org.apache.commons.net包,封装多种协议
//通过commons-net-3.0.1.jar包获取网络时间
try {
NTPUDPClient timeClient = new NTPUDPClient();
String timeServerUrl = "time-a.nist.gov";
InetAddress timeServerAddress = InetAddress.getByName(timeServerUrl);
TimeInfo timeInfo = timeClient.getTime(timeServerAddress);
TimeStamp timeStamp = timeInfo.getMessage().getTransmitTimeStamp();
DateFormat dateFormat = new SimpleDateFormat("yyyy-MM-dd hh:mm:ss");
System.out.println(dateFormat.format(timeStamp.getDate()));
} catch (UnknownHostException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
}
