[WICKET-6277] Broadcasting ClosedMessage about the JSR 356 WebSocket connection after the container was turned off

• Type: Bug
• Status: Closed
• Priority: Minor
• Resolution: Fixed
• Affects Version/s: 7.4.0
• Fix Version/s: 7.6.0, 8.0.0-M3
• Component/s: wicket-native-websocket
• Environment: Windows 10, Tomcat 8.0.33, JDK 1.8.0_91
• Assignee: Martin Tzvetanov Grigorov
• Reporter: Jan Krakora
• Created: 15/Nov/16 16:26
• Updated: 16/Nov/16 09:51
• Resolved: 15/Nov/16 20:53

Description

Whenever is the servlet container (Tomcat in my case) turned off it closes all established ws connections. Wicket reacts to that by broadcasting a ClosedMessage to a Page bounded to that connection. And that is a problem since before that, org.apache.wicket.protocol.http.WicketFilter#destroy() is called and (among others) the IPageManager is destroyed.

It leads to a NPE:

java.lang.NullPointerException: null
	at org.apache.wicket.page.PageStoreManager$SessionEntry.getPage(PageStoreManager.java:203)
	at org.apache.wicket.page.PageStoreManager$PersistentRequestAdapter.getPage(PageStoreManager.java:357)
	at org.apache.wicket.page.AbstractPageManager.getPage(AbstractPageManager.java:82)
	at org.apache.wicket.page.PageManagerDecorator.getPage(PageManagerDecorator.java:50)
	at org.apache.wicket.page.PageAccessSynchronizer$2.getPage(PageAccessSynchronizer.java:246)
	at org.apache.wicket.protocol.ws.api.AbstractWebSocketProcessor.getPage(AbstractWebSocketProcessor.java:315)
	at org.apache.wicket.protocol.ws.api.AbstractWebSocketProcessor.broadcastMessage(AbstractWebSocketProcessor.java:243)
	at org.apache.wicket.protocol.ws.api.AbstractWebSocketProcessor.onClose(AbstractWebSocketProcessor.java:182)
	at org.apache.wicket.protocol.ws.javax.WicketEndpoint.onClose(WicketEndpoint.java:71)
	at org.apache.tomcat.websocket.WsSession.fireEndpointOnClose(WsSession.java:541)
	at org.apache.tomcat.websocket.WsSession.doClose(WsSession.java:490)
	at org.apache.tomcat.websocket.WsSession.close(WsSession.java:454)
	at org.apache.tomcat.websocket.WsWebSocketContainer.destroy(WsWebSocketContainer.java:926)
	at org.apache.tomcat.websocket.server.WsServerContainer.destroy(WsServerContainer.java:285)
	at org.apache.tomcat.websocket.server.WsContextListener.contextDestroyed(WsContextListener.java:48)
	at org.apache.catalina.core.StandardContext.listenerStop(StandardContext.java:4856)
	at org.apache.catalina.core.StandardContext.stopInternal(StandardContext.java:5474)
	at org.apache.catalina.util.LifecycleBase.stop(LifecycleBase.java:224)
	at org.apache.catalina.core.ContainerBase$StopChild.call(ContainerBase.java:1424)
	at org.apache.catalina.core.ContainerBase$StopChild.call(ContainerBase.java:1413)
	at java.util.concurrent.FutureTask.run(FutureTask.java:266)
	at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)
	at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)
	at java.lang.Thread.run(Thread.java:745)

I think it would be good idea to NOT broadcast ClosedMessage when the Application is already destroyed.