IOException - detail message all question marks

I want to createNewFile with a path but I got an IOException. The question is, the detailed message cannot be interpreted, I can only see a bunch of question marks.

I am with Windows 10 originally in Spanish, but with Chinese language pack installed. The java language already set to en and file encoding UTF-8:

java -version
Picked up _JAVA_OPTIONS: -Duser.country=US -Duser.language=en -Dfile.encoding=UTF-8
openjdk version "11" 2018-09-25
OpenJDK Runtime Environment 18.9 (build 11+28)
OpenJDK 64-Bit Server VM 18.9 (build 11+28, mixed mode)

Why? Only this exception cannot be read.

EDIT: tried to define the language as zh, but does not work.

Use this main class to reproduce it:

public class PromotionTargetFileHandlerMain {
    public static final String uploadingDir = String.join(File.separator,
            System.getProperty("user.dir"), "targets_csv");
    private static final File destDir = new File(uploadingDir);

    public static void main(String[] args) {
        createFileDestination("target.csv");
    }

    public static void createFileDestination(String filename) {
        if (!destDir.exists()) {
            try {
                Files.createDirectory(Path.of(uploadingDir));
            } catch (FileAlreadyExistsException e) {
                log.trace("File dir already exists: {}", uploadingDir);
            } catch (IOException e) {
                log.error("Cannot create temp file dir {}", uploadingDir, e);
                throw new RuntimeException(e);
            }
        }
        String saveLocation = String.join(File.separator,
                uploadingDir, filename
        );
        File saveFile = new File(saveLocation);
        if (saveFile.exists()) saveFile.delete();
        try {
            saveFile.createNewFile();   // <--------------- here IOException
        } catch (IOException e) {
            throw new RuntimeException(e);
        }
    }
}

I may found one solution: change locale in Windows 10 for non-Unicode applications in Control Panel. It was Spanish, but now I changed to Chinese, then I can see some localized message of other IO errors(cannot reproduce the same error in the question):

I found this:

> ...and .NET exception messages will be localized regardless of the intended recipient of the message.

So it leads me to believe that the process is like this:

• native OS level error message is always in Chinese
• and, due to OS locale setting for non-Unicode(why Java is considered non-Unicode application, I don't know), it wants to interprete it as Spanish, but failed
• so I can only see ??????

In Windows 10, you can type "Control Panel" in the search bar, and go to: Region -> Management(tab) -> non-Unicode application language, set to Chinese(or others as in your local language pack), and restart.

Of course, it affects other non-Unicode application, too.

Write your code in try catch blog and in catch (Exception e) then if your file objecct has no issues then you will get the results

  try{
//code
}catch(Exception e){

println("Exception"+e)
}