如何用Java从Internet时间服务器准确获取时间？

import javax.time.ntp.NTPUDPClient;
import javax.time.ntp.TimeInfo;
import java.net.InetAddress;
import java.util.Date;

public class TimeSync {

    public static void main(String[] args) throws Exception {
        // Specify the time server hostname
        String TIME_SERVER = "in.pool.ntp.org";

        // Create an NTP UDP client
        NTPUDPClient timeClient = new NTPUDPClient();

        // Get the server's IP address
        InetAddress inetAddress = InetAddress.getByName(TIME_SERVER);

        // Retrieve time information from the server
        TimeInfo timeInfo = timeClient.getTime(inetAddress);

        // Get the time at which the packet was sent by the server
        long returnTime = timeInfo.getMessage().getTransmitTimeStamp().getTime();

        // Convert the epoch time to a Date object
        Date time = new Date(returnTime);

        // Print the synchronized time
        System.out.println("Current GMT time: " + time);
    }
}