void xyzAppPrint  (String printerName, String fileName)  
     throws IOException {
     try {
          DSContext ctx = new InitialDSContext();
          Printer prt = (Printer) ctx.lookup(printerName);
          prt.print (new FileInputStream (fileName));
     } catch (NamingException e {
          System.err.println("Unable to locate printer:" + e);
     } catch (ClassCastException e) {
          System.err.println(printerName + "not a printer");
     }

}