使用Servlet打开生成的PDF文件时出错

Question

通过使用以下代码打开PDF文件，我只是将文件写入servlet的输出流，但是，当我尝试打开该PDF文件时，它显示错误：“不是pdf或已损坏”< / p>

我的代码：

public void displayPj() {

    String url = ficheToDisplay.getUrl();
    String outPutFile = ficheToDisplay.getNom();

    HttpServletResponse resp = null;

    resp = (HttpServletResponse) FacesContext.getCurrentInstance()
            .getExternalContext().getResponse();
    File file = new File(url);
    resp.reset();
    resp.setHeader("Content-Disposition", "attachment; filename=\""
            + outPutFile + "\"");
    resp.setContentType("application/pdf;charset=UTF-8");
    resp.setHeader("Content-Length", String.valueOf(file.length()));

    BufferedInputStream input = null;
    BufferedOutputStream output = null;

    try {
        ServletOutputStream outStream = resp.getOutputStream();
        input = new BufferedInputStream(new FileInputStream(file),
                DEFAULT_BUFFER_SIZE);
        output = new BufferedOutputStream(resp.getOutputStream(),
                DEFAULT_BUFFER_SIZE);
        byte[] buffer = new byte[DEFAULT_BUFFER_SIZE];
        int length;
        while ((length = input.read(buffer)) > 0) {
            output.write(buffer, 0, length);
        }

        outStream.close();

    } catch (Exception e) {
        System.err
                .println("PROBLEM STREAMING DAILY REPORT PDF THROUGH RESPONSE!"
                        + e);
        e.printStackTrace();

        FacesMessage fm = new FacesMessage("Could Not Retrieve PDF.");
        FacesContext.getCurrentInstance().addMessage(
                "dailyReportArchiveFailure", fm);
    }

    FacesContext.getCurrentInstance().responseComplete();
}