Unable to obtain LocalDateTime from TemporalAccessor when parsing LocalDateTime (Java 8)

Question

I am simply trying to convert a date string into a DateTime object in Java 8. Upon running the following lines:

DateTimeFormatter formatter = DateTimeFormatter.ofPattern("yyyyMMdd");
LocalDateTime dt = LocalDateTime.parse("20140218", formatter);

I get the following error:

Exception in thread "main" java.time.format.DateTimeParseException: 
Text '20140218' could not be parsed: 
Unable to obtain LocalDateTime from TemporalAccessor: 
{},ISO resolved to 2014-02-18 of type java.time.format.Parsed
    at java.time.format.DateTimeFormatter.createError(DateTimeFormatter.java:1918)
    at java.time.format.DateTimeFormatter.parse(DateTimeFormatter.java:1853)
    at java.time.LocalDateTime.parse(LocalDateTime.java:492)

The syntax is identical to what has been suggested here, yet I am served with an exception. I am using JDK-8u25.

Representational

why are you using LocalDateTime without a time? – Cusped

Answer 1

It turns out Java does not accept a bare Date value as DateTime. Using LocalDate instead of LocalDateTime solves the issue:

DateTimeFormatter formatter = DateTimeFormatter.ofPattern("yyyyMMdd");
LocalDate dt = LocalDate.parse("20140218", formatter);

Representational

For what it's worth: I had this same problem even when using LocalDate and not LocalDateTime. The issue was that I had created my DateTimeFormatter using .withResolverStyle(ResolverStyle.STRICT);, so I had to use date pattern uuuuMMdd instead of yyyyMMdd (i.e. "year" instead of "year-of-era")! – Wintery

@ZeroOne's comment should be included as part of the selected answer. – Bon

@Bon I've posted my comment as a separate answer, you may upvote that one. Eventually it will surpass the accepted one in the number of votes... – Wintery

@iulian-david 's answer was more helpful here and actually solved the problem of parsing a datetime that may or may not have a time part. – Alcestis

"Java does not accept a bare Date value as DateTime"! What a rediculous feature! – Sideswipe

For those who don't want to convert to localeDate see Julian David answer – Streeter

Answer 2

If you really need to transform a date to a LocalDateTime object, you could use the LocalDate.atStartOfDay(). This will give you a LocalDateTime object at the specified date, having the hour, minute and second fields set to 0:

final DateTimeFormatter formatter = DateTimeFormatter.ofPattern("yyyyMMdd");
LocalDateTime time = LocalDate.parse("20140218", formatter).atStartOfDay();

Socialite

Correction: set to whatever time it would be at the start of that day. – Mats

LocalDateTime.from seems unnecessary, as atStartOfDay() already returns LocalDateTime. – Lumbar

scala: val time = LocalDate.parse("20171220", DateTimeFormatter.ofPattern("yyyyMMdd")).atStartOfDay.format(DateTimeFormatter.ofPattern("yyyy-MM-dd HH:mm:ss")) – Bailsman

Answer 3

For what is worth if anyone should read again this topic(like me) the correct answer would be in DateTimeFormatter definition, e.g.:

private static DateTimeFormatter DATE_FORMAT =  
            new DateTimeFormatterBuilder().appendPattern("dd/MM/yyyy[ [HH][:mm][:ss][.SSS]]")
            .parseDefaulting(ChronoField.HOUR_OF_DAY, 0)
            .parseDefaulting(ChronoField.MINUTE_OF_HOUR, 0)
            .parseDefaulting(ChronoField.SECOND_OF_MINUTE, 0)
            .toFormatter(); 

One should set the optional fields if they will appear. And the rest of code should be exactly the same.

Edit : usefull thing from wittyameta comment :

Remember to add the parseDefaulting AFTER you have called appendPattern. Otherwise it'll give DateTimeParseException

Phiphenomenon

This is true universal solution for instance for such method: Long getFileTimestamp(String file, Pattern pattern, DateTimeFormatter dtf, int group); Here you have different patterns and DateTimeFormetter, w/ and w/o time specified. – Translate

Can it be a static field? I have not found in the Javadoc that an instance created that way is thread-safe – Burgwell

Remember to add the parseDefaulting AFTER you have called appendPattern. Otherwise it'll give DateTimeParseException. – Gambit

when using HH for hours in the pattern, i get 00 for AM hours – Ashmead

If you want to parse fraction of second by JAVA 8, try to visit this log. #22588551 – Lecroy

Answer 4

For anyone who landed here with this error, like I did:

Unable to obtain LocalDateTime from TemporalAccessor: {HourOfAmPm=0, MinuteOfHour=0}

It came from a the following line:

LocalDateTime.parse(date, DateTimeFormatter.ofPattern("M/d/yy h:mm"));

It turned out that it was because I was using a 12hr Hour pattern on a 0 hour, instead of a 24hr pattern.

Changing the hour to 24hr pattern by using a capital H fixes it:

LocalDateTime.parse(date, DateTimeFormatter.ofPattern("M/d/yy H:mm"));

Grueling

Answer 5

This is a really unclear and unhelpful error message. After much trial and error I found that LocalDateTime will give the above error if you do not attempt to parse a time. By using LocalDate instead, it works without erroring.

This is poorly documented and the related exception is very unhelpful.

Amianthus

Answer 6

Expanding on retrography's answer..: I had this same problem even when using LocalDate and not LocalDateTime. The issue was that I had created my DateTimeFormatter using .withResolverStyle(ResolverStyle.STRICT);, so I had to use date pattern uuuuMMdd instead of yyyyMMdd (i.e. "year" instead of "year-of-era")!

