Question

From what I know, we can only make inner classes private.

Is there any way to make a top level class private in java?

Answer 1

No, as specified in JLS:

Not all modifiers are applicable to all kinds of class declarations.
The access modifier public pertains only to top level classes (§7.6)
and to member classes (§8.5, §9.5), and is discussed in §6.6, §8.5 and
§9.5. The access modifiers protected and private pertain only to
member classes within a directly enclosing class declaration (§8.5)
and are discussed in §8.5.1. The access modifier static pertains only
to member classes (§8.5, §9.5). A compile-time error occurs if the
same modifier appears more than once in a class declaration.