java 上传图片

	//application.yml中配置path和prefix
	//上传图片的地址
    @Value(value = "${uploadfilepath}")
    private  String uploadFilePath;
    //图片的前缀eg:http:127.0.0.1:8080/manage_image
    @Value(value = "${imageUrlPrefix}")
    private  String imageUrlPrefix;
    @PostMapping(value = "/addPic")
    public ReturnWrapper<String> upload(@RequestParam("file") MultipartFile imgFile) {
        if (imgFile.isEmpty()) {
            return ReturnWrapMapper.ok("文件不能为空");
        }
        //原始文件名
        String originalFilename = imgFile.getOriginalFilename();
        //计算后缀有几位 .jpg
        int i = imgFile.getOriginalFilename().lastIndexOf(".");
        //截取后四位是文件的格式
        String substring = originalFilename.substring(i);
        //生成文件唯一标识名称
        String filename = UniqueID.nextId(substring);
        try {
            File newFile = new File(uploadFilePath + filename);
            imgFile.transferTo(newFile);
        } catch (IOException e) {
            return ReturnWrapMapper.error(ReturnCode.FILE_UPLOAD_ERROR);
        }
        //上传的位置http:127.0.0.1:8080/manage_image/123.jpg
        String imgUrl = imageUrlPrefix + filename;
        return ReturnWrapMapper.ok(imgUrl);
    }
}