Error exporting report to pdf

I have an error when exporting a report to pdf I am using Jasper Report 5.6.0 before the report I exported it well but now I do not want to do it and in the log I do not have any error this is the code to print

    public void PDF() throws JRException, IOException {
    EntityManagerFactory emf = Persistence.createEntityManagerFactory("plantaPU");
    EntityManager em = emf.createEntityManager();
    em.getEntityManagerFactory().getCache().evictAll();
    Query query = em.createQuery("select s from ticket s where s.id='" + ticketID + "'");
    List<ticket> listTicket = (List<ticket>) query.getResultList();
    JRBeanCollectionDataSource beanCollectionDataSource = new JRBeanCollectionDataSource(listTicket);
    String reportPath = FacesContext.getCurrentInstance().getExternalContext().getRealPath("/reports/report1.jasper");
    JasperPrint jasperPrint = JasperFillManager.fillReport(reportPath, new HashMap(), beanCollectionDataSource);
    HttpServletResponse httpServletResponse = (HttpServletResponse) FacesContext.getCurrentInstance().getExternalContext().getResponse();
    httpServletResponse.addHeader("Content-disposition", "attachment; filename=report.pdf");
    ServletOutputStream servletOutputStream;
    servletOutputStream = httpServletResponse.getOutputStream();
    JasperExportManager.exportReportToPdfStream(jasperPrint, servletOutputStream);
    FacesContext.getCurrentInstance().responseComplete();

}

and that's what I call from the page

  <p:commandButton value="Imprimir" action="#{verTicketController.PDF()}"/>