public boolean alreadyJoinedWithThisNick(@Nonnull final JID realJID, @Nonnull final String nickname)
    {
        return occupants.stream()
            .anyMatch(occupant -> occupant.getUserAddress().equals(realJID) && occupant.getNickname().equalsIgnoreCase(nickname));
    }
Sends the room subject to a user that just joined the room.
xmppserver/src/main/java/org/jivesoftware/openfire/muc/MUCRoom.java