I was asked by my client to print receipts on an Epson TM U220 (http://pos.epson.com/products/TM-U220.htm) from my web application. I have no idea how to do that. Are there
I created an app to write to a receipt printer for a POS system a while back. The way we did it was to just open a printwriter that pipes to the correct receipt printer. We manually sent the character codes to the printer to create bold, underline, font changes, etc because of requirements from the client that we do it that way (there was another application that used these character codes and they wanted us to use them also).
If you don't want to go through the manual process like I did a good choice is JavaPOS. It has got alot of stuff related to printing to receipt printers (definately much more elegant than I described above). You'll find it at http://www.javapos.com/.