JCalendar sets to March 30 when February is chosen

Question

Code consists of just month and year can be chosen in jcalendar, by default the day is 30 and 28 for February, the issue comes when I choose February, automatically jcalendar sets to March 30; this is the code; it is in PropertyChange event of jcalendar.

Calendar cal = PFI.getCalendar();
int day = cal.get(Calendar.DAY_OF_MONTH);
int month = cal.get(Calendar.MONTH);
int year = cal.get(Calendar.YEAR);
if(month==1){
    cal.set(year, 1 , 28);
    PFI.setCalendar(cal);
}
else
{
    cal.set(year, month , 30);
    PFI.setCalendar(cal);
}

I recommend you don’t use `Calendar`. That class is poorly designed and long outdated. Instead use `LocalDate` from [java.time, the modern Java date and time API](https://docs.oracle.com/javase/tutorial/datetime/). Best if you can find a calendar UI component that supports java.time, they exist. Otherwise convert. — Ole V.V., May 03 '22 at 07:54
In either calendar, use named constants. Why not use `JMonthChooser` and `JYearChooser` side-by-side, maybe with a common listener? — Catalina Island, May 17 '22 at 15:57

score 1 · Answer 1 · answered May 18 '22 at 17:13

Combining the suggestions of @Ole V.V. and @Catalina Island, the fragment below illustrates JYearChooser and JMonthChooser in a GridLayout. A common listener then uses java.time to display the last day of the selected year and month.


JPanel panel = new JPanel(new GridLayout(1, 0));
JMonthChooser jmc = new JMonthChooser();
JYearChooser jyc = new JYearChooser();
JLabel label = new JLabel("Last day of month:");
label.setHorizontalAlignment(JLabel.RIGHT);
JTextField last = new JTextField(8);
label.setLabelFor(last);
PropertyChangeListener myListener = new PropertyChangeListener() {
    @Override
    public void propertyChange(PropertyChangeEvent e) {
        LocalDate ld = LocalDate.of(jyc.getYear(), jmc.getMonth() + 1, 1)
            .with(TemporalAdjusters.lastDayOfMonth());
        last.setText(ld.format(DateTimeFormatter.ISO_DATE));
    }
};
myListener.propertyChange(null);
jmc.addPropertyChangeListener("month", myListener);
jyc.addPropertyChangeListener("year", myListener);
panel.add(jyc);
panel.add(jmc);
panel.add(label);
panel.add(last);

JCalendar sets to March 30 when February is chosen

1 Answers1