Update protobuf-java-util gson dep from v2.7 to v2.8.1

[bootstraponline]

protobuf-java-util isn't using the latest gson. I had to add a gradle exclude rule. It'd be nice to update to the latest stable version.

[liujisi]

Will the 2.8.1 be binary compatible with 2.7? I'm just cautious about whether this will break other users of protobuf.

[bootstraponline]

Will the 2.8.1 be binary compatible with 2.7?

I'm not sure. Is there a way to tell?

[liujisi]

@xfxyjwf

[xfxyjwf]

Are you directly depending on a newer version of gson? If so, can't gradle pick the newer version automatically?

[bootstraponline]

I have to do this:

androidTestCompile('io.grpc:grpc-protobuf:1.5.0') {
  exclude group: 'com.google.code.gson', module: 'gson'
}

It works fine so there's no problem. I was just wondering when these dependencies get updated in protobuf-java-util after upstream has made a new stable release?

It's possible that upgrading would break people.

[xfxyjwf]

What happens if you don't use "exclude ..."?

[bootstraponline]

What happens if you don't use "exclude ..."?

This:

Error:Conflict with dependency 'com.google.code.gson:gson' in project ':app'. Resolved versions for app (2.8.1) and test app (2.7) differ. See http://g.co/androidstudio/app-test-app-conflict for details.

[xfxyjwf]

This seems an issue in your configuration. Have you tried the suggestions in the linked android studio doc? Specifically it suggests:

If the error is about an indirect dependency (a library you didn't mention
in your build.gradle), just add a dependency for the newer version to the
configuration ("compile" or "androidTestCompile") that needs it.

[bootstraponline]

Have you tried the suggestions in the linked android studio doc?

The app is setting the required version of gson via an indirect dependency. If I explicitly depend on a version of gson, that will work for now but may break in the future.

Excluding means I'm using the same version of gson as the app, regardless of which version that happens to be. I don't have to update it in the future.

Ideally the dependencies would update over time. If gson ever broke their API then this exclude strategy would stop working. I'm not sure what kind of guarantees they provide around API stability.

To clarify there are a few options which work:

• Explicitly depend on gson & update version over time
• Exclude gson from grpc-protobuf

I'm mostly interested in why grpc-protobuf depends on gson from 2016. It sounds like there are compatibility concerns around upgrading.