code: public static byte[] getPdf(JasperPrint jasperPrint) throws JRException {
          byte[] content = null;
          ByteArrayOutputStream baos = null;
          try {
              baos = new ByteArrayOutputStream();
              JRPdfExporter exporter = new JRPdfExporter();
              content = getBytes(exporter, baos, jasperPrint);
          } finally {
              if (baos != null) {
                  try {
                      baos.flush();
                      baos.close();
                  } catch (Exception e) {
                      e.printStackTrace();
                  }
              }
          }
          return content;
      }
docs: /*
  public static JasperPrint fillReport(File jasper, Map params, Connection conn) throws Exception {
  FileInputStream input = new FileInputStream(jasper);
  return JasperFillManager.fillReport(input, params, conn);
  }