Then a function call on Web is used and a GET request is send.
I wanted to ask how to implement the same functionality using Android Studio. Maybe a name of component or function in Java Code.
Take a look at this site: http://www.appinventor.org/jBridgeIntro
The library file (http://www.appinventor.org/javaBridge/downloads/AppInventor-JavaLibrary.jar) can be added as a library file for your project.
You then get all the 'blocks' as in AppInventor, but they're pre-prepared Java classess etc.