异常如下：

java.lang.IllegalStateException: No thread-bound request found: Are you referring to request attributes outside of an actual web request, or processing a request outside of the originally receiving thread? If you are actually operating within a web request and still receive this message, your code is probably running outside of DispatcherServlet/DispatcherPortlet: In this case, use RequestContextListener or RequestContextFilter to expose the current request. 

解决方案：

在web.xml中添加一个监听

  <listener><listener-class>org.springframework.web.context.request.RequestContextListener</listener-class></listener>
</web-app>