Copier/coller le jar de son app [débutant]

String userHome = System.getProperty("user.home");
File downloadPath = new File(userHome, "Downloads");
System.out.println(downloadPath);

reg query "HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Explorer\User Shell Folders" /v {374DE290-123F-4565-9164-39C4925E467B}

public static String readRegistry(String path, String type, String name) {
    String[] cmdArray = { "reg", "query", path, "/v", name };
    try (Scanner sc = new Scanner(Runtime.getRuntime().exec(cmdArray).getInputStream())) {
        while (sc.hasNextLine()) {
            String line = sc.nextLine(), tab[] = line.split(Pattern.quote(type));
            if (tab.length == 2)
                return tab[1].trim();
        }
    } catch (Exception e) {
        e.printStackTrace();
    }
    return null;
}

String downloadPath = readRegistry("HKEY_CURRENT_USER\\Software\\Microsoft\\Windows\\CurrentVersion\\Explorer\\User Shell Folders",
"REG_EXPAND_SZ",
"{374DE290-123F-4565-9164-39C4925E467B}");