On 02/07/2017 11:16, Cay Horstmann wrote:
In §7.7, the JLS draft from 2017-06-26 states:
An open module, with the open modifier ... grants access at run time to
types in all its packages, as if all packages had been exported.
...
Distinct from access at compile time and access at run time, the Java
SE Platform provides reflective access via the Core Reflection API
(§1.4)...
So, here is my question. I had thought the purpose of open modules and
opened packages was to be able to access non-public members at runtime
through reflection.
But it appears from the workding of the JLS as if other runtime access
would also be possible. Like what? I mean, if I don't have
compile-time access, what runtime access do I have other than through
reflection? Synthesized byte codes? Method handles? Or did I overlook
something really obvious here?
As it says, an open module grants access at run time to types in all of
the module's packages, as if all packages are exported. This means
bytecode or reflection can be used to access the public classes / public
members in all packages. In addition, the reflection APIs (with
setAccessible or MethodHandles.privateLookupIn) allow for "deep
reflection" so you can reflect on all members of all classes in all
packages.
-Alan
