重写 Uploader 的 filename

def filename
 "#{secure_token}.#{file.extension}" if original_filename.present?
end

uploader 文件

def store_dir
    #"uploads/#{model.class.to_s.underscore}/#{mounted_as}/#{model.id}"
    "#{Rails.root}/../dfs/"
end

def extension_white_list
     %w(jpg jpeg gif png) 
end

def filename
    if original_filename
      uuid = UUIDTools::UUID.random_create.to_s
      uuid_p = uuid.gsub('-','')
      @name = file.extension+"/"+uuid_p[1,2]+"/"+uuid_p[4,2]+"/"+uuid_p[7,2]+"/"+uuid_p[10,22]+"."+file.extension
      # current_path 是 Carrierwave 上传过程临时创建的一个文件，有时间标记，所以它将是唯一的
      "#{@name}"
    end
  end