NullPointerException during logout

[tk0no]

We have large MPR project and we noticed that if user does logout by url (types specific logout url fragment to browser) in Chrome, every thing goes fine on UI, but there is error on the log (see below). In firefox error is not shown.

Logout code like this:

UI.getCurrent().getPage().setLocation("/app/index.html");
VaadinSession.getCurrent().getSession().invalidate(); 

It’s called in route afterNavigation(AfterNavigationEvent event) method.

• Versions:
  • Vaadin Framework 8.20.3
  • Flow 22.1.2
  • MPR 5.1.4
  • Java JRE / JDK 8
  • Browser Chrome

Exception handling request to /T360/framework: javax.servlet.ServletException: com.vaadin.server.ServiceException: java.lang.NullPointerException
	at com.vaadin.server.VaadinServlet.service(VaadinServlet.java:459)
	at javax.servlet.http.HttpServlet.service(HttpServlet.java:590)
	at io.undertow.servlet.handlers.ServletHandler.handleRequest(ServletHandler.java:74)
	at io.undertow.servlet.handlers.FilterHandler$FilterChainImpl.doFilter(FilterHandler.java:129)
	at io.undertow.websockets.jsr.JsrWebSocketFilter.doFilter(JsrWebSocketFilter.java:173)
	at io.undertow.servlet.core.ManagedFilter.doFilter(ManagedFilter.java:61)
	at io.undertow.servlet.handlers.FilterHandler$FilterChainImpl.doFilter(FilterHandler.java:131)
	at io.opentracing.contrib.jaxrs2.server.SpanFinishingFilter.doFilter(SpanFinishingFilter.java:52)
	at io.undertow.servlet.core.ManagedFilter.doFilter(ManagedFilter.java:61)
	at io.undertow.servlet.handlers.FilterHandler$FilterChainImpl.doFilter(FilterHandler.java:131)
	at io.undertow.servlet.handlers.FilterHandler.handleRequest(FilterHandler.java:84)
	at io.undertow.servlet.handlers.security.ServletSecurityRoleHandler.handleRequest(ServletSecurityRoleHandler.java:62)
	at io.undertow.servlet.handlers.ServletChain$1.handleRequest(ServletChain.java:68)
	at io.undertow.servlet.handlers.ServletDispatchingHandler.handleRequest(ServletDispatchingHandler.java:36)
	at org.wildfly.extension.undertow.security.SecurityContextAssociationHandler.handleRequest(SecurityContextAssociationHandler.java:78)
	at io.undertow.server.handlers.PredicateHandler.handleRequest(PredicateHandler.java:43)
	at io.undertow.servlet.handlers.RedirectDirHandler.handleRequest(RedirectDirHandler.java:68)
	at io.undertow.servlet.handlers.security.SSLInformationAssociationHandler.handleRequest(SSLInformationAssociationHandler.java:132)
	at io.undertow.servlet.handlers.security.ServletAuthenticationCallHandler.handleRequest(ServletAuthenticationCallHandler.java:57)
	at io.undertow.server.handlers.PredicateHandler.handleRequest(PredicateHandler.java:43)
	at io.undertow.security.handlers.AuthenticationConstraintHandler.handleRequest(AuthenticationConstraintHandler.java:53)
	at io.undertow.security.handlers.AbstractConfidentialityHandler.handleRequest(AbstractConfidentialityHandler.java:46)
	at io.undertow.servlet.handlers.security.ServletConfidentialityConstraintHandler.handleRequest(ServletConfidentialityConstraintHandler.java:64)
	at io.undertow.servlet.handlers.security.ServletSecurityConstraintHandler.handleRequest(ServletSecurityConstraintHandler.java:59)
	at io.undertow.security.handlers.AuthenticationMechanismsHandler.handleRequest(AuthenticationMechanismsHandler.java:60)
	at io.undertow.servlet.handlers.security.CachedAuthenticatedSessionHandler.handleRequest(CachedAuthenticatedSessionHandler.java:77)
	at io.undertow.security.handlers.NotificationReceiverHandler.handleRequest(NotificationReceiverHandler.java:50)
	at io.undertow.security.handlers.AbstractSecurityContextAssociationHandler.handleRequest(AbstractSecurityContextAssociationHandler.java:43)
	at io.undertow.server.handlers.PredicateHandler.handleRequest(PredicateHandler.java:43)
	at org.wildfly.extension.undertow.security.jacc.JACCContextIdHandler.handleRequest(JACCContextIdHandler.java:61)
	at io.undertow.server.handlers.PredicateHandler.handleRequest(PredicateHandler.java:43)
