Java - imprimir directo a la impresora

import javax.print.Doc;

import javax.print.DocFlavor;

import javax.print.DocPrintJob;

import javax.print.PrintException;

import javax.print.PrintService;

import javax.print.PrintServiceLookup;

import javax.print.SimpleDoc;

public class ImpresionDirectaImpresora {

	public static void main(String[] args) {

		// TODO Auto-generated method stub

		String texto = "Esto es lo que va a la impresora";

		PrintService printService = PrintServiceLookup.lookupDefaultPrintService();

		DocFlavor flavor = DocFlavor.BYTE_ARRAY.AUTOSENSE;

		DocPrintJob docPrintJob = printService.createPrintJob();

		Doc doc = new SimpleDoc(texto.getBytes(), flavor, null);

		try {

			docPrintJob.print(doc, null);

		} catch (PrintException e) {

			// TODO Auto-generated catch block

			e.printStackTrace();

		}

	}

}

public static void imprimirComprobante(int nro){

    try{

	    Connection conn = null;

	    conn = conexion.obtenerConexion();

	    String dir= "DIRECCION REPORTE";

	    JasperReport reporteJasper = JasperCompileManager.compileReport(dir);

	    Map parametro = new HashMap();

	    parametro.put("@nro", nro);

	    JasperPrint mostrarReporte = JasperFillManager.fillReport(reporteJasper,parametro, conn);

	// ESTABLECE DATOS DE IMPRESORAS

	    PrinterJob job = PrinterJob.getPrinterJob();

	    PrintService[] services = PrintServiceLookup.lookupPrintServices(null, null);

	    int selectedService = 0;

	    for(int i = 0; i < services.length;i++){

	    if(services[i].getName().toUpperCase().contains('NOMBRE IMPRESORA')){

	    selectedService = i;

	    }

	    }

	      job.setPrintService(services[selectedService]);

	      PrintRequestAttributeSet printRequestAttributeSet = new HashPrintRequestAttributeSet();

	      MediaSizeName mediaSizeName = MediaSize.findMedia(4,4,MediaPrintableArea.INCH);

	      printRequestAttributeSet.add(mediaSizeName);

	      printRequestAttributeSet.add(new Copies(1));

	      JRPrintServiceExporter exporter;

	      exporter = new JRPrintServiceExporter();

	      exporter.setParameter(JRPrintServiceExporterParameter.PRINT_SERVICE, services[selectedService]);

	    exporter.setParameter(JRPrintServiceExporterParameter.PRINT_SERVICE_ATTRIBUTE_SET, services[selectedService].getAttributes());

	    exporter.setParameter(JRPrintServiceExporterParameter.PRINT_REQUEST_ATTRIBUTE_SET, printRequestAttributeSet);

	    exporter.setParameter(JRPrintServiceExporterParameter.DISPLAY_PAGE_DIALOG, Boolean.FALSE);

	    exporter.setParameter(JRPrintServiceExporterParameter.DISPLAY_PRINT_DIALOG, Boolean.FALSE);

	    exporter.setParameter(JRExporterParameter.JASPER_PRINT, mostrarReporte);

	    exporter.exportReport();

    }catch(JRException ex){

        JOptionPane.showMessageDialog(null, "Error de JREEXEPCION: " + ex);

    } catch (PrinterException ex) {

        JOptionPane.showMessageDialog(null,"ERROR PRINTEREXCEPCION " + ex);

    }

}