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I am having issue with formatting strings to dates to the format 'dd-MMM-yy'. Would anyone have any idea why its parsing strings to full format rather than 'dd-MMM-yy'.

String = 
["01-Dec-20","02-Dec-20","03-Dec-20","04-Dec-20","05-Dec-20","06-Dec-20","07-Dec-20","08-Dec-20","09-Dec-20","10-Dec-20","11-Dec-20","12-Dec-20","13-Dec-20","14-Dec-20","15-Dec-20","16-Dec-20","17-Dec-20","18-Dec-20","19-Dec-20","20-Dec-20","21-Dec-20","22-Dec-20","23-Dec-20","24-Dec-20","25-Dec-20","26-Dec-20","27-Dec-20","28-Dec-20","29-Dec-20","30-Dec-20","31-Dec-20"]

For date in the string I want to convert to Date with format 'dd-MMM-yy'

String dates = dateType.replace("\"", "").replace("[", "").replace("]", "");
        List<String> stringList = new ArrayList<String>(Arrays.asList(dates.split(",")));
        ArrayList<Date> dateList = new ArrayList<Date>();

        stringList.forEach(d -> {
            try {
                Date date = new SimpleDateFormat("dd-MMM-yy").parse(d);
                dateList.add(date);
            } catch (ParseException e) {
                e.printStackTrace();
            } 
        });

The date list converts the strings to :

[Tue Dec 01 00:00:00 UTC 2020, Wed Dec 02 00:00:00 UTC 2020, Thu Dec 03 00:00:00 UTC 2020, Fri Dec 04 00:00:00 UTC 2020, Sat Dec 05 00:00:00 UTC 2020... etc ```
annaM
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    The output you're showing is expected. When you print a `Date` object, it looks like that "full format", and not a different, arbitrary format. If you want to those dates to look like `dd-MMM-yy`, you have to use the formatter and convert them to strings in that format. A `Date` itself is not associated with any particular format. – ernest_k Dec 02 '20 at 20:03
  • Thanks @ernest_k for answering so quickly! So if I want to use the list in an sql query to search a date column, should the Date format work, or can I use the list of string formats? – annaM Dec 02 '20 at 20:08
  • Well, shouldn't you be using a prepared statement and calling `setDate`? It's been a while since I last did jdbc, but either that or that plus converting the date to java.sql.Date should work without you needing to convert the date to string (unless your database column is char-typed and not date/timestamp-typed) – ernest_k Dec 02 '20 at 20:10
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    I recommend you don’t use `SimpleDateFormat` and `Date`. Those classes are poorly designed and long outdated, the former in particular notoriously troublesome. Instead use `LocalDate` and `DateTimeFormatter`, both from [java.time, the modern Java date and time API](https://docs.oracle.com/javase/tutorial/datetime/). For an SQL query pass your `LocalDate` to one of the `PreparedStatement.setObject` methods (no need to worry about format). – Ole V.V. Dec 02 '20 at 20:17
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    And @ernest_k, my recommendation to avoid `Date` goes for both `java.util.Date` and `java.sql.Date` (the latter being a hack on top of the former). – Ole V.V. Dec 02 '20 at 20:20
  • @OleV.V. Of course your suggestions are valid and on point. But the input the OP needed the most was that there's a difference between a date object and its string representation; and that goes irrespective of what date/time API is used. – ernest_k Dec 03 '20 at 05:39

0 Answers0