how to convert seconds into hhmmss
Using the old java date api (not recommended, see comments):
int sec = .... //
Date d = new Date(sec * 1000L);
SimpleDateFormat df = new SimpleDateFormat("HH:mm:ss"); // HH for 0-23
df.setTimeZone(TimeZone.getTimeZone("GMT"));
String time = df.format(d);
See also SimpleDateFormat
.
Note: as per comments, if the number of seconds exceeds the number of seconds in a day (86400) that won't work as expected. In that case a different approach must be taken.
EDIT: If you're using JDK 8 you can write:
int sec = ...
Duration duration = Duration.ofSeconds(sec);
This duration object better represents what you're talking about. I am trying to find out how to format it as you want to but I have had no luck so far.
EDIT 2: prior to JDK 8 you can use the Joda API:
int sec = ...
Period period = new Period(sec * 1000L);
String time = PeriodFormat.getDefault().print(period); // you can customize the format if this one doesn't cut it
That's probably the most elegant solution. See also this.
EDIT 3: As per comments, I explicitly added the time zone.
Just in case you're looking to write your own algorithm for this:
Let's say we have 1000 seconds.
We know that there're 3600 seconds in an hour, so when we format this time as hh:mm:ss, the hh field will be 00. Now let's say we're given a time of 3700 seconds. This time interval is slightly larger than 1 hour, so we know that the hh field will show 01.
So to calculate the number for the hh field, simply divide the provided seconds amount by 3600.
int hours = seconds / 3600
Note that when we have a seconds amount greater than 3600, the result is truncated, so we're left with an integer amount for the hours.
Moving on to the mm field. Again, let's assume we're given a time interval of 3700 seconds. We already know that 3700 seconds is slightly more than 1 hour - we've stored the number of hours in the hour
field. To calculate the number of minutes, we'll subtract the hours times 3600 from the provided seconds input:
int minutes = (seconds - hours * 3600) / 60
So if we have a provided time of 3700 seconds, the above code translates to (3700 - 3600) / 60 - we divide by 60 because we want to convert from seconds to minutes.
Finally, the ss field. We use a similar technique as above to calculate the number of seconds.
int seconds = (seconds - hours * 3600) - minutes * 60
public static String formatSeconds(int timeInSeconds)
{
int hours = timeInSeconds / 3600;
int secondsLeft = timeInSeconds - hours * 3600;
int minutes = secondsLeft / 60;
int seconds = secondsLeft - minutes * 60;
String formattedTime = "";
if (hours < 10)
formattedTime += "0";
formattedTime += hours + ":";
if (minutes < 10)
formattedTime += "0";
formattedTime += minutes + ":";
if (seconds < 10)
formattedTime += "0";
formattedTime += seconds ;
return formattedTime;
}
public static void formatSeconds(Integer result){
System.out.print(String.format("%02d",result/3600)+":");
System.out.print(String.format("%02d",result/60%60)+":");
System.out.println(String.format("%02d",result%60));
}