title: Java: Difference between new Properties(...) and new Properties().putAll(...)
body: <p>What's the difference between</p>
  
  <pre><code>    final Properties properties = new Properties(System.getProperties());
  </code></pre>
  
  <p>and</p>
  
  <pre><code>    final Properties properties = new Properties();
      properties.putAll(System.getProperties());
  </code></pre>
  
  <p>I've seen this change as a <a href="https://github.com/jbossas/jboss-as/commit/8c4864b8ebbb689694c4fb128bd6fb44a6ce9a46" rel="noreferrer">fix commit in JBoss AS</a>.</p>