// Before Java8 , No thread safe , has to import multiple packages(util, text), throws checked Exception(ParseException)
System.out.println(oldDate); //21 Jul 2019
SimpleDateFormat oldPattern = new SimpleDateFormat("dd MMM yyyy");
SimpleDateFormat newPattern = new SimpleDateFormat("dd-MM-yyyy");
try {
Date date = oldPattern.parse(oldDate);
String newDate = newPattern.format(date);
System.out.println(newDate); //21-07-2019
} catch (ParseException e) {
// Exception handling message/mechanism/logging as per company standard
}
// In Java8, Thread Safe, Immutable, throws unchecked Exception(DateTimeParseException)
DateTimeFormatter oldPattern8 = DateTimeFormatter.ofPattern("dd MMM-yyyy");
DateTimeFormatter newPattern8 = DateTimeFormatter.ofPattern("dd-MM-yyyy");
LocalDate datetime = LocalDate.parse(oldDate, oldPattern8);
String output = datetime.format(newPattern8);
System.out.println(output); //21-07-2019