从纳秒级获取人类可读时间

Question

我正在尝试使用 System.nanoTime()

实现 ETA 功能

startTime = System.nanoTime()
Long elapsedTime = System.nanoTime() - startTime;
Long allTimeForDownloading = (elapsedTime * allBytes / downloadedBytes);

Long remainingTime = allTimeForDownloading - elapsedTime;

但我不知道如何获得纳秒的人类可读形式；例如：1d 1h、36s 和 3m 50s.

我该怎么做？

Answer 1

这是我的旧代码，你也可以把它转换成天数。

  private String calculateDifference(long timeInMillis) {
    String hr = "";
    String mn = "";
    long seconds = (int) ((timeInMillis) % 60);
    long minutes = (int) ((timeInMillis / (60)) % 60);
    long hours = (int) ((timeInMillis / (60 * 60)) % 24);

    if (hours < 10) {
        hr = "0" + hours;
    }
    if (minutes < 10) {
        mn = "0" + minutes;
    }
    textView.setText(Html.fromHtml("<i><small;text-align: justify;><font color=\"#000\">" + "Total shift time: " + "</font></small; text-align: justify;></i>" + "<font color=\"#47a842\">" + hr + "h " + mn + "m " + seconds + "s" + "</font>"));
    return hours + ":" + minutes + ":" + seconds;
}
 }

Answer 2

如果 remainingTime 在纳秒内，只需计算并将值附加到 StringBuilder:

long remainingTime = 5023023402000L;
StringBuilder sb = new StringBuilder();
long seconds = remainingTime / 1000000000;
long days = seconds / (3600 * 24);
append(sb, days, "d");
seconds -= (days * 3600 * 24);
long hours = seconds / 3600;
append(sb, hours, "h");
seconds -= (hours * 3600);
long minutes = seconds / 60;
append(sb, minutes, "m");
seconds -= (minutes * 60);
append(sb, seconds, "s");
long nanos = remainingTime % 1000000000;
append(sb, nanos, "ns");

System.out.println(sb.toString());

// auxiliary method
public void append(StringBuilder sb, long value, String text) {
    if (value > 0) {
        if (sb.length() > 0) {
            sb.append(" ");
        }
        sb.append(value).append(text);
    }
}

上面的输出是：

1h 23m 43s 23402000ns

（1 小时 23 分 43 秒 23402000 纳秒）。

Answer 3

我会说这两个答案都是正确的，但无论如何这里是一个接受纳米时间和 returns 人类可读字符串的函数的更短版本。

private String getReadableTime(Long nanos){

    long tempSec    = nanos/(1000*1000*1000);
    long sec        = tempSec % 60;
    long min        = (tempSec /60) % 60;
    long hour       = (tempSec /(60*60)) % 24;
    long day        = (tempSec / (24*60*60)) % 24;
    
    return String.format("%dd %dh %dm %ds", day,hour,min,sec);

}

为了获得最大的准确性，您可以使用浮点除法和向上舍入来代替整数除法。

Answer 4

这是我的建议。它基于 TimeUnit.values() 中的单位从最小（纳秒）到最长（天）排序的事实。

    private static String getHumanReadableTime(long nanos) {
        TimeUnit unitToPrint = null;
        String result = "";
        long rest = nanos;
        for(TimeUnit t: TimeUnit.values()) {
            if (unitToPrint == null) {
                unitToPrint = t;
                continue;
            }
            // convert 1 of "t" to "unitToPrint", to get the conversion factor
            long factor = unitToPrint.convert(1, t);
            long value = rest % factor;
            rest /= factor;

            result = value + " " + unitToPrint + " " + result;

            unitToPrint = t;
            if (rest == 0) {
                break;
            }
        }
        if (rest != 0) {
            result = rest + " " + unitToPrint + " " + result;
        }

        return result.trim();
    }

getHumanReadableTime(139543185092L) 的输出将是

2 MINUTES 19 SECONDS 543 MILLISECONDS 185 MICROSECONDS 92 NANOSECONDS

Answer 5

java.time

您可以使用 java.time.Duration which is modelled on ISO-8601 standards and was introduced with Java-8 as part of JSR-310 implementation。 Java-9 引入了一些更方便的方法。

演示：

import java.time.Duration;

public class Main {
    public static void main(String[] args) {
        long elapsedTime = 12345678987654321L;

        Duration duration = Duration.ofNanos(elapsedTime);
        // Default format
        System.out.println(duration);

        // Custom format
        // ####################################Java-8####################################
        String formattedElapsedTime = String.format(
                "%02d Day %02d Hour %02d Minute %02d Second %d Millisecond %d Nanosecond", duration.toDays(),
                duration.toHours() % 24, duration.toMinutes() % 60, duration.toSeconds() % 60,
                duration.toMillis() % 1000, duration.toNanos() % 1000000L);
        System.out.println(formattedElapsedTime);
        // ##############################################################################

        // ####################################Java-9####################################
        formattedElapsedTime = String.format("%02d Day %02d Hour %02d Minute %02d Second %d Millisecond %d Nanosecond",
                duration.toDaysPart(), duration.toHoursPart(), duration.toMinutesPart(), duration.toSecondsPart(),
                duration.toMillisPart(), duration.toNanosPart() % 1000000L);
        System.out.println(formattedElapsedTime);
        // ##############################################################################
    }
}

输出：

PT3429H21M18.987654321S
142 Day 21 Hour 21 Minute 18 Second 987 Millisecond 654321 Nanosecond
142 Day 21 Hour 21 Minute 18 Second 987 Millisecond 654321 Nanosecond

从 Trail: Date Time.

了解有关现代日期时间 API 的更多信息

出于任何原因，如果您必须坚持使用 Java 6 或 Java 7，您可以使用 ThreeTen-Backport，它向后移植了大部分 java.time Java 6 和 7 的功能。
如果您正在为 Android 项目工作，并且您的 Android API 水平仍然不符合 Java-8，请检查 Java 8+ APIs available through desugaring and 。

从纳秒级获取人类可读时间

Get Human readable time from nanoseconds

java

time

android

duration

datetime-conversion

java.time