Jcombobox添加點擊事件監聽

final JComboBox comboBox_6 = new JComboBox();           //創建combobox對象
comboBox_6.setBounds(470, 10, 44, 23);
comboBox_6.setSelectedIndex(DD1-1);
        comboBox_5.addItemListener(new ItemListener()        //添加監聽事件
        {
            @Override
            public void itemStateChanged(ItemEvent e){        //通過監聽combobox中值的改變，獲得改變后的索引值
                
                if(list1.contains(comboBox_5.getSelectedItem())){
                     System.out.println("123");
                     comboBox_6.setModel(new DefaultComboBoxModel(day));
                     System.out.println(comboBox_5.getSelectedItem());
                     System.out.println(new DefaultComboBoxModel(day));            //combobox的setModel方法是創建或者改變combobox的索引列表
                     
                }
                if(list2.contains(comboBox_5.getSelectedItem())){
                     System.out.println("123");
        
                     if( YY1%4 == 0){
                         comboBox_6.setModel(new DefaultComboBoxModel(day2));
                         System.out.println(comboBox_5.getSelectedItem());
                         System.out.println(new DefaultComboBoxModel(day2));

                     }else{
                         comboBox_6.setModel(new DefaultComboBoxModel(day3));
                         System.out.println(comboBox_5.getSelectedItem());
                         System.out.println(new DefaultComboBoxModel(day3));
                     }
                
                     
                }
                if(list3.contains(comboBox_5.getSelectedItem())){
                     System.out.println("123");
                     comboBox_6.setModel(new DefaultComboBoxModel(day1));
                     System.out.println(comboBox_5.getSelectedItem());
                     System.out.println(new DefaultComboBoxModel(day1));
                     
                }

            }
        });