/**
 * 文件下载
 */
@RequestMapping("/downServiceAgreement")
public void downServiceAgreement(HttpServletRequest request, HttpServletResponse response){
    AuthCompanyUser user = CurrentUserHolder.getUser();
    assert user != null;
    try {
        // 文件的绝对路径
        String downCertApplyPath = orderService.downServiceAgreement();
        //告诉浏览器输出内容为流
        response.setContentType("application/octet-stream");
        response.setHeader("Content-Disposition", "attachment;fileName= " + URLEncoder.encode("文件名称", "utf-8") + ".pdf");
        OutputStream outputStream = response.getOutputStream();
        FileInputStream fileInputStream = new FileInputStream(downCertApplyPath);
        //缓存区
        byte[] buffer = new byte[1024];
        while (fileInputStream.read(buffer) != -1) {
            outputStream.write(buffer);
        }
        outputStream.flush();
        fileInputStream.close();
        outputStream.close();

        // 删除当前文件
        FileUtil.deleteFile(new File(downCertApplyPath));

    } catch (Exception e) {
        e.printStackTrace();
    }
}