Thanks a lot Connor, I have just had a look to DiscussionHistory mechanisms and, if I have understood it well, I would only get messages (history) when I join the MUC.
Of course, I can store these messages to be able to return them for user when he wants, but that is not very satisfying considering the SMS/Wap environment.
Indeed, after joining a MUC or GroupChat, I would like to be able to send messages (that is possible with sendMessage(String)) and get X (for example 3) latest messages posted in MUC or GroupChat at particular time without a Listener (I do not know if it is possible).
As I did not find it with Smack, I was wondering how to do this (if it could be implemented with XMPP). So, is there another way to solve my problem that could suits me more than Connor’'s solution (which can do the job but which is not perfect)?