Grails Spring Security - 在会话超时后重新加载会话变量

I'm using spring security core in my grails application. My app has lots of ajax calls which call controllers. Controllers in turn, depend on some session variables to fulfil the request. I'm currently able to correctly display the ajax login form on session timeout. However, it creates a new session with only the newly created user object. All other objects stored in session are lost.I'm using spring security core in my grails app