问题
I\'d like to format a duration in seconds using a pattern like H:MM:SS. The current utilities in java are designed to format a time but not a duration.
回答1:
If you're using a version of Java prior to 8... you can use Joda Time and PeriodFormatter. If you've really got a duration (i.e. an elapsed amount of time, with no reference to a calendar system) then you should probably be using Duration for the most part - you can then call toPeriod (specifying whatever PeriodType you want to reflect whether 25 hours becomes 1 day and 1 hour or not, etc) to get a Period which you can format.
If you're using Java 8 or later: I'd normally suggest using java.time.Duration to represent the duration. You can then call getSeconds() or the like to obtain an integer for standard string formatting as per bobince's answer if you need to - although you should be careful of the situation where the duration is negative, as you probably want a single negative sign in the output string. So something like:
public static String formatDuration(Duration duration) {
long seconds = duration.getSeconds();
long absSeconds = Math.abs(seconds);
String positive = String.format(
"%d:%02d:%02d",
absSeconds / 3600,
(absSeconds % 3600) / 60,
absSeconds % 60);
return seconds < 0 ? "-" + positive : positive;
}
Formatting this way is reasonably simple, if annoyingly manual. For parsing it becomes a harder matter in general... You could still use Joda Time even with Java 8 if you want to, of course.
回答2:
If you don't want to drag in libraries, it's simple enough to do yourself using a Formatter, or related shortcut eg. given integer number of seconds s:
String.format("%d:%02d:%02d", s / 3600, (s % 3600) / 60, (s % 60));
回答3:
I use Apache common's DurationFormatUtils like so:
DurationFormatUtils.formatDuration(millis, "**H:mm:ss**", true);
回答4:
long duration = 4 * 60 * 60 * 1000;
SimpleDateFormat sdf = new SimpleDateFormat("HH:mm:ss.SSS", Locale.getDefault());
log.info("Duration: " + sdf.format(new Date(duration - TimeZone.getDefault().getRawOffset())));
回答5:
This will be easier with Java 9. A Duration still isn’t formattable (what I know of), but methods for getting the hours, minutes and seconds are added, which makes the task somewhat more straightforward:
Duration diff = // ...;
String hms = String.format("%d:%02d:%02d",
diff.toHoursPart(),
diff.toMinutesPart(),
diff.toSecondsPart());
回答6:
This might be kind of hacky, but it is a good solution if one is bent on accomplishing this using Java 8's java.time:
import java.time.Duration;
import java.time.LocalDateTime;
import java.time.format.DateTimeFormatter;
import java.time.format.DateTimeFormatterBuilder;
import java.time.temporal.ChronoField;
import java.time.temporal.Temporal;
import java.time.temporal.TemporalAccessor;
import java.time.temporal.TemporalField;
import java.time.temporal.UnsupportedTemporalTypeException;
public class TemporalDuration implements TemporalAccessor {
private static final Temporal BASE_TEMPORAL = LocalDateTime.of(0, 1, 1, 0, 0);
private final Duration duration;
private final Temporal temporal;
public TemporalDuration(Duration duration) {
this.duration = duration;
this.temporal = duration.addTo(BASE_TEMPORAL);
}
@Override
public boolean isSupported(TemporalField field) {
if(!temporal.isSupported(field)) return false;
long value = temporal.getLong(field)-BASE_TEMPORAL.getLong(field);
return value!=0L;
}
@Override
public long getLong(TemporalField field) {
if(!isSupported(field)) throw new UnsupportedTemporalTypeException(new StringBuilder().append(field.toString()).toString());
return temporal.getLong(field)-BASE_TEMPORAL.getLong(field);
}
public Duration getDuration() {
return duration;
}
@Override
public String toString() {
return dtf.format(this);
}
private static final DateTimeFormatter dtf = new DateTimeFormatterBuilder()
.optionalStart()//second
.optionalStart()//minute
.optionalStart()//hour
.optionalStart()//day
.optionalStart()//month
.optionalStart()//year
.appendValue(ChronoField.YEAR).appendLiteral(" Years ").optionalEnd()
.appendValue(ChronoField.MONTH_OF_YEAR).appendLiteral(" Months ").optionalEnd()
.appendValue(ChronoField.DAY_OF_MONTH).appendLiteral(" Days ").optionalEnd()
.appendValue(ChronoField.HOUR_OF_DAY).appendLiteral(" Hours ").optionalEnd()
.appendValue(ChronoField.MINUTE_OF_HOUR).appendLiteral(" Minutes ").optionalEnd()
.appendValue(ChronoField.SECOND_OF_MINUTE).appendLiteral(" Seconds").optionalEnd()
.toFormatter();
}
回答7:
This is going to be one of the new features in java 7
JSR-310
回答8:
Here is one more sample how to format duration. Note that this sample shows both positive and negative duration as positive duration.
