protected CommandFactory getCommandFactory(ProtocolCode protocolCode) {
        if (protocolCode == null) {
            return getCommandFactory();
        }
        Protocol protocol = ProtocolManager.getProtocol(protocolCode);
        if (protocol == null) {
            return getCommandFactory();
        }
        return protocol.getCommandFactory();
    }
Create invoke future with {@link InvokeContext}.
@param conn
@param request
@param invokeContext
@param invokeCallback
@return
src/main/java/com/alipay/remoting/BaseRemoting.java