Develop Reference

How to debug java.lang.ClassNotFoundException during Tomcat startup?

When Tomcat loads my war, I get this error:
Exception in thread "ClientMessageReceptor0" java.lang.NoClassDefFoundError: java/net/Inet6Address
at org.jacorb.orb.iiop.IIOPAddress.getNetworkInetAddresses(IIOPAddress.java:675)
at org.jacorb.orb.iiop.IIOPAddress.getLocalHost(IIOPAddress.java:591)
at org.jacorb.orb.iiop.IIOPAddress.getLocalHostAddress(IIOPAddress.java:574)
at org.jacorb.orb.listener.SSLListenerUtil.processException(SSLListenerUtil.java:73)
at org.jacorb.orb.iiop.IIOPConnection.handleCommFailure(IIOPConnection.java:77)
at org.jacorb.orb.etf.StreamConnectionBase.read(StreamConnectionBase.java:139)
at org.jacorb.orb.giop.GIOPConnection.getMessage(GIOPConnection.java:389)
at org.jacorb.orb.giop.GIOPConnection.receiveMessagesLoop(GIOPConnection.java:541)
at org.jacorb.orb.giop.GIOPConnection.receiveMessages(GIOPConnection.java:533)
at org.jacorb.orb.giop.MessageReceptor.doWork(MessageReceptor.java:69)
at org.jacorb.util.threadpool.ConsumerTie.run(ConsumerTie.java:60)
at java.lang.Thread.run(Thread.java:745)
Caused by: java.lang.ClassNotFoundException: Illegal access: this web application instance has been stopped already. Could not load [java.net.Inet6Address]. The following stack trace is thrown for debugging purposes as well as to attempt to terminate the thread which caused the illegal access.
at org.apache.catalina.loader.WebappClassLoaderBase.checkStateForClassLoading(WebappClassLoaderBase.java:1375)
at org.apache.catalina.loader.WebappClassLoaderBase.loadClass(WebappClassLoaderBase.java:1226)
at org.apache.catalina.loader.WebappClassLoaderBase.loadClass(WebappClassLoaderBase.java:1188)
Our application uses Tomcat v9.0.41 and JDK 1.8.0_111 . This same combination works for others in my team and also it worked for me sometime back. I'm not sure what changed now. I have looked at other similar posts and they suggest mismatch between Tomcat and JDK version. But above combination of Tomcat and JDK works for others.
I have removed all other JDK and JRE version on my system.
Ensured JAVA_HOME points to JDK 1.8.0_111 and PATH points to correct JRE.
Any pointers on how to debug this further? Can I turn on some logging during Tomcat startup to see what paths are being used by Tomcat? Any suggestions are highly appreciated :).

How to get KQueue to be available in Java in OSX?

My packages are as following:
implementation("io.netty:netty-transport-native-epoll:$nettyVersion")
implementation("io.netty:netty-transport-native-kqueue:$nettyVersion")
implementation("io.netty:netty-transport-native-epoll:$nettyVersion:linux-aarch_64")
implementation("io.netty:netty-transport-native-epoll:$nettyVersion:linux-x86_64")
implementation("io.netty:netty-transport-native-kqueue:$nettyVersion:osx-x86_64")
Gradle showing the package getting installed correctly: (where <source> is the path to our internal library storage)
Cached resource <source>/releases/io/netty/netty-transport-native-kqueue/4.1.78.Final/netty-transport-native-kqueue-4.1.78.Final-osx-x86_64.jar is up-to-date (lastModified: Fri Jun 24 17:45:28 PDT 2022).
Gradle output showing the system:
------------------------------------------------------------------------
Detecting the operating system and CPU architecture
------------------------------------------------------------------------
os.detected.name=osx
os.detected.arch=x86_64
os.detected.version=12.4
os.detected.version.major=12
os.detected.version.minor=4
os.detected.classifier=osx-x86_64
Simplest way I can reproduce is:
KQueue.isAvailable()
returns false.
If I run the following to get more information:
KQueue.unavailabilityCause().printStackTrace();
I get: (removed repeating or unnecessary stack traces)
java.lang.UnsatisfiedLinkError: could not load a native library: netty_transport_native_kqueue_x86_64
at io.netty.util.internal.NativeLibraryLoader.load(NativeLibraryLoader.java:239)
at io.netty.channel.kqueue.Native.loadNativeLibrary(Native.java:155)
...
Suppressed: java.lang.UnsatisfiedLinkError: no netty_transport_native_kqueue_x86_64 in java.library.path: /Users/kdilsiz/Library/Java/Extensions:/Library/Java/Extensions:/Network/Library/Java/Extensions:/System/Library/Java/Extensions:/usr/lib/java:.
...
Am I not supposed to be able to run this code? What am I missing?
If I search online for the error, it shows outdated Netty package loading errors (only showing up in debug level logging). This is NOT my problem. The package loads correctly when I run gradle and I can see it is being cached/loaded with gradle -info --refresh-dependencies.

