Hidden classes could be coming to Java
A proposal before the OpenJDK development team would add hidden classes to Java, a capability intended to improve the efficiency of language implementations built on the JVM.
Hidden classes are classes that cannot be used directly by the bytecode of other classes, according to the JDK Enhancement Proposal. Rather, hidden classes are intended to be used by frameworks that generate classes at runtime and use them indirectly via reflection. A hidden class can be defined as a member of an access control nest and may be weakly referenced by its class loader. There is no timetable yet for when hidden classes might appear in Java.