Java smack / Android asmack RosterListener

Question

I've been searching alot. but couldn't find anything. I need to refresh state of the contacts with rosterlistener. (offline/online). WHen creating roster i do:

Presence presence = roster.getPresence(r.getUser());
                if(presence.isAvailable()){
                    userstatus.add("online");
                }else{
                    userstatus.add("offline");
                }

userstatus is a vector string, then i make a string array from it. In my main program i just check this stirng array for the offline or online. But what to do if user goes offline/online. WHere exactly i must put the listener and how exactly to use it?

Answer 1

You implement a RosterListener and make use of the presenceChanged() method. Here's sample code exactly as it appears in the Smack documentation .

Roster roster = con.getRoster();
roster.addRosterListener(new RosterListener() {
    // Ignored events public void entriesAdded(Collection<String> addresses) {}
    public void entriesDeleted(Collection<String> addresses) {}
    public void entriesUpdated(Collection<String> addresses) {}
    public void presenceChanged(Presence presence) {
        System.out.println("Presence changed: " + presence.getFrom() + " " + presence);
    }
});

Note that the JavaDoc suggests not using the presence received in the change event but checking for the best presence available each time:

To get the current "best presence" for a user after the presence update, query the roster:

String user = presence.getFrom();
Presence bestPresence = roster.getPresence(user);

That will return the presence value for the user with the highest priority and availability.