How to obtain OS directory

I,m looking f开发者_运维百科or some method that can let me obtain (in windows) the directory where windows is saved (for example in my PC it will return "C:\windows".

I need it because I have to call this method

public static void openFileWithNotepad(String pathFileTxt) throws InterruptedException, IOException
{
    if(System.getProperty("os.name").toUpperCase().contains("Windows".toUpperCase()))
    {
            String program = "C:/WINDOWS/system32/notepad.exe";
            Process p = Runtime.getRuntime().exec(program + " " + pathFileTxt);
    }
...
}

I want to use some method to switch "C:/WINDOWS" with the OS installation folder, in order to use this program on different pcs.

P.S.: If someone know, I'd like also to know how to use this method on UNIX OSs :)

Thank you for understanding!

Desktop.getDesktop().open(new File(pathFileTxt));

Works for any file for which there is an associated program, on any OS that supports Java 1.6+. See Desktop.open(File) for details.

i believe this should work:

System.getenv("WINDIR")

also, notepad doesn't tend to exist on unix, so i'm not sure where you are going with that...

try

System.getenv("windir") 

for windows.

I'm not sure about other OSs.

System.getenv("WINDIR") may work for you.