[ntp:questions] GPL'd Java Implementation of SNTP Client

Adam Buckley adam at adambuckley.net
Sun Jan 18 17:30:35 UTC 2004


Hi Folks,

Here's a(nother?) Java implementation of an NTP client, which I wrote as my
attempt to understand the NTP protocol.  It handles NTP parameters as native
Java types, making it Java-programmer-friendly.

I cannot comment on it's accuracy, because I'm not that clever.  Although I
know that under windows, System.currentTimeMillis() is limited to a
resolution of 10ms as imposed by the windows OS.  This affects the originate
and destination timestamps.  It would be great if someone could provide
feedback on the accuracy (and explain how they did it).

Any corrections/optimisations more than welcome - especially to the number
format conversion algorithms.

Coming soon:

	* hi-res local clock algorithms for Win32 using JNI +
QueryPerformanceCounter
	* Java NTP server

HTH, Adam.


http://adambuckley.net/software/ntp/

NtpMessage.java
Represents an NTP message, exposing members as native java types.  Includes
raw NTP format import/export.

NtpClient.java
NTP client which uses the SNTP algorithm.  Optionally sets local clock
(winXP only at present)


keywords: java ntp client sntp gpl example tutorial




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