title: How to check if a file is plain text?
body: <p>In my program, the user can load a file with links (it's a webcrawler), but I need to verify if the file that the user chooses is plain text or something else (only plain text will be allowed).</p>
  
  <p>Is it possible to do this? If it's useful, I'm using JFileChooser to open the file.</p>
  
  <p>EDIT:</p>
  
  <p><strong>What is expected from the user</strong>: a text file containing URLs.</p>
  
  <p><strong>What I want to avoid</strong>: the user loads an MP3 file or a document from the MS Word (examples).</p>