lingochamp/FileDownloader · error · InvalidParameterException

the provided mPath[ ] is invalid, can't find its directory

Error message

the provided mPath[%s] is invalid, can't find its directory

What it means

DownloadTaskHunter.prepare() throws InvalidParameterException when the task's target file path has no derivable parent directory (FileDownloadUtils.getParent returns null). The library must know which directory to create/manage the file in before downloading.

Solutions

1. Provide an absolute path including a valid directory, e.g. "/sdcard/download/file.zip".
2. Use FileDownloaderUtils or File(path, name) style construction to guarantee a parent directory.
3. Validate the path with FileDownloadUtils.getParent(path) != null before creating the task.

Example fix

// before
FileDownloader.getImpl().create(url, "");

// after
File file = new File(context.getExternalFilesDir(null), "file.zip");
FileDownloader.getImpl().create(url, file.getAbsolutePath());

String dir = FileDownloadUtils.getParent(path);
if (dir == null) throw new IllegalArgumentException("path needs a valid parent directory: " + path);

boolean hasValidParent(String p) { return p != null && FileDownloadUtils.getParent(p) != null; }

When it happens

Trigger: Passing a path with no directory component or a malformed path (e.g. empty string, null-ish path) to FileDownloader.create(url, path) where path is not itself a directory.

Common situations: Programmatically built paths from concatenation producing "" or "/file"-style paths; paths with invalid characters on the device filesystem.

Understand the failure class

Background: "Must be a positive integer", "Invalid value", "Unsupported": the invalid-argument-value error family, when a library rejects the value you pass — this error's family across 35 libraries.

Related errors

• If you start the task manually, it means this task doesn't…
• This task is running
• This task is dirty to restart, If you want to reuse this…
• Create parent directory failed, please make sure you have…
• Sorry, FileDownloader can not block the main thread…

AI-assisted analysis of lingochamp/FileDownloader@6237a8cac1 (2026-09-08). Data as JSON: /api/errors/74fbe702a1d82f09. Report an issue: GitHub.

Appendix: source

Thrown at library/src/main/java/com/liulishuo/filedownloader/DownloadTaskHunter.java:543

    private void prepare() throws IOException {
        final BaseDownloadTask.IRunningTask runningTask = mTask.getRunningTask();
        final BaseDownloadTask origin = runningTask.getOrigin();

        if (origin.getPath() == null) {
            origin.setPath(FileDownloadUtils.getDefaultSaveFilePath(origin.getUrl()));
            if (FileDownloadLog.NEED_LOG) {
                FileDownloadLog.d(this, "save Path is null to %s", origin.getPath());
            }
        }

        final File dir;
        if (origin.isPathAsDirectory()) {
            dir = new File(origin.getPath());
        } else {
            final String dirString = FileDownloadUtils.getParent(origin.getPath());
            if (dirString == null) {
                throw new InvalidParameterException(
                        FileDownloadUtils.formatString("the provided mPath[%s] is invalid,"
                                + " can't find its directory", origin.getPath()));
            }
            dir = new File(dirString);
        }

        if (!dir.exists()) {
            if (!dir.mkdirs() && !dir.exists()) {
                throw new IOException(FileDownloadUtils.
                        formatString("Create parent directory failed, please make sure "
                                        + "you have permission to create file or directory "
                                        + "on the path: %s",
                                dir.getAbsolutePath()));
            }
        }
    }

    private int getId() {

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