java jframe 城市三级联动

public class Sanji extends JFrame {private JPanel contentPane;private JComboBox shengBox;private JComboBox shiboBox;private String[] shengarr;//存放省份ProID的map集合private Map<String, Integer> proidmap=new HashMap<String, Integer>();     //存放市cityID的集合private Map<String, Integer> citymap=new HashMap<String,Integer>();private String[] shiarr;//市数组private JComboBox comboBox;private JLabel label_2;private String[] quarr;//区数组/** * Launch the application. */public static void main(String[] args) {EventQueue.invokeLater(new Runnable() {public void run() {try {Sanji frame = new Sanji();frame.setVisible(true);} catch (Exception e) {e.printStackTrace();}}});}/** * Create the frame. */public Sanji() {getsheng();setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);setBounds(100, 100, 450, 300);contentPane = new JPanel();contentPane.setBorder(new EmptyBorder(5, 5, 5, 5));setContentPane(contentPane);contentPane.setLayout(null);shengBox = new JComboBox();//省份的监听事件shengBox.addActionListener(new ActionListener() {public void actionPerformed(ActionEvent arg0) {   String cityname=(String) shengBox.getSelectedItem();//获得省份框对象   int id=proidmap.get(cityname);   getshi(id);//调用获得市的方法   shiboBox.setModel(new DefaultComboBoxModel(shiarr));//向市下拉框添加数据}});shengBox.setModel(new DefaultComboBoxModel(shengarr));shengBox.setBounds(10, 31, 76, 21);contentPane.add(shengBox);JLabel label = new JLabel("\u7701");label.setBounds(96, 34, 54, 15);contentPane.add(label);//市的监听事件shiboBox = new JComboBox();shiboBox.addActionListener(new ActionListener() {public void actionPerformed(ActionEvent arg0) {String str=(String) shiboBox.getSelectedItem();int id=citymap.get(str);getqu(id);comboBox.setModel(new DefaultComboBoxModel(quarr));}});shiboBox.setBounds(135, 31, 76, 21);contentPane.add(shiboBox);JLabel label_1 = new JLabel("\u5E02");label_1.setBounds(221, 34, 54, 15);contentPane.add(label_1);comboBox = new JComboBox();comboBox.setBounds(280, 31, 63, 21);contentPane.add(comboBox);label_2 = new JLabel("\u533A");label_2.setBounds(353, 34, 54, 15);contentPane.add(label_2);}//获得省public void getsheng(){try {JsonParser jp =new JsonParser();FileReader fr =new FileReader("city.json");//json文件JsonObject jo=(JsonObject) jp.parse(fr);JsonArray sheng =jo.get("省").getAsJsonArray();shengarr=new String[sheng.size()];for (int i = 0; i < sheng.size(); i++) {JsonObject jo2=(JsonObject) sheng.get(i);String name=jo2.get("name").getAsString();int proid=jo2.get("ProID").getAsInt();shengarr[i]=name;proidmap.put(name, proid);}} catch (Exception e) {e.printStackTrace();}}//获得市public void getshi(int proid){JsonParser jp =new JsonParser();try {FileReader fr =new FileReader("city.json");JsonObject jo=(JsonObject) jp.parse(fr);JsonArray shi =jo.get("市").getAsJsonArray();shengarr=new String[shi.size()];StringBuffer sb=new StringBuffer();for (int i = 0; i < shi.size(); i++) {JsonObject jo2=(JsonObject) shi.get(i);int id=jo2.get("ProID").getAsInt();int cityid=jo2.get("CityID").getAsInt();String cityname=jo2.get("name").getAsString();citymap.put(cityname, cityid);if(id==proid){String shiname=jo2.get("name").getAsString();sb.append(shiname+",");}}shiarr=sb.toString().split(",");} catch (Exception e) {e.printStackTrace();}}//获得区的方法public void getqu(int id){try {JsonParser jp =new JsonParser();FileReader fr =new FileReader("city.json");JsonObject jo=(JsonObject) jp.parse(fr);JsonArray qu =jo.get("区").getAsJsonArray();shengarr=new String[qu.size()];StringBuffer sb=new StringBuffer();for (int i = 0; i < qu.size(); i++) {JsonObject jo2=(JsonObject) qu.get(i);int cityid=jo2.get("CityID").getAsInt();if(cityid==id){String name=jo2.get("DisName").getAsString();sb.append(name+",");}}quarr=sb.toString().split(",");} catch (Exception e) {e.printStackTrace();}}}