timing in Java

[Ana Mihailescu]

I have the following problem:
I need a clock, which first to take the value of the system time,
and then to be increased every second; I tryed to do this with a thread, but after a couple of minutes, there are differences between my clock and the system clock; how can I do to eliminate this difference ?
the run() method has the following code
public void run()
{

Calendar c= Calendar.getInstance();
while (true) {
try {

Thread.sleep(1000);
c.add(Calendar.SECOND,1);

jLabel1.setText(c.getTime().toString());
jLabel2.setText(Calendar.getInstance().getTime ().toString());
} catch(InterruptedException interruptedexception){}
}
}

[Frank Carver]

I don't really understand why you can't just read the system time each time your thread wakes up. Why would you need to keep a second copy of the time when there is already one in the system ?

[Ana Mihailescu]

if fact, we have an applet which retrieve the time of a database
and after a while uses it; I don't want to connect to the database again, and I want to continue increasing the time from the database in the applet; but it seems that after a while some delays occur ...

[Veena Rani]

when you say Thread.sleep(1000) you can never be certain that the
thread will start executing exactly after 1000 ms.
thats why there is a delay after some time.
Veena Rani
[This message has been edited by veena rani (edited May 08, 2001).]

[Marius Holm]

I think you can read system time from the applet, if that helps.

[Ana Mihailescu]

Veena ,
I think you are right, I will try to do like this:
when I read the time from the database I make the difference between that time and the system time, and then , when I need again the time of the database, I will use this number and the system time.
Thanx for participating !
Ana