org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:943) org.springframework.web.servlet.FrameworkServlet.doPost(FrameworkServlet.java:833) javax.servlet.http.HttpServlet.service(HttpServlet.java:660) org.springframework.web.servlet.FrameworkServlet.service(FrameworkServlet.java:807) javax.servlet.http.HttpServlet.service(HttpServlet.java:741) org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:53) org.springframework.web.filter.CharacterEncodingFilter.doFilterInternal(CharacterEncodingFilter.java:88) org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:108)</pre><p><b>Root Cause</b></p><pre>java.lang.ClassCastException: com.mmall.common.ServerResponse cannot be cast to com.mmall.pojo.User com.mmall.controller.UserController.getUserInfo(UserController.java:58) sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62) sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) java.lang.reflect.Method.invoke(Method.java:498) org.springframework.web.method.support.InvocableHandlerMethod.invoke(InvocableHandlerMethod.java:214) org.springframework.web.method.support.InvocableHandlerMethod.invokeForRequest(InvocableHandlerMethod.java:132) org.springframework.web.servlet.mvc.method.annotation.ServletInvocableHandlerMethod.invokeAndHandle(ServletInvocableHandlerMethod.java:104) org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.invokeHandleMethod(RequestMappingHandlerAdapter.java:748) org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.handleInternal(RequestMappingHandlerAdapter.java:689) org.springframework.web.servlet.mvc.method.AbstractHandlerMethodAdapter.handle(AbstractHandlerMethodAdapter.java:83) org.springframework.web.servlet.DispatcherServlet.doDispatch(DispatcherServlet.java:945) org.springframework.web.servlet.DispatcherServlet.doService(DispatcherServlet.java:876) org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:931) org.springframework.web.servlet.FrameworkServlet.doPost(FrameworkServlet.java:833) javax.servlet.http.HttpServlet.service(HttpServlet.java:660) org.springframework.web.servlet.FrameworkServlet.service(FrameworkServlet.java:807) javax.servlet.http.HttpServlet.service(HttpServlet.java:741) org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:53) org.springframework.web.filter.CharacterEncodingFilter.doFilterInternal(CharacterEncodingFilter.java:88) org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:108)</pre><p><b>Note</b> The full stack trace of the root cause is available in the server logs.</p><hr class="line" ><h3>Apache Tomcat/9.0.2</h3></body></html>