Exception Report</p><p><b>Message</b> Request processing failed; nested exception is org.apache.ibatis.binding.BindingException: Invalid bound statement (not found): com.mmall.dao.UserMapper.checkUsername</p><p><b>Description</b> The server encountered an unexpected condition that prevented it from fulfilling the request.</p><p><b>Exception</b></p><pre>org.springframework.web.util.NestedServletException: Request processing failed; nested exception is org.apache.ibatis.binding.BindingException: Invalid bound statement (not found): com.mmall.dao.UserMapper.checkUsername
	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:661)
	org.springframework.web.servlet.FrameworkServlet.service(FrameworkServlet.java:807)
	javax.servlet.http.HttpServlet.service(HttpServlet.java:742)
	org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:52)
	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>org.apache.ibatis.binding.BindingException: Invalid bound statement (not found): com.mmall.dao.UserMapper.checkUsername
	org.apache.ibatis.binding.MapperMethod$SqlCommand.&lt;init&gt;(MapperMethod.java:223)
	org.apache.ibatis.binding.MapperMethod.&lt;init&gt;(MapperMethod.java:48)
	org.apache.ibatis.binding.MapperProxy.cachedMapperMethod(MapperProxy.java:59)
	org.apache.ibatis.binding.MapperProxy.invoke(MapperProxy.java:52)
	com.sun.proxy.$Proxy22.checkUsername(Unknown Source)
	com.mmall.service.impl.UserServiceImpl.login(UserServiceImpl.java:24)
	com.mmall.controller.portal.UserController.login(UserController.java:32)
	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:661)
	org.springframework.web.servlet.FrameworkServlet.service(FrameworkServlet.java:807)
	javax.servlet.http.HttpServlet.service(HttpServlet.java:742)
	org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:52)
	org.springframework.web.filter.CharacterEncodingFilter.doFilterInternal(CharacterEncodingFilter.java:88)