请求包头类型为RegisterBrokerRequestHeader包括的字段

private RegisterBrokerResult registerBroker(
    final String namesrvAddr,
    final boolean oneway,
    final int timeoutMills,
    final RegisterBrokerRequestHeader requestHeader,
    final byte[] body
) throws RemotingCommandException, MQBrokerException, RemotingConnectException, RemotingSendRequestException, RemotingTimeoutException,
InterruptedException {
    //创建请求指令，需要注意RequestCode.REGISTER_BROKER，nameserver端的网络处理器会根据requestCode进行相应的业务处理
    RemotingCommand request = RemotingCommand.createRequestCommand(RequestCode.REGISTER_BROKER, requestHeader);
    request.setBody(body);
  //基于netty进行网络传输
    if (oneway) {
        //如果是单向调用，没有返回值，不返回nameserver返回结果
        try {
            this.remotingClient.invokeOneway(namesrvAddr, request, timeoutMills);
        } catch (RemotingTooMuchRequestException e) {
            // Ignore
        }
        return null;
    }
  //异步调用向nameserver发起注册，获取nameserver的返回信息
    RemotingCommand response = this.remotingClient.invokeSync(namesrvAddr, request, timeoutMills);
    assert response != null;
    switch (response.getCode()) {
        case ResponseCode.SUCCESS: {
            //获取返回的reponseHeader
            RegisterBrokerResponseHeader responseHeader =
                (RegisterBrokerResponseHeader) response.decodeCommandCustomHeader(RegisterBrokerResponseHeader.class);
            //重新封装返回结果，更新masterAddr和haServerAddr
            RegisterBrokerResult result = new RegisterBrokerResult();
            result.setMasterAddr(responseHeader.getMasterAddr());
            result.setHaServerAddr(responseHeader.getHaServerAddr());
            if (response.getBody() != null) {
                result.setKvTable(KVTable.decode(response.getBody(), KVTable.class));
            }
            return result;
        }
        default:
            break;
    }
​
    throw new MQBrokerException(response.getCode(), response.getRemark(), requestHeader == null ? null : requestHeader.getBrokerAddr());
}