Kotlin DateTimeParseException - datetime

Question

Getting date from https://api.spacexdata.com/v3/launches
This date have format: 2006-03-25T10:30:00+12:00.
I want convert it to "dd, mm, yyyy", but always getting error:
"java.time.format.DateTimeParseException: Text '2006-03-25T10:30:00+12:00' could not be parsed, unparsed text found at index 10"
my code:
val formatter = DateTimeFormatter.ofPattern("dd, mm, yyyy", Locale.US)
val myDate = LocalDate.parse(launchDate, formatter)
var launchDateConverted: String= myDate.toString()
i getting data at String, then i convert it to date for formatting, and after i converting date back to string thats to display at UI. i used different methods, but cannot find the correct way.
My current locale is "RU".

Answer 1

You do not need any formatter to parse your input string
You input string, 2006-03-25T10:30:00+12:00 is already in the default format used by OffsetDateTime#parse and therefore, you do not need to use a formatter explicitly in order to parse your input date-time string.
m specifies the minute while M specifies the month
You have wrongly used m for the month for which the symbol is M. Check the documentation page to learn more about these symbols.
Prefer u to y
y specifies the year-of-era (era is specified as AD or BC) and is always a positive number whereas u specifies the year which is a signed (+/-) number. Normally, we do not use + sign to write a positive number but we always specify a negative number with a - sign. The same rule applies for a year. As long as you are going to use a year of the era, AD (which is mostly the case), both, y and u will give you the same number. However, the difference occurs when you use a year of the era, BC e.g. the year-of-era, 1 BC is specified as year, 0; the year-of-era, 2 BC is specified as year, -1 and so on. You can understand it better with the following demo:
import java.time.LocalDate;
import java.time.format.DateTimeFormatter;
public class Testing {
public static void main(String[] args) {
System.out.println(LocalDate.of(-1, 1, 1).format(DateTimeFormatter.ofPattern("u M d")));
System.out.println(LocalDate.of(-1, 1, 1).format(DateTimeFormatter.ofPattern("y M d")));
System.out.println(LocalDate.of(-1, 1, 1).format(DateTimeFormatter.ofPattern("yG M d")));
System.out.println();
System.out.println(LocalDate.of(0, 1, 1).format(DateTimeFormatter.ofPattern("u M d")));
System.out.println(LocalDate.of(0, 1, 1).format(DateTimeFormatter.ofPattern("y M d")));
System.out.println(LocalDate.of(0, 1, 1).format(DateTimeFormatter.ofPattern("yG M d")));
System.out.println();
System.out.println(LocalDate.of(1, 1, 1).format(DateTimeFormatter.ofPattern("u M d")));
System.out.println(LocalDate.of(1, 1, 1).format(DateTimeFormatter.ofPattern("y M d")));
System.out.println(LocalDate.of(1, 1, 1).format(DateTimeFormatter.ofPattern("yG M d")));
}
}
Output:
-1 1 1
2 1 1
2BC 1 1
0 1 1
1 1 1
1BC 1 1
1 1 1
1 1 1
1AD 1 1
Note: I've used Java to demonstrate the solution but it will also work in Kotlin.
The final solution:
import java.time.OffsetDateTime;
import java.time.format.DateTimeFormatter;
import java.util.Locale;
public class Main {
public static void main(String[] args) {
OffsetDateTime odt = OffsetDateTime.parse("2006-03-25T10:30:00+12:00");
System.out.println(odt);
// Format it into the desired pattern
DateTimeFormatter dtf = DateTimeFormatter.ofPattern("dd, MM, uuuu", Locale.US);
String formatted = dtf.format(odt);
System.out.println(formatted);
}
}
Output:
2006-03-25T10:30+12:00
25, 03, 2006
Learn more about the modern date-time API from Trail: Date Time.

Answer 2

Your formatter does not match the input format. Basically you need two formatters: one for input and one for output.
The format "dd, mm, yyyy" is wrong: mm stands for minute of hour, not for month. You should use "dd, MM, yyyy".
val launchDate = "2006-03-25T10:30:00+12:00"
val inputFormatter = DateTimeFormatter.ISO_DATE_TIME
val myDate = LocalDate.parse(launchDate, inputFormatter)
val outputFormatter = DateTimeFormatter.ofPattern("dd, MM, yyyy", Locale.US)
println(outputFormatter.format(myDate))