给下载添加登录过滤器

app/controllers/attachments_controller.rb

@@ -20,6 +20,8 @@ class AttachmentsController < ApplicationController
   before_filter :file_readable, :read_authorize, :only => [:show, :thumbnail]#Modified by young
   before_filter :delete_authorize, :only => :destroy
   before_filter :authorize_global, :only => :upload
+  
+  before_filter :require_login, only: [:download]
 
   accept_api_auth :show, :download, :upload