title: New Date() object gives the same value
body: <p>I have some code that utilizes the Date object as the name of a file in order to have distinct file names every time but the strange thing is that a new Date object gives off the same <code>toString()</code> for each loop iteration. I mean, the following:</p>
  
  <pre><code>SimpleDateFormat sdf = new SimpleDateFormat("yyyyMMdd_HHmmss");
  String fileName = sdf.format((d = new Date())) + ".jpg";
  
  Log.d("Date", d.toString());
  </code></pre>
  
  <p>is executed in loops.</p>
  
  <p><strong>Side note:</strong> Since this is related to Java API, I haven't tagged the question as that of Android but the OS that executes this code is Android.</p>
  
  <p>AFAIK, <code>new Date()</code> uses <code>System.currentTimeMilis()</code> as the init value, what might be reason for this unusual behavior?</p>