String datetime convert to LocalDateTime object

Question

I want to convert to this string to LocalDateTime object. How can I do that?

"Thu Aug 29 17:46:11 GMT+05:30 2019"

I already try something, but it didn't work.

    final String time = "Thu Aug 29 17:46:11 GMT+05:30 2019";
    final String format = "ddd MMM DD HH:mm:ss 'GMT'Z YYYY";

    DateTimeFormatter dateTimeFormatter = DateTimeFormat.forPattern(format);
    LocalDateTime localDateTime = LocalDateTime.parse(time, dateTimeFormatter);

Exception in thread "main" java.lang.IllegalArgumentException: Invalid format: "Thu Aug 29 17:46:11" at org.joda.time.format.DateTimeFormatter.parseLocalDateTime(DateTimeFormatter.java:900) at org.joda.time.LocalDateTime.parse(LocalDateTime.java:168)

Answer 1

tl;dr

FYI, the Joda-Time project is now in maintenance mode, advising migration to the java.time classes. See Tutorial by Oracle.

OffsetDateTime.parse( 
    "Thu Aug 29 17:46:11 GMT+05:30 2019" , 
    DateTimeFormatter.ofPattern( "EEE MMM d HH:mm:ss OOOO uuuu").withLocale( Locale.US ) 
)
.toString()

2019-08-29T17:46:11+05:30

LocalDateTime cannot represent a moment

"Thu Aug 29 17:46:11 GMT+05:30 2019"

I want to convert to this string to LocalDateTime object.

You cannot.

• The input represents a moment, a specific point on the timeline.
• A LocalDateTime cannot represent a moment. A LocalDateTime has only a date and a time-of-day but lacks the context of a time zone or offset-from-UTC.

Trying to handle your input as a LocalDateTime would mean discarding valuable information. That would be like handling a amount of money as simply a BigDecimal while throwing away information about which currency.

OffsetDateTime

You input string includes an offset-from-UTC of five and a half hours ahead. So parse as an OffsetDateTime object.

Define a custom formatting pattern to match your input, using the DateTimeFormatter class.

Define

String input = "Thu Aug 29 17:46:11 GMT+05:30 2019" ;
DateTimeFormatter f = DateTimeFormatter.ofPattern( "EEE MMM d HH:mm:ss OOOO uuuu").withLocale( Locale.US );
OffsetDateTime odt = OffsetDateTime.parse( input , f ) ;

odt.toString(): 2019-08-29T17:46:11+05:30

Tip: That input format is terrible. Educate the publisher of those input string about the standard ISO 8601 for practical date-time formats.

---

About java.time

The java.time framework is built into Java 8 and later. These classes supplant the troublesome old legacy date-time classes such as java.util.Date, Calendar, & SimpleDateFormat.

To learn more, see the Oracle Tutorial. And search Stack Overflow for many examples and explanations. Specification is JSR 310.

The Joda-Time project, now in maintenance mode, advises migration to the java.time classes.

You may exchange java.time objects directly with your database. Use a JDBC driver compliant with JDBC 4.2 or later. No need for strings, no need for java.sql.* classes.

Where to obtain the java.time classes?

• Java SE 8, Java SE 9, Java SE 10, Java SE 11, and later - Part of the standard Java API with a bundled implementation.
  • Java 9 adds some minor features and fixes.
• Java SE 6 and Java SE 7
  • Most of the java.time functionality is back-ported to Java 6 & 7 in ThreeTen-Backport.
• Android
  • Later versions of Android bundle implementations of the java.time classes.
  • For earlier Android (<26), the ThreeTenABP project adapts ThreeTen-Backport (mentioned above). See How to use ThreeTenABP….

Answer 2

Note that Joda-Time is considered to be a largely “finished” project. No major enhancements are planned. If using Java SE 8, please migrate to java.time (JSR-310).

This is quoted from the Joda-Time home page. I should say that it endorses the answer by Basil Bourque. In any case if you insist on sticking to Joda-Time for now, the answer is:

    final String time = "Thu Aug 29 17:46:11 GMT+05:30 2019";
    final String format = "EEE MMM dd HH:mm:ss 'GMT'ZZ YYYY";

    DateTimeFormatter dateTimeFormatter = DateTimeFormat.forPattern(format)
            .withLocale(Locale.ENGLISH)
            .withOffsetParsed();
    DateTime dateTime = DateTime.parse(time, dateTimeFormatter);
    System.out.println(dateTime);

Output:

2019-08-29T17:46:11.000+05:30

• In the format pattern string
  • You need EEE for day of week. d is for day of month.
  • You need lowercase dd for day of month; uppercase DD is for day of year
  • I have put in ZZ because according to the docs this is for offset with a colon; Z works in practice too
• Since Thu and Aug are in English, you need an English speaking locale. Since I believe your string comes from Date.toString() originally, which always produces English, I found Locale.ROOT appropriate.
• I found it better to parse into a DateTIme. To preserve the offset from the string we need to specify that through withOffsetParsed() (you can always convert to LocalDateTime later if desired).

Links

• Joda-Time home page
• Related question: Joda Time parse a date with timezone and retain that timezone
• Documentation of org.joda.time.format.DateTimeFormat with the format pattern letters including their case