/**
* 过滤得到Register信息包</br>
* 建立一个过滤包类-->发送空register-->收register包-->取得attribs,form
* */
private void getAttribs(){
PacketFilter filter = new AndFilter(new PacketTypeFilter(IQ.class),new IQTypeFilter(IQ.Type.RESULT));
PacketCollector regCollector = conn.createPacketCollector(filter);
//发送空的registration
conn.sendPacket(new Registration());
//等待包
Packet recvPacket = regCollector.nextResult();