使用jCalendar

Question

我正在尝试以不同的颜色在JCalendar中设置特定日期，具体取决于数据库中是否对该日期有计划，该日期在数据库中存储为“ yyyy-MM-dd”在stackOverflow上也有类似的帖子，但我无法使其正常工作。

我不确定“ component [day] .setBackground（Color.green）”的工作方式，以及如何将其设置为仅在数据库中为其计划了日期的日期

    public void kalender() {
    Calendar cal = Calendar.getInstance();
    cal.set(Calendar.DAY_OF_MONTH, 1);
    int offset = cal.get(Calendar.DAY_OF_WEEK);
    int mon = kalender.getMonthChooser().getMonth() + 1;
    int yr = kalender.getYearChooser().getYear();
    JPanel jPanel = kalender.getDayChooser().getDayPanel();
    Component component[] = jPanel.getComponents();
    SimpleDateFormat format = new SimpleDateFormat("yyyy-MM-dd");
     String kalenderdatum = format.format(kalender.getDate());
     System.out.println(kalenderdatum);



    String sql2 = "SELECT DATUM FROM MOTE";
    try {
        Statement stmt = connection.createStatement();
        ResultSet rs = stmt.executeQuery(sql2);

        while (rs.next()) {
            String datumet = rs.getString("DATUM");



            String aret = datumet.substring(0, 4);
            int year = Integer.parseInt(aret);

            String manaden = datumet.substring(5,7);
            int month = Integer.parseInt(manaden);

            String dagen = datumet.substring(8,10);
            int day = Integer.parseInt(dagen);

            if(yr == year && mon == month)
            {

                component[day].setBackground(Color.green);
            }

            }


    } catch (Exception e) {
        JOptionPane.showMessageDialog(null, e);
    } finally {
        try {


        } catch (Exception e) {
            JOptionPane.showMessageDialog(null, e);
        }
    }
}