Concatenating or formatting JComboBox Year, Month, Day integer values to Date type

Question

I have put the year, month, day on separate JComboBoxes Month JComboBox has it's own renderer to display month names instead of integer value of month. Where month begins at 0 (0-January....11-December)

So, my problem is how I can put the year, month, day together and assign it to a Date data type.

I tried concatenating year, month, day together to a String variable

int startYear = Integer.parseInt(jcmbFirstSemStartDateYear.getSelectedItem().toString() );
int startMonth = Integer.parseInt(jcmbFirstSemStartDateMonth.getSelectedItem().toString() );
int startDay = Integer.parseInt(jcmbFirstSemStartDateDay.getSelectedItem().toString() );

String startDate = startYear+"-"+startMonth+"-"+startDay; //not sure if this okay
Date completeStartDate = java.sql.Date.valueOf(startDate);
JOptionPane.showMessageDialog(null,completeStartDate);

hasConflict(completeStartDate, completeEndDate); //method to check conflict

But when I printed the value of completeStartDate, it displayed the month of February as 01.

I'm worried that this might be read as January instead of February when I extract the month to check for conflicts.

    public static boolean hasConflict(Date aStartDate, Date aEndDate){
        boolean hasConflict = false;
        Calendar calStart = Calendar.getInstance();
        calStart.setTime(aStartDate);
        int startYear = calStart.get(Calendar.YEAR);
        int startMonth = calStart.get(Calendar.MONTH); //extract month
        int startDay = calStart.get(Calendar.DAY_OF_MONTH);
        // ... if else conditions to compare startDate with endDate
        return hasConflict;
    }

Later on, I'll store these dates to mysql database.

Any thoughts or advice?

Thank you.

You could create a String representation and then parse it based on the format, or you could use LocalDate.of(year, month, dayOfMonth) — MadProgrammer

MadProgrammer MadProgrammer · Accepted Answer · 2017-03-08T10:18:54

If possible you should probably use LocalDate.of(year, month, dayOfMonth)

LocalDate date = LocalDate.of(startYear, startMonth, startDay);

At a stretch you could create a String representation and parse it

String dateValue = startYear + "/" + startMonth + "/" + startDay;
SimpleDateFormat sdf = new SimpleDateFormat("yyyy/MM/dd");
Date data = sdf.parse(dateValue);

But given the simplicity of LocalDate, I'd go for that ... besides, if you're using Java 8 and above, you shouldn't really be using java.util.Date where you can and even if you're not, I'd consider JodaTime over java.util.Date anyway

Concatenating or formatting JComboBox Year, Month, Day integer values to Date type

1 Answers