Can't get messages history in android - XMPP

I've been looking for solution for this problem for more than 3 days now.. :/

I'm making a chat app for android using xmpp - openfire server. I successfully connected and logged into server and now I'm able to chat with Spark from my app..

But now I have to get the recent messages in the one-one chat (history) I read that I have to use a plugin and request the messages.. I used Monitoring Service Plugin and Open Archive Plugin using the following request :

<iq type='get' id='user1'>
      <list xmlns='urn:xmpp:archive'
         with='admin@localhost'>
         <set xmlns='http://ift.tt/1jsKSY9'><max>30</max>
</set></list></iq>

which I sent from android like that :

    Packet packet = new Packet() {
        @Override
        public String toXML() {
            String xExtension = "<iq type='get' id='user1'>"+
            "<list xmlns='urn:xmpp:archive'"+
                    " with='admin@localhost'>"+
            "<set xmlns='http://ift.tt/1jsKSY9'><max>30</max></set></list></iq>";
            return xExtension;
        }
    };
    MainActivity.connection.sendPacket(packet);

And the PackageListener :

    PacketFilter filter = new PacketFilter() {
        public boolean accept(Packet arg0) {
            return true;
        }
    };
    MainActivity.connection.addPacketListener(new PacketListener() {
      public void processPacket(Packet packet) {
          if(packet.getClass() == Message.class ) {
              Message message = (Message) packet;
                final String body = message.getBody();
                final String from = message.getFrom();
                Log.d(TAG, "Got Message : " + body);
          } else {
              Log.d("Chat", "Packet: " + packet.getClass());
              System.out.println("packet details : " + packet.toXML());
          }
      }
    }, filter);

So I get the response as follow :

packet details : <iq id="user1" to="user2@localhost/Smack" type="result"></iq>

Why I don't get the chats although I can see them in Openfire Admin Console..? Any Help Will Be Very Appreciated.. Thanks.