Converting MySQL date format in Java

Question

I am touching Java for the very first time here, so go easy on me. I am having to correct someone else's older code. This java program takes data from a MySQL table and prepares it for presentation on web pages. I found that their MySQL table for some reason used INT fields for all the dates. So, for instance, today's date is stored as the INT 3222017. I first had to add the proper DATE columns to the MySQL table. Next I re-did another Java script to pull the data from a larger table for the MySQL table that this script will be using.

Now I need to change the code that currently formats the INT fields into MM/dd/yyyy to instead take the DATE fields (stored as yyyy-MM-dd) and convert them to the same MM/dd/yyyy.

Here is a piece of the code that uses the function dateFormat on the INT fields -

String formattedDate = "";

            formattedDate = dateFormat(oneSpectro.getSpectroLastDate());
            result.setSpectroLastDate(formattedDate);

            formattedDate = dateFormat(oneSpectro.getSpectroOrigDate());
            result.setSpectroOrigDate(formattedDate);

            formattedDate = dateFormat(oneSpectro.getSpectroCalDate());
            result.setSpectroCalDate(formattedDate);
            }

        return result;
    }

And here is the dateFormat function -

public String dateFormat(int theDate){
        String      dateString = "";
        Integer     dateInt = 0;

        if (theDate < 10000000){
            dateInt = new Integer(theDate);
            dateString = dateInt.toString();
            // Add preceding 0 to make the date 8 digits in length.
            dateString  = "0" + dateString;

        }
        else {
            // Process an 8 digit date.
            dateInt = new Integer(theDate);
            dateString = dateInt.toString();
        }
        // Install date slashes in the date string.
        if (dateString.length() == 8){
            dateString = dateString.substring(0, 2) + "/" + dateString.substring(2, 4) + "/" 
                    + dateString.substring(4);
        }
        return dateString;
    }

How do I go about converting a DATE field (yyyy-MM-dd) to a formatted date of MM/dd/yyyy?

Answer 1

You can convert String to Date util:

 DateFormat format = new SimpleDateFormat("yyyy-MM-dd", Locale.ENGLISH);
 Date date = format.parse(your string);

And then convert the Date object to your String format:

 DateFormat df = new SimpleDateFormat("MM/dd/yyyy");
 String result = df.format(date);