[android] How to add new activity to existing project in Android Studio?

I think natually do it is straightforward, whether Intellij IDEA or Android Studio, I always click new Java class menu, and then typing the class name, press Enter to create. after that, I manually typing "extends Activity" in the class file, and then import the class by shortcut key. finally, I also manually override the onCreate() method and invoke the setContentView() method.