Java/Groovy - simple date reformatting

Question

I'm new to Java/Groovy development and I have a simple string that I would like to reformat, however I get an 'Unparseable date' error when I attempt to run the following:

import java.text.SimpleDateFormat 
import java.util.Date

String oldDate
Date date
String newDate 

oldDate = '04-DEC-2012'
date = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss.S").parse(oldDate)
newDate = new SimpleDateFormat("M-d-yyyy").format(date) 

println newDate

I'm sure it's something simple, but the solution eludes me. Can anyone help?

Your date is given in "DD-MMM-YYYY" pattern, and you are trying to parse something else... — posdef, Jan 17 '13 at 16:21
duplicate http://stackoverflow.com/questions/11135675/unparseable-date-30-jun-12 — CAMOBAP, Jan 17 '13 at 16:22
Not knowing Grrovy for new readers to this question I strongly recommend you don’t use `SimpleDateFormat` and `Date`. Those classes are poorly designed and long outdated, the former in particular notoriously troublesome. Instead use `LocalDate`, `DateTimeFormatterBuilder` and `DateTimeFormatter`, all from [java.time, the modern Java date and time API](https://docs.oracle.com/javase/tutorial/datetime/). See [this answer by user7605325](https://stackoverflow.com/a/46645976/5772882). — Ole V.V., May 16 '22 at 17:13

score 93 · Accepted Answer · answered Jan 17 '13 at 16:20

93

With Groovy, you don't need the includes, and can just do:

String oldDate = '04-DEC-2012'
Date date = Date.parse( 'dd-MMM-yyyy', oldDate )
String newDate = date.format( 'M-d-yyyy' )

println newDate

To print:

12-4-2012

answered Jan 17 '13 at 16:20

tim_yates

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@Andreas 7 years later, the link is http://docs.groovy-lang.org/docs/groovy-2.4.4/html/groovy-jdk/java/util/Date.html#parse(java.lang.String,%20java.lang.String) – tim_yates Jun 26 '20 at 10:18

score 4 · Answer 2 · answered Jan 17 '13 at 16:20

4

Your DateFormat pattern does not match you input date String. You could use

new SimpleDateFormat("dd-MMM-yyyy")

answered Jan 17 '13 at 16:20

Reimeus

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score 1 · Answer 3 · answered Jan 17 '13 at 16:21

1

oldDate is not in the format of the SimpleDateFormat you are using to parse it.

Try this format: dd-MMM-yyyy - It matches what you're trying to parse.

answered Jan 17 '13 at 16:21

Jesan Fafon

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Ediney Andrade · Answer 4 · 2022-05-16T16:32:13.993

1

//Groovy Script

import java.util.Date   
import java.util.TimeZone   
tz = TimeZone.getTimeZone("America/Sao_Paulo")   
def date = new Date()   
def dt = date.format("yyyy-MM-dd HH:mm:ss", timezone=tz)   
println dt //formatado   
println date // formatado porém, horario do Sistema em GMT.

edited May 16 '22 at 16:32

answered May 16 '22 at 16:25

Ediney Andrade

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Thanks for wanting to contribute. I strongly recommend you don’t use `Date` and `TimeZone`. Those classes are poorly designed and long outdated. Instead use classes from [java.time, the modern Java date and time API](https://docs.oracle.com/javase/tutorial/datetime/). Also and quite importantly, in what way does your answer answer the question? I believe the question was about reformatting from a format like `04-DEC-2012` into `12-4-2012`. – Ole V.V. May 16 '22 at 17:15
@OleV.V. How would the OPs problem be solved with java.time? Do you have an example? – philler82 Aug 02 '22 at 08:23
In Java: Parse `oldDate` from the qusetion using [my answer here](https://stackoverflow.com/a/66680435/5772882), only the pattern needs to be `dd-MMM-uuuu` (four digit year). For formatting the `LocalDate` from that answer into `12-4-2012`, use `date.format(DateTimeFormatter.ofPattern("M-d-u"))`. – Ole V.V. Aug 03 '22 at 03:15
Olá @OleV.V., realmente descrevi minha resposta de maneira errada, agradeço as suas dicas. – Ediney Andrade Aug 11 '22 at 17:38

Java/Groovy - simple date reformatting

4 Answers4