进击的java(5) spring mvc 文件上传下载

最新推荐文章于 2025-08-10 23:51:42 发布

weixin_33966095

最新推荐文章于 2025-08-10 23:51:42 发布

阅读量61

点赞数

CC 4.0 BY-SA版权

文章标签：测试 java python

原文链接：https://my.oschina.net/SearchVera/blog/468861

本文详细介绍了使用Spring MVC进行文件上传与下载的操作，包括控制器、服务层和前端实现，涉及MultipartFile、HttpServletResponse等关键组件的应用。

摘要生成于 C知道，由 DeepSeek-R1 满血版支持，前往体验 >

2019独角兽企业重金招聘Python工程师标准>>>

###spring mvc 文件上传下载

####上传

用MultipartFile来上传文件，上传到本地指定路径下

controller:

  @RequestMapping(value = "/upload")
  @ResponseBody
  public String upload(@RequestParam("file") MultipartFile file,
  	@RequestParam("type") Integer type, HttpServletRequest request,
  	HttpServletResponse response) {

  	Preconditions.checkNotNull(type);
  	Preconditions.checkNotNull(file);
  	Preconditions.checkArgument(file.getSize() < Constants.FILE_MAX_SIZE);
  	Preconditions.checkArgument(Constants.FILE_TYPE_MAP.containsKey(type));

  	if (!this.validate(file)) {
  		return JsonReply.newItem().failed().toJson();
  	}

  	String path = request.getSession().getServletContext().getRealPath("/");

  	Long fileId = fileService.saveFile(file, type, path);

  	if (fileId.equals(Constants.ERROR_LONG)) {
  		return JsonReply.newItem().failed().toJson();
  	}

  	JsonReply reply = JsonReply.newItem();
  	reply.addObject("id", fileId);
  	return reply.success().toJson();

  }

type是对类型做一个分类，不同类别放到不同文件夹下

service:

  @Override
  public Long saveFile(@NonNull MultipartFile multipartFile, Integer type,
  	String path) {
  	// TODO Auto-generated method stub
  	String originalName = multipartFile.getOriginalFilename();

  	// String fileDir = path + originalName;
  	String fileDir = Constants.FILE_DIR + Constants.FILE_TYPE_MAP.get(type)
  			+ originalName;

  	final File file = new File(fileDir);
  	try {
  		Files.write(multipartFile.getBytes(), file);
  	} catch (IOException e) {
  		// TODO: handle exception
  		log.info("save file error,{}", e);
  		return Constants.ERROR_LONG;
  	}

  	FileBo fileBo = new FileBo();
  	fileBo.setUrl(originalName);
  	fileBo.setType(type);
  	fileDao.saveFileInfo(fileBo);
  	return fileBo.getId();

}

前端：

  <body>
  <form id="form" method="post" action="./dundun-web/file/upload" enctype="multipart/form-data">                  
  <tr>  
      <td width="25%" align="right">上传文件：</td>  
      <td><input id="file" type="file" NAME="file" style="width:300px;"></td>  
  </tr>  
  <tr>
  	<label for="type" class="sr-only">类别</label>
      <input type="text" id="type" name="type" class="form-control" placeholder="类别" style="width:300px;">
  </tr>
  <br>
  <tr align="center" valign="middle">  
      <td height="60" colspan="2"><input type="submit" ID="BtnOK" value="确认上传"></td>  
  </tr>  
  </form>  

  <!-- Bootstrap core JavaScript
  ================================================== -->
  <!-- Placed at the end of the document so the pages load faster -->
  <script src="http://cdn.bootcss.com/jquery/1.11.2/jquery.min.js"></script>
  <script src="http://cdn.bootcss.com/bootstrap/3.3.4/js/bootstrap.min.js"></script>
  </body>

#####下载

用HttpServletResponse来下载，但是不是最好的选择，今后改

controller:

  @RequestMapping(value = "/download/{id}")
  public void file(@PathVariable Long id, HttpServletResponse resp)
  	throws IOException {

  	OutputStream output = resp.getOutputStream();

  	Preconditions.checkNotNull(id);

  	FileBo file = fileService.getFileBo(id);
  	if (file == null) {
  		return;
  	}
  	String disposition = "attachment;filename=" + file.getUrl();
  	resp.reset();
  	resp.setHeader("Content-Disposition", disposition);
  	resp.setContentType("application/octet-stream; charset=utf-8");

  	try {
  		fileService.download(file, output);
  	} catch (IOException e) {
  		// TODO: handle exception
  		log.info("FileController.file failed.[{e}]", e);
  	} finally {
  		IOUtils.closeQuietly(output);
  	}
  }

service

  @Override
  public void download(FileBo file, OutputStream output) throws IOException {
  	// TODO Auto-generated method stub

  	String fileDir = Constants.FILE_DIR
  			+ Constants.FILE_TYPE_MAP.get(file.getType()) + file.getUrl();

  	final File downloadFile = new File(fileDir);

  	output.write(FileUtils.readFileToByteArray(downloadFile));

  }

转载于:https://my.oschina.net/SearchVera/blog/468861