克里斯蒂安&x2019；s算法java同步时间错误

我正在用java开发一个套接字服务器/客户端。客户机发送请求请求时间。服务器发送响应。同步客户端时间是使用Cristian算法计算的。Tclient=Tserver+（T1-T0）/2

服务器代码：

 @Override
public void run() {
    String received;
    while (true) {
        try {

            // Ask user what he wants
            dos.writeUTF("Type 't' to get time..\n" +
                    "Type exit to terminate connection.");

            // receive the answer from client
            received = dis.readUTF();

            if (received.equals("exit")) {
                System.out.println("Client " + this.s + " sends exit...");
                System.out.println("Closing this connection.");
                this.s.close();
                System.out.println("Connection closed");
                break;
            } else if (received.equals("t")) {

                long currentTimeMillis = Instant.now().toEpochMilli();
                dos.writeLong(currentTimeMillis);

                String ip=(((InetSocketAddress) s.getRemoteSocketAddress()).getAddress()).toString().replace("/","");
                insert(ip, currentTimeMillis);


            } else {

                dos.writeUTF("Invalid input");

            }

        } catch (IOException e) {
            e.printStackTrace();
        }
    }
}

客户端代码：

 try (Scanner scn = new Scanner(System.in);
         Socket s = new Socket(InetAddress.getByName("localhost"), 5068);
         DataInputStream dis = new DataInputStream(s.getInputStream());
         DataOutputStream dos = new DataOutputStream(s.getOutputStream())) {

        // the following loop performs the exchange of
        // information between client and client handler
        while (true) {

            System.out.println(dis.readUTF());
            String tosend = scn.nextLine();

            dos.writeUTF(tosend);
            //Time when the request is sent
            Instant requestTimeInstant = Instant.now();
            System.out.println("Time  at which the request is sent " + getFormattedTime(requestTimeInstant.toEpochMilli()));


            // If client sends exit,close this connection
            // and then break from the while loop
            if (tosend.equals("exit")) {
                System.out.println("Closing this connection : " + s);
                s.close();
                System.out.println("Connection closed");
                break;
            } else if(tosend.equals("t")){

                // printing date or time as requested by client
                long serverTime = dis.readLong();
                Instant responseTimeInstant = Instant.now();


                System.out.println("Time  at  which  the  response  is  received Instant " + getFormattedTime(responseTimeInstant.toEpochMilli()));


                //Apply christian' algorithm Tclient = Tserver + (T1 - T0)/2 where
                // T0   time  at which the request is sent
                //and T1 time  at  which  the  response  is  received
                long deltaMill = Duration.between(requestTimeInstant,responseTimeInstant).toMillis();
                long halfDeltaTime = deltaMill / 2;

                System.out.println(deltaMill);

                System.out.println("Added time to serverTime " + halfDeltaTime + " Milliseconds");


                long clientTimeMills = serverTime + halfDeltaTime;
                System.out.println("Server time " + getFormattedTime(serverTime));
                System.out.println("client time " +  getFormattedTime(clientTimeMills));

                System.out.println("Sync time error " +(responseTimeInstant.toEpochMilli() -clientTimeMills) + " Milliseconds");

            }
        }

    } catch (Exception e) {
        e.printStackTrace();
    }

我实际上有一个不连贯的输出（仅在请求的第一个响应中，存在同步时间错误），我无法找出原因：