It was due to one of the dependencies importing netty-all. This was causing the Kqueue packages to be imported twice and with different versions.
The problem was that I did not fully read the stack trace from:
KQueue.unavailabilityCause().printStackTrace();
In the end of that stack trace, it said:
Caused by: java.lang.IllegalStateException: Multiple resources found for 'META-INF/native/libnetty_transport_native_kqueue_x86_64.jnilib' with different content:
...
After that, I was able to find where the package was coming from and fix it. Then I was able to locally run the Java Code to run domain socket and test it locally.
I used IntelliJ to run it after the fix. (VsCode had a problem even after the fix, hence wanted to mention it)

Jenkins Pipeline error when building

We have been trying to get Pipeline working on Jenkins 2.107 however it keeps coming up with an error that i have struggled to locate online. We have a Windows 2008 R2 server with Jenkins running as a service.
I have installed the pipeline plugin and set up the Hello World provided to test it. As soon s it starts to build it throws this error to the console.
Running in Durability level: MAX_SURVIVABILITY [BFA] Scanning build
for known causes... [BFA] No failure causes found [BFA] Done. 0s
java.lang.ClassNotFoundException:
org.kohsuke.groovy.sandbox.GroovyInterceptor at
jenkins.util.AntClassLoader.findClassInComponents(AntClassLoader.java:1374)
at jenkins.util.AntClassLoader.findClass(AntClassLoader.java:1327)
at jenkins.util.AntClassLoader.loadClass(AntClassLoader.java:1080)
at java.lang.ClassLoader.loadClass(ClassLoader.java:357) Caused:
java.lang.NoClassDefFoundError:
org/kohsuke/groovy/sandbox/GroovyInterceptor at
org.jenkinsci.plugins.workflow.cps.CpsGroovyShellFactory.makeClassLoader(CpsGroovyShellFactory.java:113)
at
org.jenkinsci.plugins.workflow.cps.CpsGroovyShellFactory.build(CpsGroovyShellFactory.java:119)
at
org.jenkinsci.plugins.workflow.cps.CpsFlowExecution.parseScript(CpsFlowExecution.java:556)
at
org.jenkinsci.plugins.workflow.cps.CpsFlowExecution.start(CpsFlowExecution.java:520)
at
org.jenkinsci.plugins.workflow.job.WorkflowRun.run(WorkflowRun.java:319)
at
hudson.model.ResourceController.execute(ResourceController.java:97)
at hudson.model.Executor.run(Executor.java:429) Finished: FAILURE
We are running Java 8 and i have set Jenkins to use Java 8 in the config file. I have researched this error but can't seem to find something similar.
We have another server which runs pipeline fine however the differences are that this is windows 2012 server and it is running an older version of Jenkins and Java. Other than the two differences all plugins and config match.

I had this error and resolved it by upgrading the Script Security plugin to version 1.44 (had 1.41).

Lombok Eclipse issue: "Requesting Java AST from selection"

I have Lombok plugin installed in my Eclipse. It was working fine till now since many days. All of a sudden I am frequently getting a popup in my Eclipse with the following details:
An error has occurred. See error log for more details.
lombok/launch/PatchFixesHider$PatchFixes
An internal error occurred during: "Requesting Java AST from selection".
lombok/launch/PatchFixesHider$PatchFixes
The Eclipse error log has this:
!ENTRY org.eclipse.ui.workbench 4 2 2016-08-29 13:18:38.631
!MESSAGE Problems occurred when invoking code from plug-in: "org.eclipse.ui.workbench".
!STACK 0
java.lang.LinkageError: lombok/launch/PatchFixesHider$PatchFixes
at org.eclipse.jdt.internal.ui.search.OccurrencesFinder.addUsage(OccurrencesFinder.java)
at org.eclipse.jdt.internal.ui.search.OccurrencesFinder.visit(OccurrencesFinder.java:158)
at org.eclipse.jdt.core.dom.QualifiedName.accept0(QualifiedName.java:168)
at org.eclipse.jdt.core.dom.ASTNode.accept(ASTNode.java:2711)
at org.eclipse.jdt.core.dom.ASTNode.acceptChild(ASTNode.java:2759)
at org.eclipse.jdt.core.dom.PackageDeclaration.accept0(PackageDeclaration.java:225)
at org.eclipse.jdt.core.dom.ASTNode.accept(ASTNode.java:2711)
at org.eclipse.jdt.core.dom.ASTNode.acceptChild(ASTNode.java:2759)
Eclipse version :
Eclipse Java EE IDE for Web Developers.
Version: Neon Release (4.6.0)
Build id: 20160613-1800
This popup is occurring quite frequently and its very annoying.Does anyone knows the solution to fix this?

Removed older jar and updated with latest lombok jar (version 1.16.10).. restarted my system. this fixed this issue. Not sure what was the cause of this issue though.

Had the same issue, restarting Eclipse was sufficient for me.

Worklight project upgrade error

I encountered a problem with Worklight project that is new technology for me.
Error while upgrading Worklight project from version 6.1.0.00-20131126-0630 to 6.1.0.01-20140821-0406 (also tried 6.1.0.02-21041216-0421). Error message:
Unexpected error during upgrade: java.lang.NullPointerException at com.worklight.upgrader.internal.Zipper.addFolderToZip(Zipper.java:190)
at com.worklight.upgrader.internal.Zipper.addFolderToZip(Zipper.java:202) at com.worklight.upgrader.internal.Zipper.addFolderToZip(Zipper.java:202)
at com.worklight.upgrader.internal.Zipper.addFolder(Zipper.java:106) at com.worklight.upgrader.internal.Zipper.addFolder(Zipper.java:91)
at com.worklight.upgrader.WLUpgradeEngine.backupCurrentProject(WLUpgradeEngine.java:645) at com.worklight.upgrader.WLUpgradeEngine.performUpgrade(WLUpgradeEngine.java:294)
at com.worklight.upgrader.WLUpgradeEngine.upgradeProject(WLUpgradeEngine.java:188) at com.worklight.studio.plugin.upgrader.WLUpgraderWorkspaceJob.runInWorkspace(WLUpgraderWorkspaceJob.java:127)
at org.eclipse.core.internal.resources.InternalWorkspaceJob.run(InternalWorkspaceJob.java:38) at org.eclipse.core.internal.jobs.Worker.run(Worker.java:53)
Eclipse Java EE IDE for Web Developers.
Version: Kepler Service Release 2 Build id: 20140224-0627
Win8.1 x64
Any help or suggestions are very appreciated.

All the builds you have tried are very, very old.
As an IBM customer you should download the latest available iFix for your Studio installation from IBM Fix Central. The latest should be from July 2015.
Please try again with that version.
You can also attempt to delete the wlBuildResources folder per the instructions in this question: Worklight - FWLST1040E: android build failed: java.io.FileNotFoundException
Finally, if this is still happening also with the latest available iFix (see above), provide a project that this issue is reproducible with so that it could be debugged.