import java.util.*; import java.io.*; public class TimeToMilli{ public String millisecondsToString(long time){ int milliseconds = (int)(time % 1000); int seconds = (int)((time/1000) % 60); int minutes = (int)((time/60000) % 60); int hours = (int)((time/3600000) % 24); String millisecondsStr = (milliseconds<10 ? "00" : (milliseconds<100 ? "0" : ""))+milliseconds; String secondsStr = (seconds<10 ? "0" : "")+seconds; String minutesStr = (minutes<10 ? "0" : "")+minutes; String hoursStr = (hours<10 ? "0" : "")+hours; return new String(hoursStr+":"+minutesStr+":"+secondsStr+"."+millisecondsStr); } public static void main(String[] args){ long time = 200000000; TimeToStr ts = new TimeToStr(); System.out.println(ts.millisecondsToString(time)); } }