title: How to use org.apache.commons package?
body: <p>On various web examples I see imports such as:</p>
  
  <pre><code>import org.apache.commons.net.ftp.FTPClient;
  </code></pre>
  
  <p>I don't understand how to use these, and the apache website is fairly unclear. How to I use these classes? I'm expecting I need to download something, but a little direction would be greatly appreciated.</p>