[系统运维]实现上传文件到服务器上

前言：
我使用nginx 在阿里云服务器上搭建了静态资源文件服务器。

下面是实现上传的代码。
uploadController

  @CrossOrigin
    @PostMapping(value = "upload")
    public RespBean upload(@RequestParam("file") MultipartFile file,Integer sid , Integer aid ,String uid) {
        if (file.isEmpty()) {
            return new RespBean(400, "请选择文件", null);
        }
        String fileName = file.getOriginalFilename();
        String [] fileSuffix = file.getContentType().split("/");

        ByteArrayOutputStream outputStream = new ByteArrayOutputStream();
        String key;
        //如果是图片则上传到七牛云并形成外链
        if (PictureType.isInclude(fileSuffix[1])) {
            byte[] uploadBytes;
            Map<String, String> map = new HashMap<>();
            //如果文件大小超过5M进行压缩
            if (file.getSize() >= 5 * 1024 * 1024) {
                try {
                    Thumbnails.of(file.getInputStream())
                            .scale(1f)
                            .outputQuality(0.5f)
                            .outputFormat("jpg")
                            .toOutputStream(outputStream);
                    uploadBytes = outputStream.toByteArray();
                    fileName = SHA.SHA256(outputStream);
                    map = QiNiuPicture.upload(fileName, uploadBytes);
                } catch (IOException | NoSuchAlgorithmException e) {
                    e.printStackTrace();
                    System.out.println("图片压缩失败");
                }
            } else {
                try {
                    uploadBytes = file.getBytes();
                    outputStream.write(uploadBytes);
                    fileName = SHA.SHA256(outputStream);
                    map = QiNiuPicture.upload(fileName, uploadBytes);
                } catch (IOException | NoSuchAlgorithmException e) {
                    e.printStackTrace();
                }
            }
            if (map.containsKey("key")) {
                key = map.get("key");
                String outerChain = QiNiuPicture.outerChainBuild(key);
                if (outerChain == null) {
                    return easyRespBean.err();
                }
                return easyRespBean.ok(outerChain);
            }
        } else {
            //非图片文件本地保存
            String url = baseUrl + uid+"/"+fileSuffix[0]+"/" + fileName ;

            try {
                createDir(uid+"/"+fileSuffix[0]);
                File dest = new File(filePath+ uid+"/"+fileSuffix[0] +"/"+ fileName);
                file.transferTo(dest);
                int result = fileService.upLoadFile(fileName,url,fileSuffix[0],uid,aid,sid);
                if(result == 0)
                    return easyRespBean.ok(url);
                else
                    return easyRespBean.errWithMsg("上传失败");
            } catch (IOException e) {
                e.printStackTrace();
                return easyRespBean.errWithMsg("上传失败");
            }
        }

        return easyRespBean.errWithMsg("上传失败");
    }

这可以实现在nginx配置的根目录，按照文件类型放置上传的文件。