public static File makeTempDir() throws IOException {
  File temp=File.createTempFile("wwj",null);
  if (!temp.delete())   return null;
  if (!temp.mkdir())   return null;
  return temp;
}

public static File makeTempDir ( ) throws IOException { File temp = File . createTempFile ( "wwj" , null ) ; if ( ! temp . delete ( ) ) return null ; if ( ! temp . mkdir ( ) ) return null ; return temp ; }
create a directory in the computer ' s temp directory .
