@Override
    public void invokeWithCallback(Url url, Object request, InvokeContext invokeContext,
                                   InvokeCallback invokeCallback, int timeoutMillis)
                                                                                    throws RemotingException {
        Connection conn = this.connectionManager.get(url.getUniqueKey());
        if (null == conn) {
            throw new RemotingException("Client address [" + url.getUniqueKey()
                                        + "] not connected yet!");
        }
        this.connectionManager.check(conn);
        this.invokeWithCallback(conn, request, invokeContext, invokeCallback, timeoutMillis);
    }
@see com.alipay.remoting.rpc.RpcRemoting#invokeWithCallback(com.alipay.remoting.Url, java.lang.Object, InvokeContext, com.alipay.remoting.InvokeCallback, int)
src/main/java/com/alipay/remoting/rpc/RpcServerRemoting.java