（本机）文件下载：都可一试（线上不行）

最新推荐文章于 2025-04-30 11:28:26 发布

你小子在干嘛

最新推荐文章于 2025-04-30 11:28:26 发布

阅读量91

点赞数

文章标签： java

本文链接：https://blog.youkuaiyun.com/jdaiwlsd/article/details/120473515

版权

HTTP响应文件下载用户代理编码处理文件流

关键词由优快云通过智能技术生成

/**
     * 下载/浏览器中打开文件
     *
     * @param id
     * @return
     * @throws Exception
     */
    @ResponseBody
    @GetMapping("downloadFile")
    @ApiOperation(value = "下载/浏览器中打开", notes = "")
    @ApiImplicitParams({
		@ApiImplicitParam(paramType = "query", dataType = "Long", name = "open", example = "0", value = "是否打开", required = true),
		@ApiImplicitParam(paramType = "query", dataType = "Long", name = "id", example = "0",value = "文件id", required = true) })
    public void downloadFile(HttpServletResponse response, HttpServletRequest request, Integer open, Long id) throws Exception {
        SmUploadFile fileInfo = uploadFileService.getUploadFileById(id);
        try {
            // path是指欲下载的文件的路径。
            File fileOnserver = new File(fileInfo.getFilePath());
            // 取得文件名。
            String filename = fileInfo.getFileName();
            // 取得文件的后缀名。
            String ext = null;
            if(fileInfo.getFilePath().lastIndexOf(".")>0){
                ext = fileInfo.getFilePath().substring(fileInfo.getFilePath().lastIndexOf("."));
            }
            if(ext!=null && filename.indexOf(ext)<0){
                filename = filename + ext;
            }

            String userAgent = request.getHeader("User-Agent");
            if(userAgent.toUpperCase().indexOf("TRIDENT") > 0) {
                filename = new String(filename.getBytes("GBK"), "ISO8859-1");
            } else if (userAgent.toUpperCase().indexOf("MSIE") > 0) {
                filename = URLEncoder.encode(filename, "UTF-8");
            } else {
                filename = new String(filename.getBytes("UTF-8"), "ISO8859-1");
            }

            // 以流的形式下载文件。
            InputStream fis = new BufferedInputStream(new FileInputStream(fileOnserver));
            byte[] buffer = new byte[fis.available()];
            fis.read(buffer);
            fis.close();
            // 清空response
            response.reset();
            // 设置response的Header
            response.addHeader("Content-Length", "" + fileOnserver.length());
            response.addHeader("Access-Control-Allow-Origin", "*");
            String contentType = fileInfo.getContentType();
            if(open!= null && open == 1 && contentType != null){
                response.setContentType(contentType);
            } else {
                response.setContentType("application/octet-stream");
                response.addHeader("Content-Disposition", "attachment;filename=" + filename);
            }
            OutputStream toClient = new BufferedOutputStream(response.getOutputStream());
            toClient.write(buffer);
            toClient.flush();
            toClient.close();
        } catch (IOException ex) {
            ex.printStackTrace();
        }
    }