import org.springframework.http.MediaType;

@GetMapping(value = "/file/image/{id}", produces = {MediaType.IMAGE_JPEG_VALUE, MediaType.IMAGE_PNG_VALUE})
@ResponseBody
public byte[] image(@PathVariable String id){
    byte[] data = null;
    UploadFile file = mongoTemplate.findImageById(id, UploadFile.class);
    if(file != null){
        data = file.getContent().getData();
    }
    return data;
}