If you have 5 projects that all need the same PostgreSQL JDBC driver, do this:

💡 Troubleshooting Tip: Check Deployment to ensure the JAR is copied to WEB-INF/lib for web projects.

  • EARs: For enterprise apps, include shared libraries in the EAR's lib directory or reference modules that include them.
  • If relying on an application server provided library (e.g., servlet-api.jar), do NOT include duplicates; instead mark the dependency as provided to avoid classloader conflicts.
  • For native libraries (DLL/.so), ensure they are available on the host OS library path or packaged and loaded via System.loadLibrary with correct extraction at runtime.

    • This guide explains how to add external libraries (JAR files) to your JDeveloper project.

    By following these steps, you should be able to successfully import a library into your JDeveloper project.

    For web applications, the safest runtime fix:

    JDeveloper will automatically add it to the deployed WAR file.