两次单击命令按钮primefaces下载PDF

Question

我的xhtml是

 <h:form id="ibForm">
     <p:commandButton value="Yazdır" ajax="false"  action="#{islemiBitenlerBean.run_Rpr('PDF')}"  icon="ui-icon-print" immediate="true"/>
</h:form>

Backing bean是（会话范围）

public void run_Rpr(String tip) throws IOException, JRException, ClassNotFoundException, SQLException {
    HashMap m = new HashMap();
    m.put("belgeNo", selectedBelge.getBelgeNo());
    reports.preparetReport(RaporTuru.PDF, "reports//rapor//onaybelgesi.jrxml", "Onay Belgesi", m);
}

我的preparetReport方法是

public void preparetReport(RaporTuru tur, String filePath, String fileName, HashMap jasperParameter) throws JRException, IOException, ClassNotFoundException, SQLException {
    Connection connection;
    Class.forName("oracle.jdbc.OracleDriver");
    connection = DriverManager.getConnection("jdbc:oracle:thin:@--------", "----", "******");
    JasperReport jasperReport;
    JasperReport jasperReportSub;
    JasperPrint print;

    FacesContext faces = javax.faces.context.FacesContext.getCurrentInstance();
    HttpServletResponse response = (HttpServletResponse) faces.getExternalContext().getResponse();
    ServletContext servletContext = (ServletContext) faces.getExternalContext().getContext();
    String jrxmlFile = servletContext.getRealPath("/") + filePath;//raporumuzun yolu
    JasperDesign jasperDesign = JRXmlLoader.load(jrxmlFile);
    jasperReport = JasperCompileManager.compileReport(jasperDesign);

    print = JasperFillManager.fillReport(jasperReport, jasperParameter, connection);
    byte[] outData = JasperExportManager.exportReportToPdf(print);
    ByteArrayOutputStream rrtReport = new ByteArrayOutputStream();
    ServletOutputStream out = null;

    switch (tur) {
        case PDF:

            response.setContentType("application/pdf");
            response.setHeader("Content-disposition", "attachment; filename=" + fileName + ".pdf");
            response.getOutputStream().write(JasperExportManager.exportReportToPdf(print));//web sayfamızdan raporu çıkarttık
            faces.responseComplete();
            break;

    }

但我必须点击两次才能下载PDF。 有任何建议只需点击一下即可下载吗？