title: Android structure: Two classes for one activity
body: <p>I am a newbie in android and I am trying to find a good structure for my application but I am not sure how to do it. </p>
  
  <p>I have one activity and one page only gathering information and doing something with it (Pushing it to the API, Calculations, etc...). But I simply do not want to put everything inside the <code>MainActivity.java</code> as it would become a long file with so many functions. So I would like to be able to call these functions from <code>MainActivity.java</code>, and preform them in other classes.</p>
  
  <p>Is there a specific name or way of doing so ? what class would I extend if I create a new one for the same Main Activity to preform the functions being called from there, and keep <code>MainActivity.java</code> short and clean</p>