Convert ms into a string date with Java 8

问题

I have a timestamp as ms and format this with a SimpleDateFormater like this:

SimpleDateFormat sdfDate = new SimpleDateFormat("MM/d/yyyy h:mm a");

return sdfDate.format(new Date(timeStamp));

Now I'd like to change this to use the new Java 8 abilities. Seems like I really can't find a way to get this working with the new Java 8 Classes. Anyone got a hint?

回答1:

If all you have is a millisecond value (assuming from the Unix Epoch) you can get an LocalDateTime using something like:

LocalDateTime ldt = LocalDateTime.ofInstant(Instant.ofEpochMilli(timeInMillis), ZoneId.systemDefault());
System.out.println(ldt);

Which can print something like:

2015-09-29T16:57:40.077

You can then format it using something like this:

System.out.println(ldt.format(DateTimeFormatter.ofPattern("MM/dd/yyyy h:mm a")));

Which can print something like (based on the original time from the previous example):

09/29/2015 4:57 PM

回答2:

I hope you can try this in Java 8 to get Date from timestamp:

timeStamp.toLocalDateTime().toLocalDate();

For formatting you can use LocalDateTime as:

String str = "1997-03-18 11:30";
DateTimeFormatter formatter = DateTimeFormatter.ofPattern("yyyy-MM-dd HH:mm");
LocalDateTime dateTime = LocalDateTime.parse(str, formatter);

来源：https://stackoverflow.com/questions/32837406/convert-ms-into-a-string-date-with-java-8