NPE in localhost.log if application fails to start

[alexbudarov]

Environment

• Operating system: Linux, tomcat 9

Description of the bug or enhancement

See this forum post:
https://www.cuba-platform.com/discuss/t/deploy-to-linux-environment/11268/8?u=alexbudarov

Exception:

Click to expand

28-Jan-2020 10:36:22.326 SEVERE [main] org.apache.catalina.core.StandardContext.listenerStop Exception sending context destroyed event to listener instance of class [com.haulmont.cuba.core.sys.singleapp.SingleAppCoreServletListener]
java.lang.NullPointerException
at com.haulmont.cuba.core.sys.AbstractWebAppContextLoader.contextDestroyed(AbstractWebAppContextLoader.java:106)
at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
at java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.base/java.lang.reflect.Method.invoke(Method.java:566)
at org.springframework.util.ReflectionUtils.invokeMethod(ReflectionUtils.java:215)
at com.haulmont.cuba.core.sys.singleapp.SingleAppCoreServletListener.contextDestroyed(SingleAppCoreServletListener.java:99)
at org.apache.catalina.core.StandardContext.listenerStop(StandardContext.java:4732)
at org.apache.catalina.core.StandardContext.stopInternal(StandardContext.java:5396)
at org.apache.catalina.util.LifecycleBase.stop(LifecycleBase.java:257)
at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:187)
at org.apache.catalina.core.ContainerBase.addChildInternal(ContainerBase.java:717)
at org.apache.catalina.core.ContainerBase.addChild(ContainerBase.java:690)
at org.apache.catalina.core.StandardHost.addChild(StandardHost.java:705)
at org.apache.catalina.startup.HostConfig.deployWAR(HostConfig.java:978)
at org.apache.catalina.startup.HostConfig$DeployWar.run(HostConfig.java:1849)
at java.base/java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:515)
at java.base/java.util.concurrent.FutureTask.run(FutureTask.java:264)
at org.apache.tomcat.util.threads.InlineExecutorService.execute(InlineExecutorService.java:75)
at java.base/java.util.concurrent.AbstractExecutorService.submit(AbstractExecutorService.java:118)
at org.apache.catalina.startup.HostConfig.deployWARs(HostConfig.java:773)
at org.apache.catalina.startup.HostConfig.deployApps(HostConfig.java:427)
at org.apache.catalina.startup.HostConfig.start(HostConfig.java:1576)
at org.apache.catalina.startup.HostConfig.lifecycleEvent(HostConfig.java:309)
at org.apache.catalina.util.LifecycleBase.fireLifecycleEvent(LifecycleBase.java:123)
at org.apache.catalina.util.LifecycleBase.setStateInternal(LifecycleBase.java:423)
at org.apache.catalina.util.LifecycleBase.setState(LifecycleBase.java:366)
at org.apache.catalina.core.ContainerBase.startInternal(ContainerBase.java:936)
at org.apache.catalina.core.StandardHost.startInternal(StandardHost.java:841)
at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:183)
at org.apache.catalina.core.ContainerBase$StartChild.call(ContainerBase.java:1384)
at org.apache.catalina.core.ContainerBase$StartChild.call(ContainerBase.java:1374)
at java.base/java.util.concurrent.FutureTask.run(FutureTask.java:264)
at org.apache.tomcat.util.threads.InlineExecutorService.execute(InlineExecutorService.java:75)
at java.base/java.util.concurrent.AbstractExecutorService.submit(AbstractExecutorService.java:140)
at org.apache.catalina.core.ContainerBase.startInternal(ContainerBase.java:909)
at org.apache.catalina.core.StandardEngine.startInternal(StandardEngine.java:262)
at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:183)
at org.apache.catalina.core.StandardService.startInternal(StandardService.java:421)
at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:183)
at org.apache.catalina.core.StandardServer.startInternal(StandardServer.java:932)
at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:183)
at org.apache.catalina.startup.Catalina.start(Catalina.java:633)
at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
at java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.base/java.lang.reflect.Method.invoke(Method.java:566)
at org.apache.catalina.startup.Bootstrap.start(Bootstrap.java:344)
at org.apache.catalina.startup.Bootstrap.main(Bootstrap.java:479)

CUBA application fails to start, and tomcat invokes AbstractWebAppContextLoader.contextDestroyed callback.

Our code fails with NPE on this line:

        applicationContext.getBean(Events.class)
                .publish(new ServletContextDestroyedEvent(
                                servletContextEvent.getServletContext(),
                                applicationContext
                        ));

Here probably applicationContext is null.
It is not a super problem but it can confuse user who is doing deployment troubleshooting.

[alexbudarov]

I'll try to reproduce it later.

[alexbudarov]

Easy to reproduce:

• Create empty project on CUBA 7.1.4
• Create invalid bean defintion in core spring.xml:

<bean id="cuba_FileStorage" class="com.haulmont.cuba.core.app.filestorage.amazon.FooFileStorage"/>

• Start application server.

You will see this exception in deploy/tomcat/logs/localhost.log