An Android APK file contains all the open-source Java files used to set up and run the Google Android app. You can extract these files and load them into your local ...

Android Studio will display a banner asking you to configure your project to support Kotlin; click the ‘Configure’ link and follow the onscreen instructions. Convert existing Java files to Kotlin.

Java is one of the “official” languages that Google supports for Android development — the ... Even the main Java file in our program, MainActivity, is written in camelCase!