英文:
Java How to get the percentage between 2 datetimes
问题
private void getpercentage(String dateTimeStart, String dateTimeExpiration) {
LocalDateTime start = LocalDateTime.parse(dateTimeStart.replace(" ", "T"));
LocalDateTime end = LocalDateTime.parse(dateTimeExpiration.replace(" ", "T"));
String start_date = start.toString().replace("T", " ");
String end_date = end.toString().replace("T", " ");
double differenceInSeconds = Duration.between(start, end).getSeconds();
double percentage = (differenceInSeconds / 86400) * 100; // Assuming a day has 86400 seconds
String p = Math.round(percentage) + "%";
Log.d("type", "Date parsed: " + p);
}
英文:
I want get the percentage between two DateTimes so i can use a progress bar.
I have the following code i'm passing in two datetimes and doing the sum but i am getting an error.
private void getpercentage(String dateTimeStart, String dateTimeExpiration) {
LocalDateTime start = LocalDateTime.parse(dateTimeStart.replace( " " , "T" ) );
LocalDateTime end = LocalDateTime.parse(dateTimeExpiration.replace( " " , "T" ) );
String start_date = start.toString().replace( "T", " " );
String end_date = end.toString().replace( "T", " " );
String p = Math.round( (end_date - start_date) * 100) + '%';
Log.d("type", "Date parsed : " + p);
}
答案1
得分: 2
你在不考虑时区的情况下无法正确执行这个操作。
private void getpercentage(String dateTimeStart, String dateTimeExpiration) {
ZoneId zone = ZoneId.systemDefault();
ZonedDateTime start = LocalDateTime.parse(dateTimeStart.replace(" ", "T"))
.atZone(zone);
ZonedDateTime end = LocalDateTime.parse(dateTimeExpiration.replace(" ", "T"))
.atZone(zone);
long total = ChronoUnit.MICROS.between(start, end);
long passed = ChronoUnit.MICROS.between(start, ZonedDateTime.now(zone));
long percentage = passed * 100 / total;
System.out.println(String.valueOf(percentage) + " %");
}
要查看一天中已经过去了多少：
getpercentage("2020-05-30 00:00:00", "2020-05-31 00:00:00");
当在我的时区 Europe/Copenhagen 运行时：
91 %
为了说明时区的影响，当在印度/马尔代夫时区运行时：
103 %
因此，在那个时区中，5月30日已经结束，我们已经进入5月31日的 3%。
使用 long 类型和 ChronoUnit.MICROS（微秒）可以适用于长达 290,000 年的时间跨度。对于更长的时间跨度，选择更粗的时间单位。对于更准确和更短的时间跨度，使用更细的时间单位，即纳秒。
Java 9 及更高版本
long percentage = Duration.between(start, ZonedDateTime.now(zone))
.multipliedBy(100)
.dividedBy(Duration.between(start, end));
在 Java 9 中引入了重载的 Duration.dividedBy(Duration) 方法。这使我们可以使用 Duration 类进行计算，因此我们不需要决定使用特定的时间单位。
英文:
You can’t do that correctly without taking time zone into account.
private void getpercentage(String dateTimeStart, String dateTimeExpiration) {
ZoneId zone = ZoneId.systemDefault();
ZonedDateTime start = LocalDateTime.parse(dateTimeStart.replace( " " , "T" ) )
.atZone(zone);
ZonedDateTime end = LocalDateTime.parse(dateTimeExpiration.replace( " " , "T" ) )
.atZone(zone);
long total = ChronoUnit.MICROS.between(start, end);
long passed = ChronoUnit.MICROS.between(start, ZonedDateTime.now(zone));
long percentage = passed * 100 / total;
System.out.println(String.valueOf(percentage) + " %");
}
To see how much of the day has passed:
getpercentage("2020-05-30 00:00:00", "2020-05-31 00:00:00");
When run right now in my time zone, Europe/Copenhagen:
> 91 %
To illustrate my point about time zone: when instead run in Indian/Maldives time zone:
> 103 %
So in that time zone 30th May is already over and we’re 3 % into 31st May.
Using the long type and ChronoUnit.MICROS (microseconds) will work for spans of time up to 290 000 years. For a longer span, choose a coarrser unit. For more accuracy and a shorter span, use a finer unit, that is, nanoseconds.
Java 9 and later
long percentage = Duration.between(start, ZonedDateTime.now(zone))
.multipliedBy(100)
.dividedBy(Duration.between(start, end));
The overloaded Duration.dividedBy(Duration) method was introduced in Java 9. This allows us to use the Duration class for the calculation so we don’t need to decide on a specific time unit.
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