How can i get event_name from listener

[liangyuanpeng]

public class HelloListener implements DataListener {
    @Override
    public void onData(SocketIOClient client, Object data, AckRequest ackSender) throws Exception {
        log.info("data:{}",data);
    }
}

In my case, i just want to know who send data to me and hope all the data will arrive here. remind me if i missed some doc. please!