String (dd-MM-yyyy HH:mm) to Date (yyyy-MM-dd HH:mm) | Java

Question

I have a string in "dd-MM-yyyy HH:mm" and need to convert it to a date object in the format "yyyy-MM-dd HH:mm".

Below is the code I'm using to convert

oldScheduledDate = "16-05-2011 02:00:00";
DateFormat formatter = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");
Date oldDate = (Date)formatter.parse(oldScheduledDate);

Now when I print oldDate, i get

Sat Nov 01 02:00:00 GMT 21 , which is completely wrong, what am I doing wrong here?

Answer 1

    String dateSample = "10-01-2010 21:10:05";

    String oldFormat = "dd-MM-yyyy HH:mm:ss";
    String newFormat = "yyyy-MM-dd HH:mm:ss";

    SimpleDateFormat sdf1 = new SimpleDateFormat(oldFormat);
    SimpleDateFormat sdf2 = new SimpleDateFormat(newFormat);


    try {
        System.out.println(sdf2.format(sdf1.parse(dateSample)));

    } catch (ParseException e) {
        // TODO Auto-generated catch block
        e.printStackTrace();
    }

Answer 2

"yyyy-MM-dd" doesn't even look the same as "16-05-2011". Hmm. Well, why not?

Hints:

1. DateFormat is very literal. It takes the format specified and uses it -- nothing fancy.
2. Process: Input Date String -> Convert(With Input Format) -> Date -> Convert(With Output Format) -> Output Date String
3. The code in the post contains an Output Format, but no Import Format.

Answer 3

A simple approach is to swap around the letters.

String s = "16-05-2011 02:00:00";
String newDate=s.substring(6,10)+s.substring(3,6)+'-'+s.substring(0,2)+s.substring(10);

Answer 4

you need to use formatter when you want to output formatted date

public static void main(String[] args) throws ParseException {
    String oldScheduledDate = "16-05-2011 02:00:00";
    DateFormat oldFormatter = new SimpleDateFormat("dd-MM-yyyy HH:mm:ss");
    DateFormat formatter = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");
    Date oldDate = (Date)oldFormatter .parse(oldScheduledDate);
    System.out.println(formatter.format(oldDate));
}