private static final String JASPER_FILE_MOVIMENTI = "scalarePdf/pdf_movimenti.jrxml";
private static final String JASPER_FILE_SCALARE = "scalarePdf/pdf_scalare.jrxml";

@SuppressWarnings("rawtypes")
public byte[] rawPdf(BeScalare beScalare, String codTabulato, String output) throws JRException, IOException {

    JRBeanArrayDataSource dataSource = new JRBeanArrayDataSource(new Object[]{beScalare});

    //report's list
    List<byte[]> pdfFilesAsByteArray = new ArrayList<byte[]>();

    //Report one
    Class cScalare = this.getClass();
    ClassLoader clScalare = cScalare.getClassLoader();
    InputStream isScalare = clScalare.getResourceAsStream(JASPER_FILE_SCALARE);
    JasperDesign jasDesignScalare = JRXmlLoader.load(isScalare);
    //compile report one
    JasperReport reportScalare = JasperCompileManager.compileReport(jasDesignScalare);
    //parameters report one
    Map<String, Object> paramScalare = new HashMap<String, Object>();
    JRBeanCollectionDataSource itemsScalareSaldiPerValuta = new JRBeanCollectionDataSource(beScalare.getLstBeScalareSaldiPerValuta());
    paramScalare.put("scalareSaldiPerValuta", itemsScalareSaldiPerValuta);
    //fill report one
    JasperPrint jasperPrintScalare = JasperFillManager.fillReport(reportScalare, paramScalare, dataSource);
    pdfFilesAsByteArray.add(JasperExportManager.exportReportToPdf(jasperPrintScalare));

    //Report two
    Class c = this.getClass();
    ClassLoader cl = c.getClassLoader();
    InputStream is = cl.getResourceAsStream(JASPER_FILE_MOVIMENTI);
    JasperDesign jasDesign = JRXmlLoader.load(is);
    //compile report two
    JasperReport reportMovimenti = JasperCompileManager.compileReport(jasDesign);
    //parameters report two
    Map<String, Object> paramMovimenti = new HashMap<String, Object>();
    BufferedImage imgNumeroVerde = ImageIO.read(getClass().getResource("/scalarePdf/headphones.png"));
    paramMovimenti.put("numeroVerde", imgNumeroVerde);
    BufferedImage imgInternet = ImageIO.read(getClass().getResource("/scalarePdf/internet.png"));
    paramMovimenti.put("internet", imgInternet);
    JRBeanCollectionDataSource itemsScalareMovimenti = new JRBeanCollectionDataSource(beScalare.getLstBeScalareMovimenti());
    paramMovimenti.put("scalareMovimenti", itemsScalareMovimenti);
    //fill report two
    JasperPrint jasperPrintMovimenti = JasperFillManager.fillReport(reportMovimenti, paramMovimenti, dataSource);
    pdfFilesAsByteArray.add(JasperExportManager.exportReportToPdf(jasperPrintMovimenti));

    //merge the two reports in one
    ByteArrayOutputStream outStream = new ByteArrayOutputStream();
    Document document = null;
    PdfCopy writer = null;
    for (byte[] pdfByteArray : pdfFilesAsByteArray) {

        try {
            PdfReader reader = new PdfReader(pdfByteArray);
            int numberOfPages = reader.getNumberOfPages();

            if (document == null) {
                document = new Document(reader.getPageSizeWithRotation(1));
                writer = new PdfCopy(document, outStream); // new
                document.open();
            }
            PdfImportedPage page;
            for (int i = 0; i < numberOfPages;) {
                ++i;
                page = writer.getImportedPage(reader, i);
                writer.addPage(page);
            }
        }
        catch (Exception e) {
            e.printStackTrace();
        }
    }
    document.close();
    outStream.close();
    return outStream.toByteArray();
}

//Report two
dataSource.moveFirst();

//Report two
dataSource = new JRBeanArrayDataSource(new Object[]{beScalare});