CODEWITHSUNDEEP
javajodatimeandroid-jodatime
Nimantha
Nimantha

Reputation: 195

String datetime convert to LocalDateTime object

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)

Upvotes: 2

Views: 672

Answers (3)

Anonymous
Anonymous

Reputation: 86232

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

Upvotes: 3

Krishna Vyas
Krishna Vyas

Reputation: 1028

The format string you provided for parsing doesn't looks right with the text format you've actually got. You need to parse first, then format. Just test below code,

    SimpleDateFormat format = new SimpleDateFormat("EEE MMM dd HH:mm:ss z yyyy",Locale.getDefault());
    Date dt = null;
    try {
        dt = format.parse("Thu Aug 29 17:46:11 GMT+05:30 2019");
        SimpleDateFormat out = new SimpleDateFormat("MMM dd, yyyy h:mm a");
        String output = out.format(dt);
        Log.e("OUTPUT",output);
    } catch (Exception e) {
        e.printStackTrace();
    }

Upvotes: 1

Basil Bourque
Basil Bourque

Reputation: 338326

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?

Upvotes: 4

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