To migrate existing Android projects, simply import them using Android Studio:
- In Android Studio, close any projects currently open. You should see the Welcome to Android Studio window.
- Click Import Non-Android Studio project.
- Locate the project you exported from Eclipse, expand it, select the build.gradle file and click OK.
- In the following dialog, leave Use gradle wrapper selected and click OK. (You do not need to specify the Gradle home.)
Android Studio properly updates the project structure and creates the appropriate Gradle build file.