public void changeSubject(final String subject) throws XMPPException {
Message message = new Message(room, Message.Type.groupchat);
message.setSubject(subject);
// Wait for an error or confirmation message back from the server.
PacketFilter responseFilter =
new AndFilter(
new FromMatchesFilter(room),
new PacketTypeFilter(Message.class));
responseFilter = new AndFilter(responseFilter, new PacketFilter() {
public boolean accept(Packet packet) {
Message msg = (Message) packet;
return subject.equals(msg.getSubject());
}
});