我想使用System.currentTimeMillis()记录用户在程序中开始某项操作时的时间。当他完成时,我将从start变量中减去当前的System.currentTimeMillis(),并且我希望使用人类可读的格式显示他们所经过的时间,例如“XX小时,XX分钟,XX秒”,甚至“XX分钟,XX秒”,因为它不太可能花费某人一个小时。

最好的方法是什么?


当前回答

手工划分,或者使用SimpleDateFormat API。

long start = System.currentTimeMillis();
// do your work...
long elapsed = System.currentTimeMillis() - start;
DateFormat df = new SimpleDateFormat("HH 'hours', mm 'mins,' ss 'seconds'");
df.setTimeZone(TimeZone.getTimeZone("GMT+0"));
System.out.println(df.format(new Date(elapsed)));

Edit by Bombe:评论中显示,这种方法只适用于较短的持续时间(即少于一天)。

其他回答

我不会为此引入额外的依赖项(毕竟,除法并不那么难),但如果您无论如何都在使用Commons Lang,还有DurationFormatUtils。

用法示例(从这里改编):

import org.apache.commons.lang3.time.DurationFormatUtils

public String getAge(long value) {
    long currentTime = System.currentTimeMillis();
    long age = currentTime - value;
    String ageString = DurationFormatUtils.formatDuration(age, "d") + "d";
    if ("0d".equals(ageString)) {
        ageString = DurationFormatUtils.formatDuration(age, "H") + "h";
        if ("0h".equals(ageString)) {
            ageString = DurationFormatUtils.formatDuration(age, "m") + "m";
            if ("0m".equals(ageString)) {
                ageString = DurationFormatUtils.formatDuration(age, "s") + "s";
                if ("0s".equals(ageString)) {
                    ageString = age + "ms";
                }
            }
        }
    }
    return ageString;
}   

例子:

long lastTime = System.currentTimeMillis() - 2000;
System.out.println("Elapsed time: " + getAge(lastTime)); 

//Output: 2s

注意:从两个LocalDateTime对象中获取millis可以使用:

long age = ChronoUnit.MILLIS.between(initTime, LocalDateTime.now())

使用java.util.concurrent.TimeUnit类:

String.format("%d min, %d sec", 
    TimeUnit.MILLISECONDS.toMinutes(millis),
    TimeUnit.MILLISECONDS.toSeconds(millis) - 
    TimeUnit.MINUTES.toSeconds(TimeUnit.MILLISECONDS.toMinutes(millis))
);

注意:TimeUnit是Java 1.5规范的一部分,但是toMinutes是在Java 1.6中添加的。

为0-9的值添加前导零,只需执行以下操作:

String.format("%02d min, %02d sec", 
    TimeUnit.MILLISECONDS.toMinutes(millis),
    TimeUnit.MILLISECONDS.toSeconds(millis) - 
    TimeUnit.MINUTES.toSeconds(TimeUnit.MILLISECONDS.toMinutes(millis))
);

如果TimeUnit或toMinutes不受支持(例如在API版本9之前的Android上),使用以下公式:

int seconds = (int) (milliseconds / 1000) % 60 ;
int minutes = (int) ((milliseconds / (1000*60)) % 60);
int hours   = (int) ((milliseconds / (1000*60*60)) % 24);
//etc...

这个答案与上面的一些答案相似。然而,我觉得这将是有益的,因为与其他答案不同,这将删除任何额外的逗号或空格,并处理缩写。

/**
 * Converts milliseconds to "x days, x hours, x mins, x secs"
 * 
 * @param millis
 *            The milliseconds
 * @param longFormat
 *            {@code true} to use "seconds" and "minutes" instead of "secs" and "mins"
 * @return A string representing how long in days/hours/minutes/seconds millis is.
 */
public static String millisToString(long millis, boolean longFormat) {
    if (millis < 1000) {
        return String.format("0 %s", longFormat ? "seconds" : "secs");
    }
    String[] units = {
            "day", "hour", longFormat ? "minute" : "min", longFormat ? "second" : "sec"
    };
    long[] times = new long[4];
    times[0] = TimeUnit.DAYS.convert(millis, TimeUnit.MILLISECONDS);
    millis -= TimeUnit.MILLISECONDS.convert(times[0], TimeUnit.DAYS);
    times[1] = TimeUnit.HOURS.convert(millis, TimeUnit.MILLISECONDS);
    millis -= TimeUnit.MILLISECONDS.convert(times[1], TimeUnit.HOURS);
    times[2] = TimeUnit.MINUTES.convert(millis, TimeUnit.MILLISECONDS);
    millis -= TimeUnit.MILLISECONDS.convert(times[2], TimeUnit.MINUTES);
    times[3] = TimeUnit.SECONDS.convert(millis, TimeUnit.MILLISECONDS);
    StringBuilder s = new StringBuilder();
    for (int i = 0; i < 4; i++) {
        if (times[i] > 0) {
            s.append(String.format("%d %s%s, ", times[i], units[i], times[i] == 1 ? "" : "s"));
        }
    }
    return s.toString().substring(0, s.length() - 2);
}

/**
 * Converts milliseconds to "x days, x hours, x mins, x secs"
 * 
 * @param millis
 *            The milliseconds
 * @return A string representing how long in days/hours/mins/secs millis is.
 */
public static String millisToString(long millis) {
    return millisToString(millis, false);
}

如果你知道时间差将小于一个小时,那么你可以使用以下代码:

    Calendar c1 = Calendar.getInstance();
    Calendar c2 = Calendar.getInstance();

    c2.add(Calendar.MINUTE, 51);

    long diff = c2.getTimeInMillis() - c1.getTimeInMillis();

    c2.set(Calendar.MINUTE, 0);
    c2.set(Calendar.HOUR, 0);
    c2.set(Calendar.SECOND, 0);

    DateFormat df = new SimpleDateFormat("mm:ss");
    long diff1 = c2.getTimeInMillis() + diff;
    System.out.println(df.format(new Date(diff1)));

结果是:51:00

我的简单计算是:

String millisecToTime(int millisec) {
    int sec = millisec/1000;
    int second = sec % 60;
    int minute = sec / 60;
    if (minute >= 60) {
        int hour = minute / 60;
        minute %= 60;
        return hour + ":" + (minute < 10 ? "0" + minute : minute) + ":" + (second < 10 ? "0" + second : second);
    }
    return minute + ":" + (second < 10 ? "0" + second : second);
}

快乐编码:)