
-        Paths.get(
-            FilenameUtils.getFullPath(baseDirectoryName)
-                + FilenameUtils.getName(baseDirectoryName));
+  private Set<Path> getIndividualTimeSeriesFilePaths() {
+    Path baseDirectoryPath = baseDirectoryName.resolve(baseDirectoryName);
     try (Stream<Path> pathStream = Files.walk(baseDirectoryPath)) {
       return pathStream
           .map(baseDirectoryPath::relativize)
           .filter(
               path -> {
-                String withoutEnding = FileNamingStrategy.removeFileNameEnding(path.toString());
+                Path withoutEnding =
+                    Path.of(FileNamingStrategy.removeFileNameEnding(path.toString()));
                 return fileNamingStrategy
                     .getIndividualTimeSeriesPattern()
-                    .matcher(withoutEnding)
+                    .matcher(withoutEnding.toString())
                     .matches();
               })
-          .map(Path::toString)
           .collect(Collectors.toSet());
     } catch (IOException e) {
       log.error("Unable to determine time series files readers for time series.", e);
@@ -270,7 +262,7 @@ private Set<String> getIndividualTimeSeriesFilePaths() {
    * @throws FileNotFoundException If the file is not present
    */
   public BufferedReader initIdCoordinateReader() throws FileNotFoundException {
-    String filePath = fileNamingStrategy.getIdCoordinateEntityName();
+    Path filePath = Path.of(fileNamingStrategy.getIdCoordinateEntityName());
     return initReader(filePath);
   }
 
@@ -286,7 +278,7 @@ public BufferedReader initIdCoordinateReader() throws FileNotFoundException {
   private <T extends TimeSeries<E, V>, E extends TimeSeriesEntry<V>, V extends Value>
       CsvFileDefinition buildFileDefinition(T timeSeries, String[] headLineElements, String csvSep)
           throws ConnectorException {
-    String directoryPath = fileNamingStrategy.getDirectoryPath(timeSeries).orElse("");
+    Path directoryPath = fileNamingStrategy.getDirectoryPath(timeSeries).orElse(Path.of(""));
     String fileName =
         fileNamingStrategy
             .getEntityName(timeSeries)
@@ -309,7 +301,7 @@ CsvFileDefinition buildFileDefinition(T timeSeries, String[] headLineElements, S
   private CsvFileDefinition buildFileDefinition(
       Class<? extends UniqueEntity> clz, String[] headLineElements, String csvSep)
       throws ConnectorException {
-    String directoryPath = fileNamingStrategy.getDirectoryPath(clz).orElse("");
+    Path directoryPath = fileNamingStrategy.getDirectoryPath(clz).orElse(Path.of(""));
     String fileName =
         fileNamingStrategy
             .getEntityName(clz)

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

@@ -9,6 +9,7 @@
 import edu.ie3.util.StringUtils;
 import java.io.*;
 import java.nio.charset.StandardCharsets;
+import java.nio.file.Path;
 import java.util.Arrays;
 import java.util.Map;
 import java.util.Objects;
@@ -39,10 +40,11 @@ public class BufferedCsvWriter extends BufferedWriter {
    *     if no file exists, a new one will be created in both cases
    * @throws IOException If the FileOutputStream cannot be established.
    */
-  public BufferedCsvWriter(
-      String filePath, String[] headLineElements, String csvSep, boolean append)
+  public BufferedCsvWriter(Path filePath, String[] headLineElements, String csvSep, boolean append)
       throws IOException {
-    super(new OutputStreamWriter(new FileOutputStream(filePath, append), StandardCharsets.UTF_8));
+    super(
+        new OutputStreamWriter(
+            new FileOutputStream(filePath.toFile(), append), StandardCharsets.UTF_8));
     this.headLineElements = headLineElements;
     this.csvSep = csvSep;
   }
@@ -59,10 +61,10 @@ public BufferedCsvWriter(
    *     if no file exists, a new one will be created in both cases
    * @throws IOException If the FileOutputStream cannot be established.
    */
-  public BufferedCsvWriter(String baseFolder, CsvFileDefinition fileDefinition, boolean append)
+  public BufferedCsvWriter(Path baseFolder, CsvFileDefinition fileDefinition, boolean append)
       throws IOException {
     this(
-        baseFolder + File.separator + fileDefinition.getFilePath(),
+        baseFolder.resolve(fileDefinition.getFilePath()),
         fileDefinition.headLineElements(),
         fileDefinition.csvSep(),
         append);

