Answer:
import javax.swing.*;
import java.awt.*;
import java.text.*;
import java.util.*;
public class DigitalWatch implements Runnable{
JFrame f;
Thread t=null;
int hours=0, minutes=0, seconds=0;
String timeString = "";
JButton b;
DigitalWatch(){
f=new JFrame();
t = new Thread(this);
t.start();
b=new JButton();
b.setBounds(100,100,100,50);
f.add(b);
f.setSize(300,400);
f.setLayout(null);
f.setVisible(true);
}
public void run() {
try {
while (true) {
Calendar cal = Calendar.getInstance();
hours = cal.get( Calendar.HOUR_OF_DAY );
if ( hours > 12 ) hours -= 12;
minutes = cal.get( Calendar.MINUTE );
seconds = cal.get( Calendar.SECOND );
SimpleDateFormat formatter = new SimpleDateFormat("hh:mm:ss");
Date date = cal.getTime();
timeString = formatter.format( date );
printTime();
t.sleep( 1000 ); // interval given in milliseconds
}
}
catch (Exception e) { }
}
public void printTime(){
b.setText(timeString);
}
public static void main(String[] args) {
new DigitalWatch();
}
}
Explanation:
