How to resolve OSGi bundle startup NoClassDefFoundError errors using boot delegation?
Problem
OSGi bundles or plugins may fail to resolve or start, affecting application startup. The following errors may be displayed in the terminal output or application error logs:
"java.lang.NoClassDefFoundError: com/manageengine/apminsight/agent/JavaAgent"
A ClassNotFoundException for any com.manageengine.* class is the same issue.
Cause
OSGi bundles run in isolated class loaders and may not be able to access JVM-internal packages or externally injected classes, such as those provided by monitoring agents, unless the required packages are explicitly boot-delegated to the parent class loader.
When boot delegation is not configured or is configured incorrectly, the OSGi framework cannot access the APM Insight Java agent classes because the agent package is not included in the boot delegation configuration. This causes the OSGi bundle or plugin to fail to resolve or start.
Solution
Add the APM Insight Java agent package, com.manageengine.*, to the existing boot delegation Java property.
For example:
-Dorg.osgi.framework.bootdelegation=com.sun.*,com.manageengine.*
Append com.manageengine.* to the existing boot delegation values. Do not remove the existing values.
Platform-specific configuration
Platform-specific configuration
The platform-specific properties and configuration locations are listed in the source document.
Platform | Property | Configuration location |
Liferay DXP | module.framework.properties.org.osgi.framework.bootdelegation | portal-ext.properties |
Atlassian Jira/Confluence | -Datlassian.org.osgi.framework.bootdelegation.extra | setenv.sh |
Adobe Experience Manager (Sling) | -Dorg.osgi.framework.bootdelegation | sling.properties |
Other OSGi platforms/bundled applications | -Dorg.osgi.framework.bootdelegation | Startup script, existing JAVA_OPTS, or another location where Java properties are maintained |
Restart the application
After adding the com.manageengine.* package to the appropriate boot delegation property, restart the application server for the changes to take effect.
Summary
If an OSGi-based application fails to start with a NoClassDefFoundError or ClassNotFoundException error message for an APM Insight Java agent class, verify that com.manageengine.* has been added to the platform’s existing boot delegation configuration.