title: Get user are online or not, by using QuickBlox
body: <p>I'm using QuickBlox as BaaS. I would like to try getting user status. Are they online or not ?
  Found below useful question and I used Roster.
  <a href="https://stackoverflow.com/questions/4665948/can-i-get-online-users-in-my-friend-list-via-smack">Can I get online users in my friend list via Smack?</a></p>
  
  <p>But When I retrieve by implementing following, get null entries. </p>
  
  <pre><code>Roster roster = xmppConnection.getRoster();
  Collection&lt;RosterEntry&gt; entries = roster.getEntries();
  Presence presence;
  
      for(RosterEntry entry : entries) {
          presence = roster.getPresence(entry.getUser());
  
          System.out.println(entry.getUser());
          System.out.println(presence.getType().name());
          System.out.println(presence.getStatus());
      }
  </code></pre>