Library accesses GSON internal API, breaks with gson on the module path

[mikehearn]

Describe the bug

The ReflectionCheckingTypeAdapterFactory class accesses a GSON internal class directly. This breaks when GSON is placed on the module path due to encapsulation.

java.lang.IllegalAccessError: class com.stripe.net.ReflectionCheckingTypeAdapterFactory (in unnamed module @0x69a3d1d) cannot access class com.google.gson.internal.bind.ReflectiveTypeAdapterFactory$Adapter (in module com.google.gson) because module com.google.gson does not export com.google.gson.internal.bind to unnamed module @0x69a3d1d @ com.stripe.net.ReflectionCheckingTypeAdapterFactory.create(Unknown Source)

To Reproduce

Place gson on the module path and then try to use the Stripe API.

Expected behavior

There are a few possible fixes that spring to mind:

1. This class looks like a utility / assertion checking class, so it could be disabled in production code paths.
2. Instead of using instanceof, the class name could maybe be checked using reflection?
3. The IllegalAccessError could be caught, and that used to disable the check at runtime.

Code snippets

No response

OS

macOS

Java version

Java 17

stripe-java version

22.1.0

API version

2022-11-15

Additional context

A workaround is to place gson on the classpath instead of the module path. One could probably also use --add-opens.

[richardm-stripe]

Relates to #1197.

[mikehearn]

Thanks!

[richardm-stripe]

Released in https://github.com/stripe/stripe-java/releases/tag/v22.4.0