stanfordnlp/CoreNLP · error · IllegalArgumentException

Directory access problem for

Error message

Directory access problem for: ${path}

What it means

FilePathProcessor.processPath throws IllegalArgumentException when File.listFiles(filter) returns null on a directory, which the JVM does when the directory cannot be read (I/O error or access denied). It surfaces a filesystem access problem while recursively processing a path.

Solutions

1. Check canRead() on the path before processing and skip/report unreadable directories.
2. Run the process with sufficient filesystem permissions, or use a user with access to the target tree.
3. Verify the directory exists and is not concurrently deleted; handle races defensively.
4. Catch IllegalArgumentException around processPath and log/skip the offending path instead of aborting the whole walk.

Example fix

// before
FilePathProcessor.processPath(new File("/root/secure"), filter, proc);
// after
File dir = new File("/root/secure");
if (dir.isDirectory() && dir.canRead()) {
  FilePathProcessor.processPath(dir, filter, proc);
} else {
  log.warn("Skipping unreadable directory: " + dir);
}

if (path.isDirectory() && !path.canRead()) { log.warn("Skipping unreadable: " + path); return; }

boolean isReadableDirectory(File f) { return f != null && f.isDirectory() && f.canRead(); }

try { FilePathProcessor.processPath(dir, filter, proc); } catch (IllegalArgumentException e) { log.warn("Skipping: " + e.getMessage()); }

When it happens

Trigger: Calling processPath on a directory the process lacks read permission for, a directory that vanished mid-walk, or an I/O error during listing.

Common situations: Running on paths owned by another user; restricted sandboxes/containers; walking system directories; race where the directory is deleted during traversal.

Understand the failure class

Background: Permission denied / not authorized / 403 Forbidden: access-control rejections when the caller lacks the required role, grant, or ownership — this error's family across 18 libraries.

Related errors

• Could not create directory <tgtDir.getAbsolutePath()>
• cp: could not list files in source
• Could not open temporary feature index file for writing.
• Could not open temporary feature index file for reading.
• Could not create directory <tgtDir.getAbsolutePath()>, as a…

AI-assisted analysis of stanfordnlp/CoreNLP@1b7edd19c4 (2026-09-10). Data as JSON: /api/errors/fd89c82483a463e1. Report an issue: GitHub.

Appendix: source

Thrown at src/edu/stanford/nlp/util/FilePathProcessor.java:76

   * filter are processed.  If the <code>path</code>is a file, then
   * that file is processed regardless of whether it satisfies the
   * filter.  (This semantics was adopted, since otherwise there was no
   * easy way to go through all the files in a directory without
   * descending recursively via the specification of a
   * <code>FileFilter</code>.)
   *
   * @param path      file or directory to load from
   * @param filter    a FileFilter of files to load.  The filter may be null,
   *     and then all files are processed.
   * @param processor The <code>FileProcessor</code> to apply to each
   *                  <code>File</code>
   */
  public static void processPath(File path, FileFilter filter, FileProcessor processor) {
    if (path.isDirectory()) {
      // if path is a directory, look into it
      File[] directoryListing = path.listFiles(filter);
      if (directoryListing == null) {
        throw new IllegalArgumentException("Directory access problem for: " + path);
      }
      for (File file : directoryListing) {
        processPath(file, filter, processor);
      }
    } else {
      // it's already passed the filter or was uniquely specified
      // if (filter.accept(path))
      processor.processFile(path);
    }
  }

}

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