序
獲取外部上下文: FacesContext.getCurrentInstance().getExternalContext()
一.獲取 ServletContext, ServletRequest, ServletResponse
public abstract Object getContext()
public abstract Object getRequest()
public abstract Object getResponse()
二.獲取 Session
HttpServletRequest 接口的getSession()
public abstract Object getSession(boolean create): 當前用戶沒有相應的session對象,true->創建; false->返回null.