1.报错信息

严重: Servlet.service() for servlet [springmvc] in context with path [/om-waqs] threw exception [org.apache.shiro.session.InvalidSessionException: java.lang.IllegalStateException: getAttribute: Session already invalidated] with root cause
java.lang.IllegalStateException: getAttribute: Session already invalidated
	at org.apache.catalina.session.StandardSession.getAttribute(StandardSession.java:1189)
	at org.apache.catalina.session.StandardSessionFacade.getAttribute(StandardSessionFacade.java:120)
	at org.apache.shiro.web.session.HttpServletSession.getAttribute(HttpServletSession.java:146)
	at org.apache.shiro.session.ProxiedSession.getAttribute(ProxiedSession.java:121)
	at org.apache.shiro.subject.support.DelegatingSubject.getRunAsPrincipalsStack(DelegatingSubject.java:469)
	at org.apache.shiro.subject.support.DelegatingSubject.getPrincipals(DelegatingSubject.java:153)
	at org.apache.shiro.subject.support.DelegatingSubject.getPrincipal(DelegatingSubject.java:149)
	at org.apache.shiro.web.servlet.ShiroHttpServletRequest.getSubjectPrincipal(ShiroHttpServletRequest.java:96)
	at org.apache.shiro.web.servlet.ShiroHttpServletRequest.getUserPrincipal(ShiroHttpServletRequest.java:112)
	at javax.servlet.http.HttpServletRequestWrapper.getUserPrincipal(HttpServletRequestWrapper.java:184)
	at javax.servlet.http.HttpServletRequestWrapper.getUserPrincipal(HttpServletRequestWrapper.java:184)
	at org.springframework.web.servlet.FrameworkServlet.getUsernameForRequest(FrameworkServlet.java:1069)
	at org.springframework.web.servlet.FrameworkServlet.publishRequestHandledEvent(FrameworkServlet.java:1051)
	at org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:986)
	at org.springframework.web.servlet.FrameworkServlet.doPost(FrameworkServlet.java:853)
	at javax.servlet.http.HttpServlet.service(HttpServlet.java:646)
	at org.springframework.web.servlet.FrameworkServlet.service(FrameworkServlet.java:827)
	at javax.servlet.http.HttpServlet.service(HttpServlet.java:727)
	at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:303)
	at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:208)
	at org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:52)
	at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:241)
	at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:208)
	at com.yhb.vortex.filter.XssFilter.doFilter(XssFilter.java:88)
	at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:241)
	at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:208)
	at org.apache.shiro.web.servlet.ProxiedFilterChain.doFilter(ProxiedFilterChain.java:61)
	at org.apache.shiro.web.servlet.AdviceFilter.executeChain(AdviceFilter.java:108)
	at org.apache.shiro.web.servlet.AdviceFilter.doFilterInternal(AdviceFilter.java:137)
	at org.apache.shiro.web.servlet.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:125)
	at org.apache.shiro.web.servlet.ProxiedFilterChain.doFilter(ProxiedFilterChain.java:66)
	at org.apache.shiro.web.servlet.AbstractShiroFilter.executeChain(AbstractShiroFilter.java:449)
	at org.apache.shiro.web.servlet.AbstractShiroFilter$1.call(AbstractShiroFilter.java:365)
	at org.apache.shiro.subject.support.SubjectCallable.doCall(SubjectCallable.java:90)
	at org.apache.shiro.subject.support.SubjectCallable.call(SubjectCallable.java:83)
	at org.apache.shiro.subject.support.DelegatingSubject.execute(DelegatingSubject.java:383)
	at org.apache.shiro.web.servlet.AbstractShiroFilter.doFilterInternal(AbstractShiroFilter.java:362)
	at org.apache.shiro.web.servlet.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:125)
	at org.springframework.web.filter.DelegatingFilterProxy.invokeDelegate(DelegatingFilterProxy.java:343)
	at org.springframework.web.filter.DelegatingFilterProxy.doFilter(DelegatingFilterProxy.java:260)
	at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:241)
	at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:208)
	at org.springframework.web.filter.CharacterEncodingFilter.doFilterInternal(CharacterEncodingFilter.java:88)
	at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:106)
	at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:241)
	at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:208)
	at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:220)
	at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:122)
	at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:501)
	at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:171)
	at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:103)
	at org.apache.catalina.valves.AccessLogValve.invoke(AccessLogValve.java:950)
	at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:116)
	at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:408)
	at org.apache.coyote.http11.AbstractHttp11Processor.process(AbstractHttp11Processor.java:1070)
	at org.apache.coyote.AbstractProtocol$AbstractConnectionHandler.process(AbstractProtocol.java:611)
	at org.apache.tomcat.util.net.JIoEndpoint$SocketProcessor.run(JIoEndpoint.java:316)
	at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1149)
	at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624)
	at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61)
	at java.lang.Thread.run(Thread.java:748)

2.解决思路

我先在百度上找了找解决方案，说是网络异常导致长时间连不上数据库，无法获取到数据，导致session超时。

3.报错原因

很明显，百度上写的跟我的报错原因不一致，通过debug后台代码，发现是没有做实体类为空的校验，导致在获取对应值时报null，在controller层只catch了IOException异常，所以，导致了以上问题的产生。

4.解决方案

添加了对实体类为空的校验。