Joda time : How to convert String to LocalDate?

Question

How to specify the format string to convert the date alone from string. In my case, only the date part is relevant

Constructing it as DateTime fails:

String dateString = "2009-04-17";
DateTimeFormatter formatter = DateTimeFormat.forPattern("yyyy-MM-dd");
DateTime dateTime = formatter.parseDateTime(dateString);

with error java.lang.IllegalArgumentException: Invalid format: "2011-04-17" is too short

Probably because I should use LocalDate instead. But, I do not see any formatter for LocalDate . What is the best way to convert String dateString = "2009-04-17"; into LocalDate (or something else if that is not the right representation)

thanks...

score 60 · Accepted Answer · edited Nov 21 '14 at 21:51

60

You're probably looking for LocalDate(Object). It's a bit confusing since it takes a generic Object, but the docs indicate that it will use a ConverterManager that knows how to handle a String if you pass a String to the constructor, e.g.

LocalDate myDate = new LocalDate("2010-04-28");

edited Nov 21 '14 at 21:51

Michael Myers

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answered Apr 27 '10 at 13:58

Hank Gay

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It certainly is a potentially confusing Javadoc entry. – SteveD Apr 27 '10 at 14:20
thanks a lot for the pointer... I'm bit confused how to use ConverterManager. How do I pass the string to it? Do I need need to add a partial converter to it? but it says by default it accepts string for partial convert. If you could give an example, it would be great help.. thanks – bsr Apr 27 '10 at 15:27
1

Sorry my answer wasn't clear enough, but it looks like you figured it out. I did indeed mean `final LocalDate myDate = new LocalDate("2010-04-28");` – Hank Gay Apr 28 '10 at 19:24
3

So does this *always* want the format of the string in 'YYYY-MM-DD' ? or could other platforms require different orders ? (I'm trying to just validate a date string : and for my purposes I always want it in YYYY-MM-DD) – monojohnny Jan 26 '16 at 16:58

score 20 · Answer 2 · answered Aug 22 '13 at 11:05

20

Use the parse(String) method.

LocalDate date = LocalDate.parse("2009-04-17");

answered Aug 22 '13 at 11:05

JodaStephen

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score 10 · Answer 3 · answered Feb 12 '16 at 00:41

There's a somewhat subtle bug-ish issue with using LocalDate.parse() or new LocalDate(). A code snippet is worth a thousand words. In the following example in the scala repl I wanted to get a Local date in a string format yyyyMMdd. LocalDate.parse() is happy to give me an instance of a LocalDate, but it's not the correct one (new LocalDate() has the same behavior):

scala> org.joda.time.LocalDate.parse("20120202")
res3: org.joda.time.LocalDate = 20120202-01-01

I give it Feb 2, 2016 in the format yyyyMMdd and I get back a date of January 1, 20120202. I'm going out on a limb here: I don't think that this is what it should be doing. Joda uses 'yyyy-MM-dd' as the default but implicitly will accept a string with no '-' characters, thinking you want January 1 of that year? That does not seem like a reasonable default behavior to me.

Given this, it seems to me that using a joda date formatter that can't be so easily fooled is a better solution to parsing a string. Moreover, LocalDate.parse() should probably throw an exception if the date format is not 'yyyy-MM-dd':

scala> val format = org.joda.time.format.DateTimeFormat.forPattern("yyyyMMdd")
format: org.joda.time.format.DateTimeFormatter = org.joda.time.format.DateTimeFormatter@56826a75

scala> org.joda.time.LocalDate.parse("20120202", format)
res4: org.joda.time.LocalDate = 2012-02-02

this will cause other formats to fail so you don't get this odd buggy behavior:

scala> val format = org.joda.time.format.DateTimeFormat.forPattern("yyyy-MM-dd")
format: org.joda.time.format.DateTimeFormatter = org.joda.time.format.DateTimeFormatter@781aff8b

scala> org.joda.time.LocalDate.parse("20120202", format)
java.lang.IllegalArgumentException: Invalid format: "20120202" is too short
  at org.joda.time.format.DateTimeFormatter.parseLocalDateTime(DateTimeFormatter.java:900)
  at org.joda.time.format.DateTimeFormatter.parseLocalDate(DateTimeFormatter.java:844)
  at org.joda.time.LocalDate.parse(LocalDate.java:179)
  ... 65 elided

which is a much more sane behavior than returning a date in the year 20120202.

Joda clearly statis in the javadocs: `It accepts formats described by the following syntax: date-element = std-date-element | ord-date-element | week-date-element std-date-element = yyyy ['-' MM ['-' dd]] ord-date-element = yyyy ['-' DDD] week-date-element = xxxx '-W' ww ['-' e] `. I think this is quite sane behaviour. — Czar, Jun 15 '17 at 06:01
stating in the docs is one thing, giving a big pit 'o failure to fall into is another, methinks — Kevin Won, Jun 27 '17 at 23:46

score 5 · Answer 4 · answered Feb 12 '16 at 06:58

In my case, incoming string may be in one of two formats. So I first try to parse string with more specific format:

String s = "2016-02-12";
LocalDateTime ldt;
try {
    ldt = LocalDateTime.parse(s, DateTimeFormat.forPattern("YYYY-MM-dd HH:mm"));
}
catch (IllegalArgumentException e) {
    ldt = LocalDateTime.parse(s, DateTimeFormat.forPattern("YYYY-MM-dd"));
}

score 1 · Answer 5 · edited Dec 07 '15 at 12:42

1

You can use LocalDate.of with the year, month and day passed as separate arguments:

LocalDate date1 = LocalDate.of(2009, 4, 17);
LocalDate date2 = LocalDate.of(2009, Month.APRIL, 17);

edited Dec 07 '15 at 12:42

trincot

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answered Dec 07 '15 at 12:19

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score 0 · Answer 6 · edited Jul 13 '14 at 19:27

0

This worked for me:

LocalDate d1 = LocalDate.parse("2014-07-19");
LocalDate dNow = LocalDate.now();  // Current date

edited Jul 13 '14 at 19:27

hichris123

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answered Jul 13 '14 at 18:57

CharlesF

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What's the point of this answer? The accepted answer is better, with simpler code, and also gives an explanation. – Basil Bourque Jul 13 '14 at 19:34

Joda time : How to convert String to LocalDate?

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