What is the procedure to make a Java EE WebApp with Maven and Intellij?

This is what I do:

* File / New / Project
* Project Type : Maven
* Create From archetype : maven-archetype-webapp

But when I create a servlet IntelliJ shows a symbol on the servlet:
![enter image description here](https://i.stack.imgur.com/LU9OG.jpg)

This symbol is "Java class located out of the source root. Refer to the section Configuring Content Roots for details"

If I launch the project I get an error.

If I mark the "resources" directory as "Sources Root", the project works.

But if I reload Maven (right click / maven / reimport) the resources directory lost the "Source Root" structure.

I think something is wrong in my procedure.