救命啊,小弟有难,请各位大侠帮帮忙,这里有一程序,看不明白,哪位大哥能否帮我注释一下,在此先谢了

JPanel monthPanel = new JPanel();
        yearMonthPanel.add(monthPanel, BorderLayout.EAST);
        monthPanel.setLayout(new BorderLayout());
        monthPanel.add(monthsLabel, BorderLayout.WEST);
        monthPanel.add(monthsComboBox, BorderLayout.CENTER);        daysModel = new AbstractTableModel() {
                public int getRowCount() {
                    return 7;
                }                public int getColumnCount() {
                    return 7;
                }                public Object getValueAt(int row, int column) {
                    if (row == 0) {
                        return getHeader(column);
                    }
                    row--;
                    Calendar calendar = (Calendar) MyCalendar.this.calendar.clone();
                    calendar.set(Calendar.DAY_OF_MONTH, 1);
                    int dayCount = calendar.getActualMaximum(Calendar.DAY_OF_MONTH);
                    int moreDayCount = calendar.get(Calendar.DAY_OF_WEEK) - 1;
                    int index = row * 7 + column;
                    int dayIndex = index - moreDayCount + 1;
                    if (index < moreDayCount || dayIndex > dayCount) {
                        return null;
                    } else {
                        return new Integer(dayIndex);
                    }
                }
            };        daysTable = new CalendarTable(daysModel, calendar);
        daysTable.setCellSelectionEnabled(true);
        daysTable.setSelectionMode(ListSelectionModel.SINGLE_SELECTION);        daysTable.setDefaultRenderer(daysTable.getColumnClass(0), new TableCellRenderer() {
                public Component getTableCellRendererComponent(JTable table, Object value, boolean isSelected,
                                                               boolean hasFocus, int row, int column) {
                    String text = (value == null) ? "" : value.toString();
                    JLabel cell = new JLabel(text);
                    cell.setOpaque(true);
                    if (row == 0) {
                        cell.setForeground(headerForeground);
                        cell.setBackground(headerBackground);
                    } else {
                        if (isSelected) {
                            cell.setForeground(selectedForeground);
                            cell.setBackground(selectedBackground);
                        } else {
                            cell.setForeground(foreground);
                            cell.setBackground(background);
                        }
                    }                    return cell;
                }
            });
        updateView();        cPane.add(daysTable, BorderLayout.CENTER);
    }    public static String getHeader(int index) {
        switch (index) {
        case 0:
            return WEEK_SUN;
        case 1:
            return WEEK_MON;
        case 2:
            return WEEK_TUE;
        case 3:
            return WEEK_WED;
        case 4:
            return WEEK_THU;
        case 5:
            return WEEK_FRI;
        case 6:
            return WEEK_SAT;
        default:
            return null;
        }
    }    public void updateView() {
        daysModel.fireTableDataChanged();
        daysTable.setRowSelectionInterval(calendar.get(Calendar.WEEK_OF_MONTH),
                                          calendar.get(Calendar.WEEK_OF_MONTH));
        daysTable.setColumnSelectionInterval(calendar.get(Calendar.DAY_OF_WEEK) - 1,
                                             calendar.get(Calendar.DAY_OF_WEEK) - 1);
    }    public static class CalendarTable extends JTable {        private Calendar calendar;        public CalendarTable(TableModel model, Calendar calendar) {
            super(model);
            this.calendar = calendar;
        }        public void changeSelection(int row, int column, boolean toggle, boolean extend) {
            super.changeSelection(row, column, toggle, extend);
            if (row == 0) {
                return;
            }
            Object obj = getValueAt(row, column);
            if (obj != null) {
                calendar.set(Calendar.DAY_OF_MONTH, ((Integer)obj).intValue());
            }
        }    }    public static void main(String[] args) {
        JFrame frame = new JFrame("Calendar Application");
        frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        MyCalendar myCalendar = new MyCalendar();
        myCalendar.init();
        frame.getContentPane().add(myCalendar);
        frame.setSize(240, 172);
        frame.show();
    }}