上传文件

• 上传文件
  • 请求：必须是POST请求
  • 表单：enctype=“multipart/form-data”
  • Spring MVC：通过 MultipartFile 处理上传文件
• 开发步骤
  • 访问账号设置页面
  • 上传头像
  • 获取头像

开发步骤

①访问账号设置页面

前端部分，已写好.html文件

②上传头像

MultipartFile 用于接受前端传回的图片

@RequestMapping(path = "/upload",method = RequestMethod.POST)
    public String uploadHeader(MultipartFile headerImage, Model model){
        if(headerImage == null){
            model.addAttribute("error","您还没有选择图片！");
            return "/site/setting";
        }
        String fileName = headerImage.getOriginalFilename();
        String suffix = fileName.substring(fileName.lastIndexOf("."));
        if(StringUtils.isBlank(suffix)){
            model.addAttribute("error","文件格式不正确");
            return "/site/setting";
        }
        //生成随机文件名
        fileName = CommunityUtil.generateUUID() + suffix;
        //确定文件的存放路径
        File dest = new File(uploadPath + "/" +fileName);
        try {
            //存储文件
            headerImage.transferTo(dest);
        } catch (IOException e) {
            logger.error("上传文件失败" + e.getMessage());
            throw new RuntimeException("上传文件失败，服务器发生异常！",e);
        }
        //更新当前用户的头像的网址
        User user = hostHolder.getUser();
        String headerUrl = domain + contextPath +"/user/header/" + fileName;
        userService.updateHeader(user.getId(),headerUrl);
        return "redirect:/index";
    }

程序当中用到了updateHeader()方法，以此需在服务层添加该方法

public int updateHeader(int userId,String headerUrl){
    return userMapper.updateHeader(userId,headerUrl);
}

③获取头像

@RequestMapping(path = "/header/{fileName}",method = RequestMethod.GET)
    public void getHeader(@PathVariable("fileName") String fileName, HttpServletResponse response){
        //服务器存放路径
        fileName = uploadPath + "/" + fileName;
        //文件后缀
        String suffix = fileName.substring(fileName.lastIndexOf("."));
        response.setContentType("image/" + suffix);
        try (
                FileInputStream fis = new FileInputStream(fileName);
                OutputStream os = response.getOutputStream();
            ){
                 byte[] buffer = new byte[1024];
                 int b = 0;
                 while((b = fis.read(buffer)) != -1){
                     os.write(buffer,0, b);
                 }
        }  catch (IOException e) {
            logger.error("读取头像失败" + e.getMessage());
        }
    }

④图片过大异常处理

Spirngboot默认最大上传10m，如果过大就会异常，前期用这个异常控制器处理，后期更新更好的方法

  @ExceptionHandler(value = MultipartException.class)
    @ResponseBody
    public ModelAndView handleBusinessException(MaxUploadSizeExceededException ex) {
        String msg;
        if (ex.getCause().getCause() instanceof FileSizeLimitExceededException) {
            log.error(ex.getMessage());
            msg = "上传文件过大[单文件大小不得超过10M]";
        } else if (ex.getCause().getCause() instanceof SizeLimitExceededException) {
            log.error(ex.getMessage());
            msg = "上传文件过大[总上传文件大小不得超过10M]";
        } else {
            msg = "上传文件失败";
        }
        ModelAndView modelAndView = new ModelAndView();
        modelAndView.setViewName("/site/setting");
        modelAndView.addObject("error","文件过大");
        return modelAndView;
    }

再配置好相关的.html文件即可进行测试

标签：文件,仿牛,String,账号,fileName,客网,error,return,上传
来源： https://www.cnblogs.com/nevererror/p/16210311.html