jar放在Ubuntu下运行，但是在windows下访问web下载文件出现两次下载

整个项目用的是spring Boot和layui

jar放在Ubuntu下运行，

然后我在Ubuntu下访问web页面下载文件，只下载一次这个正常。

如下图

然后，我在windows下访问web进行文件下载就会下载两次

如下图

下面是具体代码

JS的代码

$.ajax({
            type:"POST",
            url:"/result/checkFile",
            data : JSON.stringify(data),
            dataType:"json",
            contentType:"application/json",
            async: false,
            success:function (dataMap) {
                if(dataMap.code==200){
                    downLoad("/result/download?fileName="+dataMap.fileName)
                }else if (dataMap.code==404){
                    layer.msg("数据获取异常！");
                }else if(dataMap.code==400){
                    layer.open({
                        title: '提  示',
                        content: '登录失效',
                        end: function() {
                            window.location.href="/login";
                        }
                    });
                }
            }
        });

//传入参数src为文件地址
function  downLoad (src) {
    var download_file= {}
    if (typeof(download_file.iframe) == "undefined") {
        var iframe = document.createElement("iframe");
        download_file.iframe = iframe;
        document.body.appendChild(download_file.iframe);
    }
    download_file.iframe.src = src
    download_file.iframe.style.display = "none";
}

java后端的代码

@ResponseBody
    @RequestMapping(value = "/download")
    public void downloadFile(HttpServletResponse response, HttpServletRequest request) throws UnsupportedEncodingException {

        String fileName = (String) request.getParameter("fileName")+".xls"; //下载的文件名
        //System.out.printf((String) map.get("begin"));
        // 如果文件名不为空，则进行下载
        if (fileName != null) {
            //设置文件路径
            String realPath = "upload/excel/"; //服务器路径
            File file = new File(realPath, fileName);
            System.out.printf("下载 "+file.getAbsolutePath());
            // 如果文件名存在，则进行下载
            if (file.exists()) {
                // 配置文件下载
                response.setHeader("content-type", "application/octet-stream");
                response.setContentType("application/octet-stream");
                // 下载文件能正常显示中文
                response.setHeader("Content-Disposition", "attachment;filename=" + URLEncoder.encode(fileName, "UTF-8"));
                // 实现文件下载
                byte[] buffer = new byte[1024];
                FileInputStream fis = null;
                BufferedInputStream bis = null;
                try {
                    fis = new FileInputStream(file);
                    bis = new BufferedInputStream(fis);
                    OutputStream os = response.getOutputStream();
                    int i = bis.read(buffer);
                    while (i != -1) {
                        os.write(buffer, 0, i);
                        i = bis.read(buffer);
                    }
                    System.out.println("Download successfully!");
                }
                catch (Exception e) {
                    System.out.println("Download failed!");
                }
                finally {
                    if (bis != null) {
                        try {
                            bis.close();
                        } catch (IOException e) {
                            e.printStackTrace();
                        }
                    }
                    if (fis != null) {
                        try {
                            fis.close();
                        } catch (IOException e) {
                            e.printStackTrace();
                        }
                    }
                }
            }else {
                System.out.println("找不到文件");
            }
        }
    }

最后使用表单下载文件才没有出现这个情况