Historically then all standard / Java SE types have been visible via the boot loader. This changes in JDK 9 because several java.* modules will be defined to the extension class loader. The motivation for moving these modules to a lesser privileged loader are (a) to allow for upgrading, the EE owned modules in particular, and (b) security as these modules should need all permissions.

We need to consider adding a method to jl.ClassLoader to return a class loader that will guarantee to have visibility of all standard types. Many custom class loaders use the boot loader as their parent on the assumption that all standard types are visible via the parent. Class loaders that default to the system class loader as the parent are of course not impacted by the changes in JDK 9.