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?
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
对于正确的字符串(“1小时,3秒”,“3分钟”,而不是“0小时,0分钟,3秒”),我写这样的代码:
int seconds = (int)(millis / 1000) % 60 ;
int minutes = (int)((millis / (1000*60)) % 60);
int hours = (int)((millis / (1000*60*60)) % 24);
int days = (int)((millis / (1000*60*60*24)) % 365);
int years = (int)(millis / 1000*60*60*24*365);
ArrayList<String> timeArray = new ArrayList<String>();
if(years > 0)
timeArray.add(String.valueOf(years) + "y");
if(days > 0)
timeArray.add(String.valueOf(days) + "d");
if(hours>0)
timeArray.add(String.valueOf(hours) + "h");
if(minutes>0)
timeArray.add(String.valueOf(minutes) + "min");
if(seconds>0)
timeArray.add(String.valueOf(seconds) + "sec");
String time = "";
for (int i = 0; i < timeArray.size(); i++)
{
time = time + timeArray.get(i);
if (i != timeArray.size() - 1)
time = time + ", ";
}
if (time == "")
time = "0 sec";
其他回答
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
首先,System.currentTimeMillis()和Instant.now()对于计时来说并不理想。它们都报告了挂钟时间,而计算机并不能准确地知道这个时间,而且它可能会不规律地移动,例如,如果NTP守护进程更正了系统时间,就会往回走。如果计时发生在一台机器上,那么应该使用System.nanoTime()。
其次,从Java 8开始,Java .time. duration是表示持续时间的最佳方式:
long start = System.nanoTime();
// do things...
long end = System.nanoTime();
Duration duration = Duration.ofNanos(end - start);
System.out.println(duration); // Prints "PT18M19.511627776S"
System.out.printf("%d Hours %d Minutes %d Seconds%n",
duration.toHours(), duration.toMinutes() % 60, duration.getSeconds() % 60);
// prints "0 Hours 18 Minutes 19 Seconds"
基于@siddhadev的回答,我写了一个将毫秒转换为格式化字符串的函数:
/**
* Convert a millisecond duration to a string format
*
* @param millis A duration to convert to a string form
* @return A string of the form "X Days Y Hours Z Minutes A Seconds".
*/
public static String getDurationBreakdown(long millis) {
if(millis < 0) {
throw new IllegalArgumentException("Duration must be greater than zero!");
}
long days = TimeUnit.MILLISECONDS.toDays(millis);
millis -= TimeUnit.DAYS.toMillis(days);
long hours = TimeUnit.MILLISECONDS.toHours(millis);
millis -= TimeUnit.HOURS.toMillis(hours);
long minutes = TimeUnit.MILLISECONDS.toMinutes(millis);
millis -= TimeUnit.MINUTES.toMillis(minutes);
long seconds = TimeUnit.MILLISECONDS.toSeconds(millis);
StringBuilder sb = new StringBuilder(64);
sb.append(days);
sb.append(" Days ");
sb.append(hours);
sb.append(" Hours ");
sb.append(minutes);
sb.append(" Minutes ");
sb.append(seconds);
sb.append(" Seconds");
return(sb.toString());
}
乔达时间
使用Joda-Time:
DateTime startTime = new DateTime();
// do something
DateTime endTime = new DateTime();
Duration duration = new Duration(startTime, endTime);
Period period = duration.toPeriod().normalizedStandard(PeriodType.time());
System.out.println(PeriodFormat.getDefault().print(period));