Channel channel = getChannel();
//TODO getChannel返回的状态是否包含null需要改进
if (channel == null || ! channel.isConnected()) {
throw new RemotingException(this, "message can not send, because channel is closed . url:" + getUrl());
}
channel.send(message, sent);
}
protected void connect() throws RemotingException {
connectLock.lock();
try {