How to find out the Real Geographical Time, as in my application I want to attach the real time with my application.
So that if the user changes the time in his device then I should get only the real prevailing time - NOT THE DEVICE TIME
My question is much confusing but try to understand in a simple language -
I dont want DEVICE TIME, I want REAL PREVAILING TIME at any instant
You need to use the NTP (Network Time Protocol) protocol:
Here is some code I found somewhere else... and I am using it. This uses the Apache Commons library, which can be installed using Gradle (adding a dependency on commons-net:commons-net:3.6)
If you need a list of time servers, check: http://tf.nist.gov/service/time-servers.html
Here is some Java Code for you to use:
public class TimeLookup {
public static final String TIME_SERVER = "time-a.nist.gov";
public static void main(String[] args) throws Exception {
NTPUDPClient timeClient = new NTPUDPClient();
InetAddress inetAddress = InetAddress.getByName(TIME_SERVER);
TimeInfo timeInfo = timeClient.getTime(inetAddress);
long returnTime = timeInfo.getReturnTime();
Date time = new Date(returnTime);
System.out.println("Time from " + TIME_SERVER + ": " + time);
}
}
Note the Android code must run on the background thread and include gradle dependency:
implementation 'commons-net:commons-net:3.6'
There is no Android API to get you such a time. The user can always change the device time, nothing you can do about that.
Your best bet would be to run a server with a webservice, from which you can get the time. Since you control the server, you can try to ensure it returns the correct time.
