Hello World, using printer KR203 and JAVA

Hi, I try to send a Hello World to a thermal printer Zebra model KR203, these printers use the language KPL (Kiosk Printer Language), when printing a test page sale correctly but with my code stays in: "Printing ...", I can´t use the link-os-sdk because is not compatible with these type of printers this is my code:

 

    public void Print() {

        PrintService printService = PrintServiceLookup.lookupDefaultPrintService(); //Here ZEBRA KR203 Is default printer

        PrintRequestAttributeSet attributeSet = new HashPrintRequestAttributeSet();

        System.out.println("Default Printer :" + printService);

        String kplcommand = "<ESC>P<N1>\r\n"; // In this line try print test page

        byte[] by = kplcommand .getBytes();

        DocFlavor flavor = DocFlavor.BYTE_ARRAY.AUTOSENSE;

        Doc doc = new SimpleDoc(by, flavor, null);

        DocPrintJob job = printService.createPrintJob();

        try {

            job.print(doc, null);

            //job.print(doc, attributeSet);

        } catch (PrintException e) {

            System.out.println("e " + e);

        }

    }