调用Jasper报告时流损坏的异常

Question

我使用了一个fileDownloadActionListener来从ADF表单打开一个jasper报告。第一次，它正确打开。但第二次，它在应用程序上显示错误消息，“文件未下载或未正确下载。”

这是我的代码：

    public void reportAction(FacesContext ctx,OutputStream output) throws FileNotFoundException,NamingException,
                                     SQLException, IOException, JRException,
                                     ClassNotFoundException,
                                     InstantiationException,
                                     IllegalAccessException,StreamCorruptedException {
    File input = null;
    Connection conn = null;
    String branchId = getBranchId().getValue().toString();
    Map reportParameters = new HashMap();
    reportParameters.put("branchId", branchId);
    bindings = this.getBindings();
    ctx = FacesContext.getCurrentInstance();
    HttpServletResponse response = (HttpServletResponse)ctx.getExternalContext().getResponse();
    ServletOutputStream servletOutputStream;
    servletOutputStream = response.getOutputStream();
    String reportPath = ctx.getExternalContext().getInitParameter("reportpath");
    input = new File(reportPath+"testJob.jasper");
    byte[]  bytes= null;
    if(bindings!=null){
            OperationBinding ob = bindings.getOperationBinding("getCurrentConnection");
            ob.execute();
            conn = (Connection)ob.getResult();
    System.out.println("Report Path===========>"+input.getPath().toString());
    if(input.getPath()!=null&&reportParameters!=null&&conn!=null){
        JRPdfExporter pdfExporter = new JRPdfExporter();
        bytes = JasperRunManager.runReportToPdf(input.getPath(), reportParameters,  conn);
        JasperPrint print = JasperFillManager.fillReport(input.getPath(),reportParameters,conn);
        pdfExporter.setParameter(JRExporterParameter.JASPER_PRINT, print);
        pdfExporter.setParameter(JRExporterParameter.OUTPUT_FILE_NAME, input.getPath());
        pdfExporter.exportReport();
        response.addHeader("Content-disposition", "attachment;filename=testJob1.pdf");
        response.setContentType("application/pdf");
        response.setContentLength(bytes.length);
        File file = new File(input.getPath());
        output = response.getOutputStream();
        servletOutputStream.write(bytes, 0, bytes.length);
        FileInputStream fis = new FileInputStream(file);
         BufferedInputStream bui = new BufferedInputStream(fis);
         int readBytes = 0;
            while ((readBytes = bui.read()) != -1)
              output.write(readBytes);
        bui.close();
        fis.close();
        servletOutputStream.flush();
        servletOutputStream.close();
        ctx.responseComplete();
    }
}
else{
    ctx.addMessage(null,new FacesMessage("No bindings configured for this page"));
}
}