How to add line separator afer every method. like this: <img src="https://i.stack.imgur.com/gp0Kr.png" alt="Line separator android studio">

Simply enable in settings <pre class="prettyprint"><code>Appearance: Show method separators </code></pre> Or hit <kbd>Shift</kbd> 2 times in Editor Area and type <code>method separators</code> <img src="https://i.stack.imgur.com/OoAcb.png" alt="enter image description here">

Go to Preferences > Editor > General > Appearance > Show method separators > check the box <img src="https://i.stack.imgur.com/tQySr.png" alt="enter image description here">