Ireport + jsf + primefaces + erro ao gerar relatorio - RESOLVIDO

public String rodarPdf(){  
		FacesContext facesContext = FacesContext.getCurrentInstance();

		facesContext.responseComplete();

		List<Aluno> listaFuncionario = new ArrayList<Aluno>();

		listaFuncionario = ControleFactory.getInstance()
				.getAlunoscontrole().listaTodos(2013);

		JRBeanCollectionDataSource ds = new JRBeanCollectionDataSource(
				listaFuncionario); 
        Map<String, Object> parameters = new HashMap<String, Object>();  
          
        String arquivo = new UtilFaces().getServletContext().getRealPath("/WEB-INF/cart.jasper");  
        File reportFile = new File(arquivo);  
        byte[] bytes = null;  
        try{  
            bytes = JasperRunManager.runReportToPdf(reportFile.getPath(), parameters, ds);  
            launchPdfShow(bytes,false,"none");
        }catch(JRException e){  
            e.printStackTrace();  
        }            
        
        return "";
    }  




private void launchPdfShow(byte[] bytes,boolean isDownload,String fileName){  
        HttpServletResponse response = new UtilFaces().getResponse();  
        if (bytes != null && bytes.length > 0) {  
            ServletOutputStream ouputStream = null;  
            try {  
                response.setContentType("application/pdf");  
  
                if(isDownload)  
                    response.setHeader("Content-disposition", "attachment;filename="+fileName+".pdf");  
  
                response.setContentLength(bytes.length);  
                ouputStream = response.getOutputStream();  
                ouputStream.write(bytes, 0, bytes.length);  
                ouputStream.flush();  
                ouputStream.close();  
                new UtilFaces().getFacesContext().responseComplete();  
            } catch (IOException ex) {  
                ex.printStackTrace();  
            }  
         }  
    }

public class UtilFaces {  
	  
    public UtilFaces() {  
    }  
      
    public FacesContext getFacesContext() {  
        return FacesContext.getCurrentInstance();  
    }  
    public ExternalContext getExternalContext() {  
        return getFacesContext().getExternalContext();  
    }  
    public HttpServletRequest getRequest() {  
        return (HttpServletRequest) getExternalContext().getRequest();  
    }  
    public HttpServletResponse getResponse() {  
        return (HttpServletResponse) getExternalContext().getResponse();  
    }  
    public HttpSession getHttpSession(){  
        return (HttpSession) getFacesContext().getExternalContext().getSession(false);  
    }  
    public ServletContext getServletContext(){  
        return (ServletContext) getExternalContext().getContext();  
    }  
    public void msg(String destination,String msg){  
        FacesMessage message = new FacesMessage(msg);  
        getFacesContext().addMessage(destination, message);  
    }  
    public void addErrorMessage(Exception ex, String defaultMsg) {  
        String msg = ex.getLocalizedMessage();  
        if (msg != null && msg.length() > 0) {  
            addErrorMessage(msg);  
        } else {  
            addErrorMessage(defaultMsg);  
        }  
    }  
  
    public void addErrorMessages(List<String> messages) {  
        for (String message : messages) {  
            addErrorMessage(message);  
        }  
    }  
  
    public void addErrorMessage(String msg) {  
        FacesMessage facesMsg = new FacesMessage(FacesMessage.SEVERITY_ERROR, msg, msg);  
        FacesContext.getCurrentInstance().addMessage(null, facesMsg);  
    }  
  
    public  void addSuccessMessage(String msg) {  
        FacesMessage facesMsg = new FacesMessage(FacesMessage.SEVERITY_INFO, msg, msg);  
        FacesContext.getCurrentInstance().addMessage("successInfo", facesMsg);  
    }  
  
    public  void addWarnMessage(String msg) {  
        FacesMessage facesMsg = new FacesMessage(FacesMessage.SEVERITY_WARN, msg, msg);  
        FacesContext.getCurrentInstance().addMessage("warnInfo", facesMsg);  
    }  
  
    public  void addFatalMessage(String msg) {  
        FacesMessage facesMsg = new FacesMessage(FacesMessage.SEVERITY_FATAL, msg, msg);  
        FacesContext.getCurrentInstance().addMessage("fatalInfo", facesMsg);  
    }  
}

<script type="text/javascript">
			function action() {
				var form = document.forms[0];
				form.action = "#{cadloginBean.rodarPdf()}";
			}
		</script>