apache/hadoop · error · IOException

invalid arguments to createHardLinkMult: filename list can b

Error message

invalid arguments to createHardLinkMult: filename list can be empty but not null

What it means

Error "invalid arguments to createHardLinkMult: filename list can be empty but not null" thrown in apache/hadoop.

Source

Thrown at hadoop-common-project/hadoop-common/src/main/java/org/apache/hadoop/fs/HardLink.java:203

   * directory, into one target directory.
   * @param parentDir - directory containing source files
   * @param fileBaseNames - list of path-less file names, as returned by 
   *                        parentDir.list()
   * @param linkDir - where the hardlinks should be put. It must already exist.
   * @throws IOException raised on errors performing I/O.
   */
  public static void createHardLinkMult(File parentDir, String[] fileBaseNames,
      File linkDir) throws IOException {
    if (parentDir == null) {
      throw new IOException(
          "invalid arguments to createHardLinkMult: parent directory is null");
    }
    if (linkDir == null) {
      throw new IOException(
          "invalid arguments to createHardLinkMult: link directory is null");
    }
    if (fileBaseNames == null) {
      throw new IOException(
          "invalid arguments to createHardLinkMult: "
          + "filename list can be empty but not null");
    }
    if (!linkDir.exists()) {
      throw new FileNotFoundException(linkDir + " not found.");
    }
    for (String name : fileBaseNames) {
      createLink(linkDir.toPath().resolve(name),
                 parentDir.toPath().resolve(name));
    }
  }

    /**
     * Determines whether the system supports hardlinks.
     * @param f - file to examine
     * @return true if hardlinks are supported, false otherwise
     */
  public static boolean supportsHardLink(File f) {

View on GitHub (pinned to 2add963021)

Solutions

1. Pass an empty array instead of null for the filename list.
2. Initialize the filename list before calling createHardLinkMult.

When it happens

Trigger: Thrown at hadoop-common-project/hadoop-common/src/main/java/org/apache/hadoop/fs/HardLink.java:203 when the library encounters an invalid state.

Common situations: See trigger scenarios.

AI-assisted analysis of apache/hadoop@2add963021 (2026-08-22). Data as JSON: /api/errors/a941f34bd7ee8577. Report an issue: GitHub.