This solution works in Android Studio 3.0 or later.
- File > Project Structure > Modules > app > Properties tab
Change both of Source Compatibility and Target Compatibility to 1.8
- Edit config file
You can also configure it directly in the corresponding build.gradle file
android {
...
// Configure only for each module that uses Java 8
// language features (either in its source code or
// through dependencies).
compileOptions {
sourceCompatibility JavaVersion.VERSION_1_8
targetCompatibility JavaVersion.VERSION_1_8
}
}