How to convert ISO 8601 Datetime into a specific datetime format in Java using Joda package

Question

I am using org.joda.time.DateTime; package to convert ISO 8601 datetime for Eg "2017-02-07T00:00:00.000+05:30" to a format "yyyy-MM-dd HH:mm:ss.SSS".

Code is :

String dateTimePattern = "yyyy-MM-dd HH:mm:ss.SSS";
DateTimeFormatter dtf = DateTimeFormat.forPattern(inputDateTimePattern);
DateTime jodatime = dtf.parseDateTime("2017-02-07T00:00:00.000+05:30");;
System.out.println("Converted datetime is: ",jodatime.toString(dtf))

But i get error mentioning

java.lang.IllegalArgumentException: Invalid format: is malformed at ".T00:00:00.000+05:30"

How to convert ISO 8601 datetime format in required format in java ?

Answer 1

tl;dr

Joda-Time is replaced by the java.time classes.

OffsetDateTime.parse( "2017-02-07T00:00:00.000+05:30" )

java.time

The Joda-Time project is now in maintenance mode, with its team advising migration to the java.time classes.

In java.time, your input string can be parsed directly as a OffsetDateTime object. No need to specify a formatting pattern.

OffsetDateTime odt = OffsetDateTime.parse( "2017-02-07T00:00:00.000+05:30" );

A time zone is a history of offsets for a particular region. So always better to use if you are certain of the intended time zone.

ZoneId z = ZoneId.of( "Asia/Kolkata" );  // Or "America/Montreal", etc.
ZonedDateTime zdt = odt.atZoneSameInstant();

Joda-Time

In Joda-Time, you can parse a string in standard ISO 8601 format with an offset-from-UTC in either of two ways:

• Constructor
  new DateTime( "2017-02-07T00:00:00.000+05:30" ) ;
• Static parse method
  DateTime.parse( "2017-02-07T00:00:00.000+05:30" )

These two routes are not the same! See the class doc from the parse method:

However, when this method is passed a date-time string with an offset, the offset is directly parsed and stored. As such, DateTime.parse("2010-06-30T01:20+02:00") and new DateTime("2010-06-30T01:20+02:00")) are NOT equal. The object produced via this method has a zone of DateTimeZone.forOffsetHours(2). The object produced via the constructor has a zone of DateTimeZone.getDefault().

Answer 2

Well... the solution might be a mix between 2 already existing answers here at Stack Overflow

First - look at this post How to parse and generate DateTime objects in ISO 8601 format which describes how to write such a code using C# (C# and JAVA are very similar)

Second - please use the SimpleDateFormat as described here How to parse a date?

This combination should do the trick

Answer 3

Looks like you got confused while using DateTimeFormat. Given time string is not in yyyy-MM-dd HH:mm:ss.SSS format. So you are getting the exception which is expected.

        SimpleDateFormat target = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss.SSS");
        SimpleDateFormat source = new SimpleDateFormat("yyyy-MM-dd'T'HH:mm:ssXXX");
        Date date=source.parse("2017-02-07T00:00:00+05:30");
        System.out.println(target.format(date));  // prints 2017-02-07 00:00:00.000

This code will format the date into yyyy-MM-dd HH:mm:ss.SSS.

Answer 4

Use the below method

public static Calendar toCalendar(String iso8601string) {
    DateTime dt = new DateTime(iso8601string);
    Date date = new Date(dt.getMillis());
    Calendar calendar = Calendar.getInstance();
    calendar.setTime(date);
    return calendar;
}