Java 9 removes access to various unsupported JDK-internal APIs by default.

Examine the use of unsupported JDK-internal APIs and consider replacing them with supported APIs as recommended in the references.

  • Oracle JDK Documentation: Oracle JDK 9 Migration Guide.
  • OpenJDK Documentation: Java Dependency Analysis Tool, JEP 260: Encapsulate Most Internal APIs, JEP 261: Module System.