服务器文件上传下载删除

最新推荐文章于 2021-08-09 18:13:42 发布

HezhezhiyuLe

最新推荐文章于 2021-08-09 18:13:42 发布

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CC 4.0 BY-SA版权

分类专栏：后端文章标签：文件上传下载删除 IO流

本文链接：https://blog.youkuaiyun.com/HezhezhiyuLe/article/details/90270061

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本文详细介绍了一个项目中实现文件上传、下载及删除功能的具体代码实现。包括如何使用MultipartFile处理文件上传，如何通过HTTP响应实现文件下载，以及如何安全地删除服务器上的文件。文章还提供了异常处理和文件流关闭的注意事项。

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前言

最近一个项目使用到了文件下载，写篇博客记录
basePath为父目录路径(?)

上传

 /**
     * 文件上传
     * @param files
     * @return
     */
    @PostMapping(value = "/uploadFile")
    public ReturnMsg upload(@RequestParam(value = "file", required = false) MultipartFile[] files){
        if (files == null || files.length == 0)
            return new ReturnMsg("200","操作成功",null);
        StringBuilder fileName = new StringBuilder();
        List<String> returnFileNames = new ArrayList<>(); //返回给前端已经上传成功的文件集合
        Map<String,String> map=new HashMap<>();
        for (MultipartFile file: files) {
            if(file.isEmpty())
                continue;
            String originalFilename = file.getOriginalFilename(); //上传文件名
            int i = originalFilename.lastIndexOf(".");

            String serverFileName = System.currentTimeMillis()+"_"+originalFilename; //存储到服务器中的文件名
            fileName.append(serverFileName).append(","); //储存到数据库文件名拼接串
            //filePath.append(basePath).append(serverFileName).append(","); //存储到数据库文件路径拼接串
            try {
                File file1 = new File(basePath);
                if (!file1.exists())
                    file1.mkdirs();
                Path path = Paths.get(basePath, serverFileName);
                Files.copy(file.getInputStream(),path);
            } catch (IOException e) {
                e.printStackTrace();
                return new ReturnMsg("400","文件上传失败，请重试");
            }
            returnFileNames.add(serverFileName); //将成功上传的文件名添加到list中
            map.put("fileName",originalFilename);
            map.put("filePath",serverFileName);
        }
        return new ReturnMsg("200","上传成功",map);
    }

下载

 /**
     * 文件下载
     * @param fileName
     * @param response
     * @return
     */
    @GetMapping(value = "/file/{fileName:.+}")
    public ReturnMsg downLoadFile(@PathVariable String fileName, HttpServletResponse response){
        if (ValidUtil.checkStr(fileName))
            return new ReturnMsg("400","请指定需要下载的文件");
        File file = new File(basePath, fileName);
        //System.out.println(file.getPath());
        if(!file.exists()||file.isDirectory())
            return new ReturnMsg("400","文件不存在");
        response.setHeader("Content-Disposition","attachment;filename"+fileName);
        //response.setContentType("application/octet-stream");
        FileInputStream fileInputStream = null;
        BufferedInputStream bufferedInputStream = null;
        ServletOutputStream outputStream = null;
        byte[]buffer = new byte[1024];
        try {
            fileInputStream = new FileInputStream(file);
            bufferedInputStream = new BufferedInputStream(fileInputStream);
            outputStream = response.getOutputStream();
            int read = bufferedInputStream.read(buffer);
            while (read!=-1){
                outputStream.write(buffer,0,read);
                read = bufferedInputStream.read(buffer);
            }
            outputStream.flush();
            outputStream.close();
        } catch (IOException e) {
            return new ReturnMsg("400","文件下载失败");
        }finally {
            if(bufferedInputStream!=null){
                try {
                    bufferedInputStream.close();
                } catch (IOException e) {
                    System.out.println("文件流关闭失败");
                }
            }
            if(fileInputStream!=null){
                try {
                    fileInputStream.close();
                } catch (IOException e) {
                    System.out.println("文件流关闭失败");
                }
            }
        }
        return new ReturnMsg("200","文件下载成功");
    }

删除

   /**
     * 文件删除
     * @param filePath
     * @throws MyException
     */
    @GetMapping("/deleteFile")
    public ReturnMsg deleteFile(String filePath) throws MyException {
        File file = new File(basePath,filePath);
        System.out.println(file.getPath());
        System.out.println(file.exists());
        if(!file.exists()||file.isDirectory()){
           // throw new MyException("该文件不存在");
            return new ReturnMsg("400",filePath+",该文件不存在");
        }
        try{
            //deleteOnExit删除不太好使换成下边的
            //file.deleteOnExit();
            file.delete();
        }catch (Exception e){
            throw new RuntimeException("删除失败"+e);
        }
        return new ReturnMsg("200","删除成功");
    }