如何使用毫秒获得android中两个日期之间的差异？

Question

My SimpleDateFormat format is "HH:mm:ss.SSS"

My example time: "00:01:20.442"

How to get (extract) milliseconds 442 to string?

I found code:

long diff = date1.getTime() - date2.getTime();
long mseconds = ?????????;
long seconds = diff / 1000;
long minutes = seconds / 60;
long hours = minutes / 60;
long days = hours / 24;

System.out.println("Milliseconds : "+ String.valueOf(mseconds));

PS I'm use API 19 (Adroid 4.4.2)

Answer 1

You take the remainder of dividing by 1000, using the remainder operator :

long mseconds = diff % 1000;

But note that the milliseconds value you've asked for (442) doesn't match what you're doing to get seconds , minutes , etc. In seconds , you'll get the total number of seconds between the dates, which could be in the hundreds of thousands depending on the dates, not just 0-59.

If the goal is to get days, hours (within the day), minutes (within the hour), etc., then:

long mseconds = diff % 1000;
long seconds = (diff / 1000) % 60;
long minutes = (seconds / 60) % 60;
long hours = (minutes / 60) % 24;
long days = hours / 24;

Answer 2

Using the Joda Time library (which in my opinion should be in every project that uses time):

final long millis = DateTime.parse("00:01:20.442", DateTimeFormat.forPattern("HH:mm:ss.SSS")).getMillisOfSecond();
assertEquals(442, millis);

Or, if you want all of them:

final DateTime dt = DateTime.parse("00:01:20.442", DateTimeFormat.forPattern("HH:mm:ss.SSS"));

final long millis = dt.getMillisOfSecond(); //442
final long second = dt.getSecondOfMinute(); //20
final long min = dt.getMinuteOfHour(); //1
final long hour = dt.getHourOfDay(); //0

Answer 3

Why don't you simply split the String by . and use the second element? Like:

long millis = Long.parseLong(dateStr.split(".")[1]);

Where dateStr is a String of form HH:mm:ss.SSS .

It is much better solution than using a 3rd party library for simple task.