Java - The name of the file is always 'null' when downloading it from server to my location

I have the following method to download files from a certain folder in my server.

public DefaultStreamedContent downloadFiles(String s) {
	try {
		File file = new File(s);
		
		InputStream is = new DefaultStreamedContent(new FileInputStream(file), Files.probeContentType(file.toPath())).getStream();
   	 	byte[] array = IOUtils.toByteArray(is);
   	 	
        return new DefaultStreamedContent(new ByteArrayInputStream(array));
	} catch (Exception e) {
		e.printStackTrace();
		return null;
	}
}

The code works well, as the files in the folder are downloaded correctly (I checked it´s contents). The problem is: The file name, when downloaded by the browser and saved in my Downloads folder locally, is always null. The files should have the same name of those files stored in the server. Let´s assume that the original file to be downloaded is server\folder1\folder2\file.extension. Why, when downloading it, the file name goes as null to my Downloads folder?

I thought that the file path is assumed as the file´s name, and therefore the Browser/OS saves it as null because slashes \ are not valid for file´s names.

How can I solve this?

Can you try something like this? Not sure if the Files.probeContentType(file.toPath() is required.

    public DefaultStreamedContent downloadFiles(String s) {
    try {
        File file = new File(s);
        String filename = file.getName();
        
        InputStream is = new DefaultStreamedContent(new FileInputStream(file), Files.probeContentType(file.toPath())).getStream();
        byte[] array = IOUtils.toByteArray(is);
        
        return new DefaultStreamedContent(new ByteArrayInputStream(array), filename);
    } catch (Exception e) {
        e.printStackTrace();
        return null;
    }
}

I solved my problem using this answer.
I basically copied the code and adapted to my needs. So, it works perfectly!