Menu
By default, the toString method of Instant uses the DateTimeFormatter.ISO_INSTANT formatter. That formatter won’t print the digits for fraction-of-second if they happen to be 0.
java-time examples:
2015-10-08T17:13:07.589Z
2015-10-08T17:13:07Z
Joda-Time examples (and what I'd expect from java.time):
2015-10-08T17:13:07.589Z
2015-10-08T17:13:07.000Z
This is really frustrating to parse in some systems. Elasticsearch was the first problem I encountered, there's no pre-defined format that supports optional millis, but I can probably work around that with a custom format. The default just seems wrong.
It appears that you can’t really build your own format string for Instants anyway. Is the only option implementing my own java.time.format.DateTimeFormatterBuilder.InstantPrinterParser?
267
The Date/Time API in Java works with the ISO 8601 format by default, which is (yyyy-MM-dd) . All Dates by default follow this format, and all Strings that are converted must follow it if you're using the default formatter.
For time patterns, use mm for two-digit minute and ss for two-digit second. The hh pattern generates the two-digit hour for a 12-hour clock (e.g., 6PM is "06") and HH generates the two-digit hour for a 24-hour clock (e.g., 6PM is "18").
Java 8 provides APIs for the easy formatting of Date and Time: LocalDateTime localDateTime = LocalDateTime. of(2015, Month. JANUARY, 25, 6, 30);
Yes, it is: DateTimeFormat is thread-safe and immutable, and the formatters it returns are as well.
To learn how to format date and time objects in Java 8, follow these four steps. Open your text editor and create the Java program that will demonstrate formatting date and time. Type in the following Java statements: The DateTimeFormatter class can be used to format date/time objects.
The Java Date Time API was added from Java version 8. The millis () method of Clock class returns the current instant of the clock in milliseconds. A millisecond instant is measured from 1970-01-01T00:00Z (UTC) to the current time.
How to format Java LocalDateTime as ISO_DATE_TIME format. Java 8 Object Oriented Programming Programming. At first, set the date: LocalDateTime dateTime = LocalDateTime.of (2019, Month.JULY, 9, 10, 20); Now, format the datetime as ISO_DATE_TIME format: String str = dateTime.format (DateTimeFormatter.ISO_DATE_TIME);
The java.text.DateFormat class provides various methods to format and parse date and time in java in language independent manner. The DateFormat class is an abstract class. java.text.Format is the parent class and java.text.SimpleDateFormat is the subclass of java.text.DateFormat class.
Just create a DateTimeFormatter that keeps three fractional digits.
DateTimeFormatter formatter = new DateTimeFormatterBuilder().appendInstant(3).toFormatter();
Then use it. For example:
System.out.println(formatter.format(Instant.now()));
System.out.println(formatter.format(Instant.now().truncatedTo(ChronoUnit.SECONDS)));
…prints (at the time I run it):
2015-10-08T21:26:16.571Z
2015-10-08T21:26:16.000Z
Excerpt of the class doc:
… The fractionalDigits parameter allows the output of the fractional second to be controlled. Specifying zero will cause no fractional digits to be output. From 1 to 9 will output an increasing number of digits, using zero right-padding if necessary. The special value -1 is used to output as many digits as necessary to avoid any trailing zeroes. …
141
If you love us? You can donate to us via Paypal or buy me a coffee so we can maintain and grow! Thank you!
Donate Us With
