Details
Major Description
In case users open bookmarked deep links (including page version) or the page currently displayed expired, in some cases there are NPEs in the MountedMapper:
09:48:55,229-[ajp-nio-8154-exec-6] ERROR -ErrorPage - java.lang.NullPointerException at org.apache.wicket.core.request.mapper.MountedMapper.checkPageClass(MountedMapper.java:256) at org.apache.wicket.core.request.mapper.AbstractBookmarkableMapper.mapHandler(AbstractBookmarkableMapper.java:400) at org.apache.wicket.core.request.mapper.MountedMapper.mapHandler(MountedMapper.java:154) at org.apache.wicket.request.mapper.CompoundRequestMapper.mapHandler(CompoundRequestMapper.java:210) at org.apache.wicket.request.cycle.RequestCycle.mapUrlFor(RequestCycle.java:449) at org.apache.wicket.request.handler.render.WebPageRenderer.respond(WebPageRenderer.java:186) at org.apache.wicket.core.request.handler.RenderPageRequestHandler.respond(RenderPageRequestHandler.java:202) at org.apache.wicket.request.cycle.RequestCycle$HandlerExecutor.respond(RequestCycle.java:912) at org.apache.wicket.request.RequestHandlerExecutor.execute(RequestHandlerExecutor.java:65) at org.apache.wicket.request.cycle.RequestCycle.execute(RequestCycle.java:283) at org.apache.wicket.request.cycle.RequestCycle.processRequest(RequestCycle.java:253) at org.apache.wicket.request.cycle.RequestCycle.processRequestAndDetach(RequestCycle.java:221) at org.apache.wicket.protocol.http.WicketFilter.processRequestCycle(WicketFilter.java:262) at org.apache.wicket.protocol.http.WicketFilter.processRequest(WicketFilter.java:204) at org.apache.wicket.protocol.http.WicketFilter.doFilter(WicketFilter.java:286) at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:239) at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206) at org.springframework.orm.hibernate3.support.OpenSessionInViewFilter.doFilterInternal(OpenSessionInViewFilter.java:230) at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:106) at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:239) at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206) at de.bps.blok.utils.NoJSessionIdInUrlFilter.doFilter(NoJSessionIdInUrlFilter.java:44) at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:239) at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206) at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:219) at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:106) at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:502) at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:142) at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:79) at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:88) at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:518) at org.apache.coyote.ajp.AbstractAjpProcessor.process(AbstractAjpProcessor.java:844) at org.apache.coyote.AbstractProtocol$AbstractConnectionHandler.process(AbstractProtocol.java:668) at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.doRun(NioEndpoint.java:1527) at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.run(NioEndpoint.java:1484) at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142) at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617) at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61) at java.lang.Thread.run(Thread.java:745)
Reason seems to be in PageProvider.getPageClass(). This may return null if hasPageInstance() returns false. In that case a NPE is thrown as shown in the stacktrace.
Example:
Mounting:
mount(new MountedMapper("page/${page}", BlokPage.class));
Request logger:
09:48:55,246-[ajp-nio-8154-exec-6] INFO -RequestLogger -startTime="2017-10-05 07:48:55,093",duration=153,url="https://server/path/page/home?1",event={handler=RenderPageRequestHandler,data={pageId=1,pageParameters={null},renderCount=null}},response={handler=RenderPageRequestHandler,data={pageClass=de.bps.blok.page.simple.ErrorPage,pageId=0,pageParameters={},renderCount=0}},sessionid="A5527CCEAEE7334A805F9EF09D30A7BB",sessionsize=2710,sessioninfo={;page/home?1},sessionstart="2017-10-05 07:48:55,231",requests=2,totaltime=153,activerequests=0,maxmem=2147M,total=1073M,used=198M