title: Intellij IDEA doesn't recognize java file: blue square in directory
body: <p>I have a project structure like this:</p>
  
  <p><a href="https://i.stack.imgur.com/qSic5.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/qSic5.png" alt="enter image description here"></a></p>
  
  <pre><code>src (sources root)
  ---main  
  -------java (sources root)
  -----------com
  --------------requests
  ----------------------File1.java (needs to be package com.requests)
  ----------------------File2.java (needs to be package com.requests)
  ----------------------File3.java (needs to be package com.requests)
  --------------things
  --------------util
  --------------web
  -------resources
  ----------------images
  -------webapp
  -------------WEB-INF
  --------------------classes
  ---------------------------com
  ------------------------------requests
  ------------------------------things
  ------------------------------util
  ------------------------------web
  ---------------------lib
  </code></pre>
  
  <p>However, <code>File1.java</code>, <code>File2.java</code> and <code>File3.java</code> don't seem to be recognized as Java files and I can't compile them:</p>
  
  <p><a href="https://i.stack.imgur.com/XyVOX.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/XyVOX.png" alt="enter image description here"></a></p>
  
  <p>Why? How do I fix it?</p>