/**
* Creates a new File instance by converting the given
* pathname string into an abstract pathname. If the given string is
* the empty string, then the result is the empty abstract pathname.
*
* @param pathname A pathname string
* @throws NullPointerException
* If the pathname argument is null
*/
public File(String pathname) {
//new function
initmaps();
if (pathname == null) {
throw new NullPointerException();
}
//new function
pathname=getVirtualPath(pathname);