title: How to cancel Files.copy() in Java?
body: <p>I'm using Java NIO to copy something:</p>
  
  <pre><code>Files.copy(source, target);
  </code></pre>
  
  <p>But I want to give users the ability to cancel this (e.g. if the file is too big and it's taking a while).</p>
  
  <p>How should I do this?</p>