Sure you can

RosterGroup#addEntry(RosterEntry entry)

if you want to remove someone from a group then there is also

RosterGroup#removeEntry(RosterEntry entry);

hth

Jon

not as far as I''m aware of. Roster#removeEntry(RosterEntry entry) would remove the contact from your Roster but RosterGroup#removeEntry(RosterEntry entry) would simply remove that contact from the specified group.

As far as I know they wont be called, but I could be wrong.

To update your gui with the correct display after you have added/removed an entry from a group you could simply call a method to redraw your roster. As long as your roster drawing code included pulling groups and their members then it should show the updated list

So something like this could be called after you have either added or deleted a RosterEntry from a RosterGroup.

Roster roster;
// Get all RosterGroups from your Roster
Iterator groupsIter = roster.getGroups();

// Loop through each group and display its members
while(groupsIter.hasNext()) {
    RosterGroup rosterGroup = (RosterGroup)groupsIter.next();
    System.out.println("Group: " + rosterGroup.getName());

    // Get the members of each group.
    Iterator groupEntries = rosterGroup.getEntries();
    while(groupEntries.hasNext()) {
        RosterEntry rosterEntry = (RosterEntry)groupEntries.next();
        System.out.println("Contact: " + rosterEntry.getUser()):
    }

}