springboot 中文件上传下载实例代码

@Controllerpublic class FileUploadCtrl { @Value("${file.upload.dir}") private String path; /**  * 实现文件上传  * */ @RequestMapping(value = "/fileUpload", method = RequestMethod.POST) @ResponseBody public Map<String,Object> fileUpload(@RequestParam("fileName") MultipartFile file){  Map<String,Object> map = new HashMap<String, Object>();  int no = 0;  String msg = "上传失败！";  if(!file.isEmpty()){   String fileName = file.getOriginalFilename();   File dest = new File(path + "/" + fileName);   if(!dest.getParentFile().exists()){ //判断文件父目录是否存在    dest.getParentFile().mkdir();   }   try {    file.transferTo(dest); //保存文件    no = 1;    msg = "上传成功！";   } catch (IllegalStateException e) {    e.printStackTrace();   } catch (IOException e) {    e.printStackTrace();   }  }  map.put("no",no);  map.put("msg", msg);  return map; } @RequestMapping(   value = "/fileDownload",   method = RequestMethod.GET ) public ResponseEntity<?> getGwFileContent(@RequestParam String fileName,@RequestParam int flag) {  HttpHeaders headers = new HttpHeaders();  headers.add("Cache-Control", "no-cache, no-store, must-revalidate");  String filepath = path+"/"+fileName;;  InputStream is = null;  try {   headers.add("Content-Disposition", String.format("attachment; filename=/"%s/"", new String(fileName.getBytes("GBK"), "ISO8859-1")));   if(flag==0){//表示获取缩略图    File file = new File(filepath);    filepath = path+"/xx"+fileName;    File xxFile = new File(filepath);    if(!xxFile.exists()){//不存在就生成缩略图     Thumbnails.of(file).scale(0.25f).toFile(xxFile);    }   }   is = new FileInputStream(new File(filepath));  } catch (UnsupportedEncodingException e) {   e.printStackTrace();  } catch (FileNotFoundException e) {   e.printStackTrace();  } catch (IOException e) {   e.printStackTrace();  }  headers.add("Pragma", "no-cache");  headers.add("Expires", "0");  return ResponseEntity    .ok()    .headers(headers)    .contentType(MediaType.parseMediaType("application/octet-stream"))    .body(new InputStreamResource(is)); }}