Question

I thinking what is the best way in Java to parse the String with this format
dd/MM/yyyy [to dd/MM/yyyy]. The string with the [] are optional and dd stand for the 2 digit presentation of dates, MM is the 2 digit presentation of month and yyyy is the 4 digit presentation of year.

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Update

Thanks guys for the fast response, however I forgot to tell you the [] is to symbolize optional, there is no [] in the string a sample String might be

• 22/01/2010
• 22/01/2010 to 23/01/2010
• null

Current I wrote the code this way, work but is ugly =(

String _daterange = (String) request.getParameter("daterange");
    Date startDate = null, endDate = null;
    // Format of incoming dateRange is 
    if (InputValidator.requiredValidator(_daterange)) {
        String[] _dateRanges = _daterange.toUpperCase().split("TO");
        try {
            startDate = (_dateRanges.length > 0) ? sdf.parse(_dateRanges[0]) : null;
            try{
                endDate = (_dateRanges.length > 1) ? sdf.parse(_dateRanges[1]) : null;
            }catch(Exception e){
                endDate = null;
            }
        } catch (Exception e) {
            startDate = null;
        }
    }

Answer 1

Use java.text.DateFormat and java.text.SimpleDateFormat to do it.

DateFormat sourceFormat = new SimpleDateFormat("dd/MM/yyyy");
String dateAsString = "25/12/2010";
Date date = sourceFormat.parse(dateAsString);

UPDATE:

If you have two Dates hiding in that String, you’ll have to break them into two parts. I think others have pointed out the “split” idea. I’d just break at whitespace and throw the “TO” away.

Don’t worry about efficiency. Your app is likely to be riddled with inefficiencies much worse than this. Make it work correctly and refactor it only if profiling tells you that this snippet is the worst offender.