android – 我可以通过Smack在我的朋友列表中获取在线用户吗？

Roster roster = xmppConnection.getRoster();
Collection<RosterEntry> 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());
}