Action中的成员变量是否线程安全

一直以来一直存在这样的疑问，作为成员变量，Action中的dao是否存在线程安全的问题，多线程同时访问是否存在安全性问题呢，path是否也存在线程安全问题呢

public class UserManagerAction extends Action {
         private UserDAO dao ＝ new UserDAO();           
         private String path = "";
	@Override
	public ActionForward execute(ActionMapping mapping, ActionForm form,
			HttpServletRequest request, HttpServletResponse response)
			throws Exception {
		path = request.getParameter("path");
		String forward = "success";
		if("add".equals(path)){
		   //业务代码....
		}
		
		return mapping.findForward(forward);
	}

}