As many Java protobuf users know, there is a
protobuf-javalite that doesn't support Java protobuf reflection (descriptors aren't available at runtime). This has a much smaller code size (including fewer methods), making it very useful for Android applications. Because of this, all of Google's Android apps are now built with Java proto-lite. The j2objc protobuf API supports reflection, but since j2objc's main use is to share code with Android, it seems reasonable that j2objc move to only supporting Java proto-lite.
Does anyone's app require the full Java protobuf API? If you don't know, try switching to
protobuf-javalite and see if it still builds and tests successfully (if nothing else, your Android app will be smaller).
Please let us know if your app depends upon full Java protobuf features. If we don't hear from anyone, we'll assume we can just move to the lite API. Although the j2objc runtime is implemented differently than the Java runtimes, we should still see a code size reduction in iOS apps that use j2objc.