Get Human readable time from nanoseconds

问题:

I am trying to implement an ETA feature Using System.nanoTime()

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

Long remainingTime = allTimeForDownloading - elapsedTime;

But I cannot figure how to get a human readable form of the nanoseconds; for example: 1d 1h, 36s and 3m 50s.

How can I do this?

回答1:

If remainingTime is in nanoseconds, just do the math and append the values to a 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);
    }
}

The output for the above is:

1h 23m 43s 23402000ns

(1 hour, 23 minutes, 43 seconds and 23402000 nanoseconds).

回答2:

I would say both of these answers are correct, but anyways here is a little shorter version of a function that accepts nano time and returns human-readable String.

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);

}

For maximum accuracy, instead of integer division, you can use float division and round up.

回答3:

It is my old code, you can convert it to days also.

  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;
}
 }