DateTimeFormatter formatter = new DateTimeFormatterBuilder()
  .parseStrict()
  .appendPattern("uuuuMMdd")
  .toFormatter()
  .withResolverStyle(ResolverStyle.STRICT);
LocalDate dt = LocalDate.parse("20140218", formatter);

(This solution was originally a comment to retrography's answer, but I was encouraged to post it as a stand-alone answer because it apparently works really well for many people.)

Wintery

The answer to why "u" instead of "y"has been answered in this link uuuu-versus-yyyy-in-datetimeformatter-formatting-pattern-codes-in-java @Peru – Evzone

Answer 7

If the date String does not include any value for hours, minutes and etc you cannot directly convert this to a LocalDateTime. You can only convert it to a LocalDate, because the string only represent the year,month and date components it would be the correct thing to do.

DateTimeFormatter dtf = DateTimeFormatter.ofPattern("yyyyMMdd");
LocalDate ld = LocalDate.parse("20180306", dtf); // 2018-03-06

Anyway you can convert this to LocalDateTime.

DateTimeFormatter dtf = DateTimeFormatter.ofPattern("yyyyMMdd");
LocalDate ld = LocalDate.parse("20180306", dtf);
LocalDateTime ldt = LocalDateTime.of(ld, LocalTime.of(0,0)); // 2018-03-06T00:00

Excommunicative

Also make sure the format is correct. This fix didn't work for me until because I set the format to yyyy-mm-dd when it should have been yyyy-MM-dd. – Thalassa

I want to upvote this 10 times if I can – Crave

Answer 8

 DateTimeFormatter format = new DateTimeFormatterBuilder()
                            .appendPattern("yyyy-MM-dd")
                            .parseDefaulting(ChronoField.HOUR_OF_DAY, 0)
                            .parseDefaulting(ChronoField.MINUTE_OF_HOUR, 0)
                            .parseDefaulting(ChronoField.SECOND_OF_MINUTE, 0)
                            .parseDefaulting(ChronoField.MILLI_OF_SECOND, 0)
                            .toFormatter();

Works for me

Benco

for minimum, only ChronoField.HOUR_OF_DAY is needed, it does the same thing with the other 3 removed (MINUTE_OF_HOUR, SECOND_OF_MINUTE, MILLI_OF_SECOND) – Dorotea

Answer 9

You do not need to define a DateTimeFormatter

You do not need to define a DateTimeFormatter to parse the given date string. You can use the OOTB (Out-Of-The-Box), DateTimeFormatter.BASIC_ISO_DATE to parse it.

Demo:

import java.time.LocalDate;
import java.time.LocalDateTime;
import java.time.LocalTime;
import java.time.format.DateTimeFormatter;

public class Main {
    public static void main(String[] args) {
        LocalDate date = LocalDate.parse("20140218", DateTimeFormatter.BASIC_ISO_DATE);
        System.out.println(date);

        // In case you need an instance of LocalDateTime
        LocalDateTime ldt = date.atTime(LocalTime.MIN);
        System.out.println(ldt);
    }
}

Output:

2014-02-18
2014-02-18T00:00

ONLINE DEMO

Learn more about the modern Date-Time API^* from Trail: Date Time.

---

^{* If you are working for an Android project and your Android API level is still not compliant with Java-8, check Java 8+ APIs available through desugaring. Note that Android 8.0 Oreo already provides support for java.time. Check this answer and this answer to learn how to use java.time API with JDBC.}

Whitethorn

Answer 10

In cases where you simply want to take a format (whether or not it has time) and want to parse to a LocalDateTime, you can do the following.

LocalDateTime parseDateTime(String dateTime, DateTimeFormatter fmt) {
  return fmt.parse(dateTime, t -> {
    LocalDate date = t.query(TemporalQueries.localDate());
    LocalTime time = t.query(TemporalQueries.localTime());
    return LocalDateTime.of(date, time != null ? time : LocalTime.MIDNIGHT);
  });
}

I needed this because I was getting the date/time pattern as a parameter for a custom Spark UDF.

Periosteum

Answer 11

This works fine

public class DateDemo {
    public static void main(String[] args) {
        DateTimeFormatter formatter = DateTimeFormatter.ofPattern("dd-MM-yyyy hh:mm");
        String date = "16-08-2018 12:10";
        LocalDate localDate = LocalDate.parse(date, formatter);
        System.out.println("VALUE="+localDate);

        DateTimeFormatter formatter1 = DateTimeFormatter.ofPattern("dd-MM-yyyy HH:mm");
        LocalDateTime parse = LocalDateTime.parse(date, formatter1);
        System.out.println("VALUE1="+parse);
    }
}

output:

VALUE=2018-08-16
VALUE1=2018-08-16T12:10

Presentative

Answer 12

Try this one:

DateTimeFormatter dateTimeFormatter = DateTimeFormatter.ofPattern("MM-dd-yyyy"); 
LocalDate fromLocalDate = LocalDate.parse(fromdstrong textate, dateTimeFormatter);

You can add any format you want. That works for me!

Doti

Answer 13

I arrived at this problem because my input string didn't have a year in it:

input string: Tuesday, June 8 at 10:00 PM
formatter: DateTimeFormatter.ofPattern("EEEE, MMMM d 'at' h:mm a", Locale.US);

I knew the year so I just appended it to get:

input string: Tuesday, June 8 at 6:30 PM 2021
formatter: DateTimeFormatter.ofPattern("EEEE, MMMM d 'at' h:mm a uuuu", Locale.US);

Venusberg