grpc-java/examples/android/helloworld/app
Eric Anderson a81bf14f1f Upgrade to Guava 30.1, which warns on Java 7
This change can have large impact from two aspects:
1. It calls out a _large_ impact on the _few_ Java 7 users.
2. It may have _small_ impact on the _many_ Android users.

https://github.com/grpc/grpc-java/issues/4671 tracks gRPC's removal of
Java 7 support. We are quite eager to drop Java 7 support as that would
allow using new language features like default methods. Guava is also
dropping Java 7 support and starting in 30.1 it will warn when used on
Java 7. The purpose of the warning is to help discover users that are
negatively impacted by dropping Java 7 before it becomes a bigger
problem.

The Guava logging check was implemented in such a way that there is an
optional class that uses Java 8 bytecode. While the class is optional at
runtime, the Android build system notices when dexing and fails if
Java 8 language featutres are not enabled. We believe this will not be a
problem for most Android users, but they may need to add to their build:

```
android {
    compileOptions {
        sourceCompatibility JavaVersion.VERSION_1_8
        targetCompatibility JavaVersion.VERSION_1_8
    }
}
```

See also https://github.com/google/guava/releases/tag/v30.1
2021-04-19 09:16:00 -07:00
..
src/main all: normalize copyright header 2018-05-03 14:55:21 -07:00
build.gradle Upgrade to Guava 30.1, which warns on Java 7 2021-04-19 09:16:00 -07:00
proguard-rules.pro core: Use Class.forName(String) in provider for Android 2017-07-19 10:15:03 -07:00