	at org.wildfly.extension.undertow.deployment.GlobalRequestControllerHandler.handleRequest(GlobalRequestControllerHandler.java:68)
	at io.undertow.server.handlers.PredicateHandler.handleRequest(PredicateHandler.java:43)
	at io.undertow.servlet.handlers.ServletInitialHandler.handleFirstRequest(ServletInitialHandler.java:269)
	at io.undertow.servlet.handlers.ServletInitialHandler.access$100(ServletInitialHandler.java:78)
	at io.undertow.servlet.handlers.ServletInitialHandler$2.call(ServletInitialHandler.java:133)
	at io.undertow.servlet.handlers.ServletInitialHandler$2.call(ServletInitialHandler.java:130)
	at io.undertow.servlet.core.ServletRequestContextThreadSetupAction$1.call(ServletRequestContextThreadSetupAction.java:48)
	at io.undertow.servlet.core.ContextClassLoaderSetupAction$1.call(ContextClassLoaderSetupAction.java:43)
	at org.wildfly.extension.undertow.security.SecurityContextThreadSetupAction.lambda$create$0(SecurityContextThreadSetupAction.java:105)
	at org.wildfly.extension.undertow.deployment.UndertowDeploymentInfoService$UndertowThreadSetupAction.lambda$create$0(UndertowDeploymentInfoService.java:1504)
	at org.wildfly.extension.undertow.deployment.UndertowDeploymentInfoService$UndertowThreadSetupAction.lambda$create$0(UndertowDeploymentInfoService.java:1504)
	at org.wildfly.extension.undertow.deployment.UndertowDeploymentInfoService$UndertowThreadSetupAction.lambda$create$0(UndertowDeploymentInfoService.java:1504)
	at org.wildfly.extension.undertow.deployment.UndertowDeploymentInfoService$UndertowThreadSetupAction.lambda$create$0(UndertowDeploymentInfoService.java:1504)
	at io.undertow.servlet.handlers.ServletInitialHandler.dispatchRequest(ServletInitialHandler.java:249)
	at io.undertow.servlet.handlers.ServletInitialHandler.access$000(ServletInitialHandler.java:78)
	at io.undertow.servlet.handlers.ServletInitialHandler$1.handleRequest(ServletInitialHandler.java:99)
	at io.undertow.server.Connectors.executeRootHandler(Connectors.java:376)
	at io.undertow.server.HttpServerExchange$1.run(HttpServerExchange.java:830)
	at org.jboss.threads.ContextClassLoaderSavingRunnable.run(ContextClassLoaderSavingRunnable.java:35)
	at org.jboss.threads.EnhancedQueueExecutor.safeRun(EnhancedQueueExecutor.java:1982)
	at org.jboss.threads.EnhancedQueueExecutor$ThreadBody.doRunTask(EnhancedQueueExecutor.java:1486)
	at org.jboss.threads.EnhancedQueueExecutor$ThreadBody.run(EnhancedQueueExecutor.java:1377)
	at java.lang.Thread.run(Thread.java:750)
Caused by: com.vaadin.server.ServiceException: java.lang.NullPointerException
	at com.vaadin.server.VaadinService.handleExceptionDuringRequest(VaadinService.java:1711)
	at com.vaadin.server.VaadinService.handleRequest(VaadinService.java:1671)
	at com.vaadin.server.VaadinServlet.service(VaadinServlet.java:457)
	... 53 more
Caused by: java.lang.NullPointerException
	at java.util.Objects.requireNonNull(Objects.java:203)
	at com.vaadin.mpr.core.MprSession.<init>(MprSession.java:40)
	at com.vaadin.mpr.core.MprServletService.createVaadinSession(MprServletService.java:186)
	at com.vaadin.server.VaadinService.createAndRegisterSession(VaadinService.java:849)
	at com.vaadin.server.VaadinService.doFindOrCreateVaadinSession(VaadinService.java:818)
	at com.vaadin.server.VaadinService.findOrCreateVaadinSession(VaadinService.java:758)
	at com.vaadin.server.VaadinService.findVaadinSession(VaadinService.java:596)
	at com.vaadin.server.VaadinService.handleRequest(VaadinService.java:1653)
	... 54 more

[mshabarov]

Thanks for the issue @tk0no ! Do you call invalidate() on the Vaadin Flow class? So VaadinSession might be a Vaadin 8 class. This is one thing to check.
Another one to check (for us) is why does Vaadin 8 servlet handles the request...see com.vaadin.server.VaadinService.handleRequest in the stack trace.

[tk0no]

Thanks for the reply @mshabarov! We are calling VaadinSession.getCurrent().getSession().invalidate() in flow route class instance and it has import com.vaadin.flow.server.VaadinSession;