前端访问的 controller 地址没有加方法名导致找不到。
Servlet.service() for servlet [spring] in context with path [/ssmDemo] threw exception [Request processing failed; nested exception is java.lang.IllegalStateException: Ambiguous handler methods mapped for HTTP path 'http://localhost:8080/user/': {public java.lang.String com.controller.InvitationController.toPageInvList(java.lang.Integer,com.vo.Page,javax.servlet.http.HttpServletRequest), public.....
解决方法：
请把地址复制出来，检查是否完整。
http://localhost:8080/user/list
