title: System.currentTimeMillis() vs. new Date() vs. Calendar.getInstance().getTime()
body: <p>In Java, what are the performance and resource implications of using</p>
  
  <pre><code>System.currentTimeMillis() 
  </code></pre>
  
  <p>vs. </p>
  
  <pre><code>new Date() 
  </code></pre>
  
  <p>vs. </p>
  
  <pre><code>Calendar.getInstance().getTime()
  </code></pre>
  
  <p>As I understand it, <code>System.currentTimeMillis()</code> is the most efficient. However, in most applications, that long value would need to be converted to a Date or some similar object to do anything meaningful to humans.</p>