Getting java.lang.ClassNotFoundException: org.eclipse.jetty.servlet.listener.IntrospectorCleaner - jetty

Question

I'm using Jetty as an embedded web server within OSGi and spring-dm environment. All my bundles and war files are deployed successfully. However I'm observing the following warning in my logs:
2015-03-25 17:32:13.748:WARN:oejw.StandardDescriptorProcessor:Could not instantiate listener org.eclipse.jetty.servlet.listener.IntrospectorCleaner
java.lang.ClassNotFoundException: org.eclipse.jetty.servlet.listener.IntrospectorCleaner
at java.net.URLClassLoader$1.run(URLClassLoader.java:366)
at java.net.URLClassLoader$1.run(URLClassLoader.java:355)
at java.security.AccessController.doPrivileged(Native Method)
at java.net.URLClassLoader.findClass(URLClassLoader.java:354)
at java.lang.ClassLoader.loadClass(ClassLoader.java:425)
at java.net.FactoryURLClassLoader.loadClass(URLClassLoader.java:789)
at java.lang.ClassLoader.loadClass(ClassLoader.java:358)
at org.eclipse.jetty.server.handler.ContextHandler.loadClass(ContextHandler.java:1517)
at org.eclipse.jetty.webapp.StandardDescriptorProcessor.visitListener(StandardDescriptorProcessor.java:1863)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:606)
at org.eclipse.jetty.webapp.IterativeDescriptorProcessor.visit(IterativeDescriptorProcessor.java:85)
at org.eclipse.jetty.webapp.IterativeDescriptorProcessor.process(IterativeDescriptorProcessor.java:72)
at org.eclipse.jetty.webapp.MetaData.resolve(MetaData.java:366)
at org.eclipse.jetty.webapp.WebAppContext.startContext(WebAppContext.java:1250)
at org.eclipse.jetty.server.handler.ContextHandler.doStart(ContextHandler.java:710)
at org.eclipse.jetty.webapp.WebAppContext.doStart(WebAppContext.java:494)
at org.eclipse.jetty.util.component.AbstractLifeCycle.start(AbstractLifeCycle.java:64)
at org.springframework.osgi.web.deployer.jetty.JettyWarDeployer.startWebAppContext(JettyWarDeployer.java:218)
at org.springframework.osgi.web.deployer.jetty.JettyWarDeployer.startDeployment(JettyWarDeployer.java:123)
at org.springframework.osgi.web.deployer.support.AbstractWarDeployer.deploy(AbstractWarDeployer.java:93)
at org.springframework.osgi.web.extender.internal.activator.WarLoaderListener$DeploymentManager$DeployTask.doRun(WarLoaderListener.java:261)
at org.springframework.osgi.web.extender.internal.activator.WarLoaderListener$DeploymentManager$BaseTask.run(WarLoaderListener.java:219)
at org.springframework.scheduling.timer.DelegatingTimerTask.run(DelegatingTimerTask.java:70)
at java.util.TimerThread.mainLoop(Timer.java:555)
at java.util.TimerThread.run(Timer.java:505)
Though this warning is not impacting any functionality, i'm still curious to know why this error is happening. With little debugging I can see that the package "org.eclipse.jetty.servlet.listener" is not imported by any of the modules. I explicitly added this import to jetty-webapp and spring-osgi-web bundles, but that didn't help either.

Answer 1

Upgrade your version of Jetty, you have a very old version with a faulty manifest.
This was fixed well over a year ago.
$ cd jetty-distribution-9.2.10.v20150310
$ jar -xvf lib/jetty-servlet-9.2.10.v20150310.jar META-INF/MANIFEST.MF
inflated: META-INF/MANIFEST.MF
$ grep -A3 Export-Package META-INF/MANIFEST.MF
Export-Package: org.eclipse.jetty.servlet;version="9.2.10",org.eclipse
.jetty.servlet.jmx;version="9.2.10",org.eclipse.jetty.servlet.listene
r;version="9.2.10"
Bundle-Classpath: .