How to format a date in java?

Question

How can change this date format \"2011-09-07T00:00:00+02:00\" into the \"dd.MM.\" i.e \"07.09.\"

Thanks in advance!

Answer 1

Your code needs a little correction on the following line

Date date = inputDf.parse(input.substring(0,9));

In place of (0,9) you need to enter (0,10) and you will be getting the desired output.

Answer 2

Basically -

1. Create a date format object from the above string

2. Parse into a date object, and reformat however you prefer.

For example (I haven't tested this):

/*
 * REFERENCE:
 * http://javatechniques.com/blog/dateformat-and-simpledateformat-examples/
 */
import java.text.DateFormat;
import java.util.Date;

public class DateFormatExample1 {

    public static void main(String[] args) {
        // Make a new Date object. It will be initialized to the current time.
        DateFormat dfm = new SimpleDateFormat("yyyy-mm-dd HH:mm:ss");
        Date d = dfm.parse("2011-09-07 00:00:00");

        // See what toString() returns
        System.out.println(" 1. " + d.toString());

        // Next, try the default DateFormat
        System.out.println(" 2. " + DateFormat.getInstance().format(d));

        // And the default time and date-time DateFormats
        System.out.println(" 3. " + DateFormat.getTimeInstance().format(d));
        System.out.println(" 4. " +
            DateFormat.getDateTimeInstance().format(d));

        // Next, try the short, medium and long variants of the
        // default time format
        System.out.println(" 5. " +
            DateFormat.getTimeInstance(DateFormat.SHORT).format(d));
        System.out.println(" 6. " +
            DateFormat.getTimeInstance(DateFormat.MEDIUM).format(d));
        System.out.println(" 7. " +
            DateFormat.getTimeInstance(DateFormat.LONG).format(d));

        // For the default date-time format, the length of both the
        // date and time elements can be specified. Here are some examples:
        System.out.println(" 8. " + DateFormat.getDateTimeInstance(
            DateFormat.SHORT, DateFormat.SHORT).format(d));
        System.out.println(" 9. " + DateFormat.getDateTimeInstance(
            DateFormat.MEDIUM, DateFormat.SHORT).format(d));
        System.out.println("10. " + DateFormat.getDateTimeInstance(
            DateFormat.LONG, DateFormat.LONG).format(d));
    }
}

Answer 3

tl;dr

OffsetDateTime.parse( "2011-09-07T00:00:00+02:00" ).format( DateTimeFormatter.ofPattern( "dd.MM" )

java.time

The Question and other Answers use old legacy classes that have proven to be troublesome and confusing. They have been supplanted by the java.time classes.

Your input string is in standard ISO 8601 format. These formats are used by default in java.time classes. So no need to specify a formatting pattern.

OffsetDateTime odt = OffsetDateTime.parse( "2011-09-07T00:00:00+02:00" );

You can generate a String in your desired format.

DateTimeFormatter f = DateTimeFormatter.ofPattern( "dd.MM" );
String output = odt.format( f );

MonthDay

You want month and day-of-month. There is actually a class for that, MonthDay.

MonthDay md = MonthDay.from( odt );

You can generate a String in your desired format.

DateTimeFormatter f = DateTimeFormatter.ofPattern( "dd.MM" );
String output = md.format( f );

Answer 4

here is a sample

edited the code:

public static void main(String[] args) throws ParseException {
    String input = "2011-09-07T00:00:00+02:00";
    SimpleDateFormat inputDf = new SimpleDateFormat("yyyy-MM-dd");
    SimpleDateFormat outputDf = new SimpleDateFormat("dd.MM");

    Date date = inputDf.parse(input.substring(0,9));
    System.out.println(date);
    System.out.println(outputDf.format(date));
}