jdeps -jdkinternals should detect any JDK internal API removed in JDK 9 and flag that in the output.
One idea is to generate the list of JDK 8 internal APIs at build time so that jdeps can determine if this has been removed in JDK 9.
One idea is to generate the list of JDK 8 internal APIs at build time so that jdeps can determine if this has been removed in JDK 9.