直接上代码，看注释应该很好理解，只是提供一种思路，不对的请大神指正：
public class PresenceService extends Service { private _ConnectionControl cc = _ConnectionControl.getCC();//单例模式 保存了当前的链接 @Override public IBinder onBind(Intent arg0) { return null; } @Override public void onCreate() { super.onCreate(); } @Override public void onDestroy() { super.onDestroy(); Log.i("onDestroy", "PresenceService -- onDestroy"); } @Override public int onStartCommand(Intent intent, int flags, int startId) { Log.i("Presence", "PresenceService-----" + (cc.connection == null)); if (cc.connection != null && cc.connection.isConnected() && cc.connection.isAuthenticated()) {//已经认证的情况下，才能正确收到Presence包（也就是登陆） final String loginuser = cc.connection.getUser().substring(0, cc.connection.getUser().lastIndexOf("@")); //理解为条件过滤器 过滤出Presence包 PacketFilter filter = new AndFilter(new PacketTypeFilter( Presence.class)); PacketListener listener = new PacketListener() { @Override public void processPacket(Packet packet) { Log.i("Presence", "PresenceService------" + packet.toXML()); //看API可知道 Presence是Packet的子类 if (packet instanceof Presence) { Log.i("Presence", packet.toXML()); Presence presence = (Presence) packet; //Presence还有很多方法，可查看API String from = presence.getFrom();//发送方 String to = presence.getTo();//接收方 //Presence.Type有7中状态 if (presence.getType().equals(Presence.Type.subscribe)) {//好友申请 } else if (presence.getType().equals( Presence.Type.subscribed)) {//同意添加好友 } else if (presence.getType().equals( Presence.Type.unsubscribe)) {//拒绝添加好友 和 删除好友 } else if (presence.getType().equals( Presence.Type.unsubscribed)) {//这个我没用到 } else if (presence.getType().equals( Presence.Type.unavailable)) {//好友下线 要更新好友列表，可以在这收到包后，发广播到指定页面 更新列表 } else {//好友上线 } } } }; cc.connection.addPacketListener(listener, filter); } return super.onStartCommand(intent, flags, startId); }}