public R upload(
            @RequestParam(value = "file") MultipartFile file,
            @RequestParam(value = "isSingle", required = false, defaultValue = "false") Boolean isSingle,
            @RequestParam(value = "id", required = false) Long id,
            @RequestParam(value = "bizId", required = false) String bizId,
            @RequestParam(value = "bizType", required = false) String bizType) {
                //...
            }