import static java.time.temporal.ChronoUnit.DAYS;
import static java.time.temporal.ChronoUnit.HOURS;
import static java.time.temporal.ChronoUnit.MINUTES;
import static java.time.temporal.ChronoUnit.SECONDS;
import java.time.Duration;
public class DurationSample {
public static void main(String[] args) {
//Let's say duration of 2days 3hours 12minutes and 46seconds
Duration d = Duration.ZERO.plus(2, DAYS).plus(3, HOURS).plus(12, MINUTES).plus(46, SECONDS);
//in case of negative duration
if(d.isNegative()) d = d.negated();
//format DAYS HOURS MINUTES SECONDS
System.out.printf("Total duration is %sdays %shrs %smin %ssec.\n", d.toDays(), d.toHours() % 24, d.toMinutes() % 60, d.getSeconds() % 60);
//or format HOURS MINUTES SECONDS
System.out.printf("Or total duration is %shrs %smin %sec.\n", d.toHours(), d.toMinutes() % 60, d.getSeconds() % 60);
//or format MINUTES SECONDS
System.out.printf("Or total duration is %smin %ssec.\n", d.toMinutes(), d.getSeconds() % 60);
//or format SECONDS only
System.out.printf("Or total duration is %ssec.\n", d.getSeconds());
}
}
回答9:
This answer only uses Duration methods and works with Java 8 :
public static String format(Duration d) {
long days = d.toDays();
d = d.minusDays(days);
long hours = d.toHours();
d = d.minusHours(hours);
long minutes = d.toMinutes();
d = d.minusMinutes(minutes);
long seconds = d.getSeconds() ;
return
(days == 0?"":days+" jours,")+
(hours == 0?"":hours+" heures,")+
(minutes == 0?"":minutes+" minutes,")+
(seconds == 0?"":seconds+" secondes,");
}
回答10:
There's a fairly simple and (IMO) elegant approach, at least for durations of less than 24 hours:
DateTimeFormatter.ISO_LOCAL_TIME.format(value.addTo(LocalTime.of(0, 0)))
Formatters need a temporal object to format, so you can create one by adding the duration to a LocalTime of 00:00 (i.e. midnight). This will give you a LocalTime representing the duration from midnight to that time, which is then easy to format in standard HH:mm:ss notation. This has the advantage of not needing an external library, and uses the java.time library to do the calculation, rather than manually calculating the hours, minutes and seconds.
回答11:
This is a working option.
public static String showDuration(LocalTime otherTime){
DateTimeFormatter df = DateTimeFormatter.ISO_LOCAL_TIME;
LocalTime now = LocalTime.now();
System.out.println("now: " + now);
System.out.println("otherTime: " + otherTime);
System.out.println("otherTime: " + otherTime.format(df));
Duration span = Duration.between(otherTime, now);
LocalTime fTime = LocalTime.ofNanoOfDay(span.toNanos());
String output = fTime.format(df);
System.out.println(output);
return output;
}
Call the method with
System.out.println(showDuration(LocalTime.of(9, 30, 0, 0)));
Produces something like:
otherTime: 09:30
otherTime: 09:30:00
11:31:27.463
11:31:27.463
回答12:
How about the following function, which returns either +H:MM:SS or +H:MM:SS.sss
public static String formatInterval(final long interval, boolean millisecs )
{
final long hr = TimeUnit.MILLISECONDS.toHours(interval);
final long min = TimeUnit.MILLISECONDS.toMinutes(interval) %60;
final long sec = TimeUnit.MILLISECONDS.toSeconds(interval) %60;
final long ms = TimeUnit.MILLISECONDS.toMillis(interval) %1000;
if( millisecs ) {
return String.format("%02d:%02d:%02d.%03d", hr, min, sec, ms);
} else {
return String.format("%02d:%02d:%02d", hr, min, sec );
}
}
回答13:
String duration(Temporal from, Temporal to) {
final StringBuilder builder = new StringBuilder();
for (ChronoUnit unit : new ChronoUnit[]{YEARS, MONTHS, WEEKS, DAYS, HOURS, MINUTES, SECONDS}) {
long amount = unit.between(from, to);
if (amount == 0) {
continue;
}
builder.append(' ')
.append(amount)
.append(' ')
.append(unit.name().toLowerCase());
from = from.plus(amount, unit);
}
return builder.toString().trim();
}
回答14:
My library Time4J offers a pattern-based solution (similar to Apache DurationFormatUtils, but more flexible):
Duration<ClockUnit> duration =
Duration.of(-573421, ClockUnit.SECONDS) // input in seconds only
.with(Duration.STD_CLOCK_PERIOD); // performs normalization to h:mm:ss-structure
String fs = Duration.formatter(ClockUnit.class, "+##h:mm:ss").format(duration);
System.out.println(fs); // output => -159:17:01
This code demonstrates the capabilities to handle hour overflow and sign handling, see also the API of duration-formatter based on pattern.
回答15:
In Scala, building up on YourBestBet's solution but simplified:
def prettyDuration(seconds: Long): List[String] = seconds match {
case t if t < 60 => List(s"${t} seconds")
case t if t < 3600 => s"${t / 60} minutes" :: prettyDuration(t % 60)
case t if t < 3600*24 => s"${t / 3600} hours" :: prettyDuration(t % 3600)
case t => s"${t / (3600*24)} days" :: prettyDuration(t % (3600*24))
}
val dur = prettyDuration(12345).mkString(", ") // => 3 hours, 25 minutes, 45 seconds
回答16:
in scala, no library needed:
def prettyDuration(str:List[String],seconds:Long):List[String]={
seconds match {
case t if t < 60 => str:::List(s"${t} seconds")
case t if (t >= 60 && t< 3600 ) => List(s"${t / 60} minutes"):::prettyDuration(str, t%60)
case t if (t >= 3600 && t< 3600*24 ) => List(s"${t / 3600} hours"):::prettyDuration(str, t%3600)
case t if (t>= 3600*24 ) => List(s"${t / (3600*24)} days"):::prettyDuration(str, t%(3600*24))
}
}
val dur = prettyDuration(List.empty[String], 12345).mkString("")
回答17:
I didn't see this one so I thought I'd add it:
Date started=new Date();
SimpleDateFormat format = new SimpleDateFormat("HH:mm:ss");
task
long duration=new Date().getTime()-started.getTime();
System.out.println(format.format(new Date(duration));
It only works for 24 hours but that's what I usually want for duration.
来源：https://stackoverflow.com/questions/266825/how-to-format-a-duration-in-java-e-g-format-hmmss