My program successfully creates and fills a Excel(.xls) file. Once created, I would like the new file to open in the system\'s default program (Excel in my case). How can I
You probably did the Runtime.exec incorrectly. Give this a look to see if that's the case.
If you just want to open an Excel file with Java, I'd recommend using Andy Khan's JExcel API. Perhaps using that with a Swing JTable will be just the ticket.