java.time.DateTimeException: Unable to extract ZoneId from temporal

Question

When I run the first segment, it is perfectly fine and generate an output. but in second case when I run this segment 2, It generates

DateTimeException : Unable to extract ZoneId from temporal.

segment 1:

LocalDate ld = LocalDate.now();
System.out.println(DateTimeFormatter.ofLocalizedDate(FormatStyle.FULL).format(ld));

segment 2:

LocalDateTime ldt = LocalDateTime.now();
DateTimeFormatter dtf = DateTimeFormatter.ofLocalizedDateTime(FormatStyle.FULL);
System.out.println(dtf.format(ldt));

refer to https://stackoverflow.com/questions/49458878/java-adding-timezone-to-datetimeformatter — RamPrakash, Dec 30 '19 at 13:08

Youcef LAIDANI · Answer 1 · 2021-03-19T09:33:19.227

I think It is a little complicated to explain, because you are mixing between two things ofLocalizedDate, ofLocalizedDateTime and the FormatStyle :

In the first case you are calling ofLocalizedDate with the FormatStyle.FULL so you are ignoring the time part.

In the second case you are calling ofLocalizedDateTime also with FormatStyle.FULL which will include all the parts of the date, which is not the case for LocalDate or LocalDateTime.

To be sure lets try with MEDIUM, or SHORT instead of FULL :

DateTimeFormatter.ofLocalizedDateTime(FormatStyle.MEDIUM).format(ldt)
=> 30 déc. 2019 à 14:57:40 - without any exception

For more details check the comments here :

/**
 * Full text style, with the most detail.
 * For example, the format might be 'Tuesday, April 12, 1952 AD' or '3:30:42pm PST'.
 */
FULL,
/**
 * Long text style, with lots of detail.
 * For example, the format might be 'January 12, 1952'.
 */
LONG,
/**
 * Medium text style, with some detail.
 * For example, the format might be 'Jan 12, 1952'.
 */
MEDIUM,
/**
 * Short text style, typically numeric.
 * For example, the format might be '12.13.52' or '3:30pm'.
 */
SHORT;

To resume we can create a this table :

	ofLocalizedTime	ofLocalizedDate	ofLocalizedDateTime
LocalTime	MEDIUM, SHORT
LocalDate		FULL, LONG, MEDIUM, SHORT
LocalDateTime	MEDIUM, SHORT	FULL, LONG, MEDIUM, SHORT	MEDIUM, SHORT
ZonedDateTime	FULL, LONG, MEDIUM, SHORT	FULL, LONG, MEDIUM, SHORT	FULL, LONG, MEDIUM, SHORT
OffsetDateTime	MEDIUM, SHORT	FULL, LONG, MEDIUM, SHORT	MEDIUM, SHORT

=> FULL, LONG, MEDIUM, SHORT are FormatStyle

You can read it as LocalDateTime can use ofLocalizedDate with all the format styles, and no can't accept any FormatStyle with ofLocalizedDateTime

Please explain more detail Why using extra think ZonedDateTime — Ng Sharma, Dec 30 '19 at 12:49
@NgSharma ok check my answer now, I think i make it more easy yo be clear — Youcef LAIDANI, Dec 30 '19 at 13:29

score 3 · Answer 2 · answered Dec 30 '19 at 13:10

You are confusing "localized" and "local":

ofLocalizedDateTime: Returns a locale specific date-time formatter
LocalDateTime: A date-time without a time-zone

As you can see, they are two entirely different terms.

Now, try supplying a ZonedDateTime value, so you can see why it wants a ZoneId.

ZonedDateTime zdt = ZonedDateTime.now();
DateTimeFormatter dtf = DateTimeFormatter.ofLocalizedDateTime(FormatStyle.FULL);
System.out.println(dtf.format(zdt));

Output (locale: en_US, time zone: America/New_York)

Monday, December 30, 2019 at 8:09:16 AM Eastern Standard Time

As you can see, it needs the time zone to know that the time is "Eastern Standard Time".

If you reduce the time style from FULL to MEDIUM, the time zone is no longer needed.

LocalDateTime ldt = LocalDateTime.now();
DateTimeFormatter dtf = DateTimeFormatter.ofLocalizedDateTime(FormatStyle.FULL, FormatStyle.MEDIUM);
System.out.println(dtf.format(ldt));

Output

Monday, December 30, 2019, 8:09:16 AM

java.time.DateTimeException: Unable to extract ZoneId from temporal

2 Answers2