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

@@ -5,63 +5,36 @@
 */
 package edu.ie3.datamodel.io.csv;
 
-import edu.ie3.datamodel.io.IoUtil;
+import edu.ie3.datamodel.utils.FileUtils;
+import java.nio.file.Path;
 import java.util.Arrays;
 import java.util.Objects;
-import java.util.regex.Matcher;
-import java.util.regex.Pattern;
-import org.apache.commons.io.FilenameUtils;
-import org.slf4j.Logger;
-import org.slf4j.LoggerFactory;
-
-public record CsvFileDefinition(
-    String fileName, String directoryPath, String[] headLineElements, String csvSep) {
-  private static final Logger logger = LoggerFactory.getLogger(CsvFileDefinition.class);
-
-  private static final Pattern FILE_NAME_PATTERN =
-      Pattern.compile(
-          "^(?<fileName>[^\\\\/\\s.]{0,255})(?:\\.(?<extension>[a-zA-Z0-9]{0,10}(?:\\.[a-zA-Z0-9]{0,10})?))?$");
-
-  private static final String FILE_EXTENSION = "csv";
 
+/**
+ * A definition of a csv file.
+ *
+ * @param filePath the path of the csv file (including filename and relative path)
+ * @param headLineElements elements of the headline of the defined file
+ * @param csvSep the separator that is used in this csv file
+ */
+public record CsvFileDefinition(Path filePath, String[] headLineElements, String csvSep) {
   public CsvFileDefinition(
-      String fileName, String directoryPath, String[] headLineElements, String csvSep) {
-    /* Remove all file separators at the beginning and end of a directory path and ensure harmonized file separator */
-    this.directoryPath =
-        Objects.nonNull(directoryPath)
-            ? IoUtil.harmonizeFileSeparator(
-                directoryPath
-                    .replaceFirst("^" + IoUtil.FILE_SEPARATOR_REGEX, "")
-                    .replaceAll(IoUtil.FILE_SEPARATOR_REGEX + "$", ""))
-            : "";
-
-    /* Check the given information of the file name */
-    Matcher matcher = FILE_NAME_PATTERN.matcher(fileName);
-    if (matcher.matches()) {
-      String extension = matcher.group("extension");
-      if (Objects.nonNull(extension) && !extension.equalsIgnoreCase(FILE_EXTENSION))
-        logger.warn(
-            "You provided a file name with extension '{}'. It will be overridden to '{}'.",
-            extension,
-            FILE_EXTENSION);
-      this.fileName = matcher.group("fileName") + "." + FILE_EXTENSION;
-    } else {
-      throw new IllegalArgumentException(
-          "The file name '"
-              + fileName
-              + "' is no valid file name. It may contain everything, except '/', '\\', '.' and any white space character.");
-    }
-
-    this.headLineElements = headLineElements;
-    this.csvSep = csvSep;
+      String fileName, Path directoryPath, String[] headLineElements, String csvSep) {
+    this(FileUtils.ofCsv(fileName, directoryPath), headLineElements, csvSep);
   }
 
   /**
    * @return The path to the file relative to a not explicitly defined base directory, including the
    *     file extension
    */
-  public String getFilePath() {
-    return !directoryPath.isEmpty() ? FilenameUtils.concat(directoryPath, fileName) : fileName;
+  public Path getFilePath() {
+    return filePath;
+  }
+
+  /** Returns the directory path of this file. */
+  public Path getDirectoryPath() {
+    Path parent = filePath.getParent();
+    return parent != null ? parent : Path.of("");
   }
 
   @Override
@@ -70,27 +43,23 @@ public boolean equals(Object o) {
     // records' equals method and array fields don't play together nicely
     if (this == o) return true;
     if (!(o instanceof CsvFileDefinition that)) return false;
-    return directoryPath.equals(that.directoryPath)
-        && fileName.equals(that.fileName)
+    return filePath.equals(that.filePath)
         && Arrays.equals(headLineElements, that.headLineElements)
         && csvSep.equals(that.csvSep);
   }
 
   @Override
   public int hashCode() {
-    int result = Objects.hash(directoryPath, fileName, csvSep);
+    int result = Objects.hash(filePath, csvSep);
     result = 31 * result + Arrays.hashCode(headLineElements);
     return result;
   }
 
   @Override
   public String toString() {
     return "CsvFileDefinition{"
-        + "directoryPath='"
-        + directoryPath
-        + '\''
-        + ", fileName='"
-        + fileName
+        + "fullPath='"
+        + filePath
         + '\''
         + ", headLineElements="
         + Arrays.toString(headLineElements)