Upload JAR Files
Upload JAR Files
Additional Java libraries can be uploaded to an application-server container through the platform Configuration Manager. After the JAR file is placed in the correct library directory and the server is restarted, the application can use the added dependency.
Before Uploading a JAR File
- Confirm that the library version is compatible with the application-server and JDK versions.
- Check whether the dependency is already included in the application archive or server runtime.
- Back up the existing application-server configuration and libraries.
- Use a trusted JAR source and verify the file integrity where possible.
- For a multi-node layer, plan to upload the same library to every required application-server node.
Avoid duplicate libraries
Uploading another version of a library that is already bundled with the application or server can create class-loading conflicts. Review the existing runtime libraries before adding a JAR.
Upload a JAR through Configuration Manager
Open the application-server configuration
Locate the Java environment in the dashboard and click Config beside the required application-server layer.
Select the target node
When the layer contains several application-server instances, select the node that should receive the JAR file.
Open the library directory
Navigate to the application-server library folder. The exact path depends on the selected stack.
Upload the JAR file
Use the file-manager upload action, select the required .jar file from the local computer, and wait for the upload to complete.
Multi-node environments
Uploading a new file normally affects only the selected node. Repeat the upload for the other application-server instances or use a deployment process that keeps all nodes synchronized.
Common Library Locations
The library directory depends on the Java application server. Verify the path for the stack version running in the environment.
| Application Server | Common Library Location | Notes |
|---|---|---|
| Tomcat | /opt/tomcat/lib | Libraries placed here are available to applications running on the Tomcat instance. |
| TomEE | /opt/tomcat/lib | Use the shared server library directory for dependencies required by multiple applications. |
| Jetty | /opt/jetty/lib | Confirm module and class-loading requirements for the installed Jetty version. |
| GlassFish | /opt/glassfish3/glassfish/lib | Some libraries may need to be managed through GlassFish configuration or its administration console. |
Application-specific dependencies
A dependency needed by only one application can often be packaged inside that application’s WAR or EAR archive instead of being installed as a shared server library.
Restart and Verify the Server
Restart the application server
Restart the affected application-server node so that the runtime loads the newly uploaded library.
Open the application
Access the deployed application and test the function that depends on the uploaded JAR.
Review the logs
Check the application-server logs for missing classes, duplicate classes, version incompatibility, or initialization errors.
Expected Result
The JAR file is stored in the required application-server library directory, loaded after the server restart, and available to the deployed Java application.
Important Notes
- Upload the same JAR version to every application-server node that must use it.
- Restart the affected application server after adding or replacing a shared library.
- Do not overwrite platform-provided libraries without a tested rollback plan.
- Keep a backup of the previous JAR when replacing an existing version.
- Use only trusted libraries and review known security vulnerabilities.
- Consider packaging application-specific dependencies inside the application archive.
Common Issues and Solutions
| Issue | Solution |
|---|---|
| Application still reports a missing class | Confirm the upload path, restart the server, and check whether the JAR contains the required class. |
| Application fails after the upload | Remove or restore the previous library version and review class-loading and compatibility errors in the logs. |
| Only one node works correctly | Upload the same JAR to every node in the application-server layer. |
| Duplicate-class or linkage error appears | Check whether another copy of the dependency is bundled in the application or included by the server. |
| Uploaded file disappears after redeployment | Confirm whether the selected directory is preserved by the container redeployment policy and maintain a repeatable deployment process. |