Hi,

Since upgrading to JDK 9 (Gson v2.8.1), we keep getting warning messages like the following when doing JSON-serialization using Gson:

WARNING: An illegal reflective access operation has occurred
WARNING: Illegal reflective access by com.google.gson.internal.ConstructorConstructor (./lib/gson-2.8.1.jar) to constructor java.text.NumberFormat()
WARNING: Please consider reporting this to the maintainers of com.google.gson.internal.ConstructorConstructor
WARNING: Use --illegal-access=warn to enable warnings of further illegal reflective access operations
WARNING: All illegal access operations will be denied in a future release

It seems that with the introduction of modularization in Java 9, reflective access is only permitted to classes within the same module. However, Gson apparently accesses classes in the module java.base (in this example java.text.NumberFormat) which causes above warning message (by default, it is only displayed once on the first illegal reflective access). Since illegal access of this form will be prohibited in future releases (probably in Java 10), and because of this annoying warning message, this should be fixed as soon as possible.

Thanks!