Java实现Map集合二级联动示例

import java.awt.Graphics;
import java.awt.Image;
 
import javax.swing.JPanel;
 
/**
 * 带背景的面板组件
 *
 * @author ZhongWei Lee
 */
public class BackgroundPanel extends JPanel {
 
    /**
     *
     */
    private static final long serialVersionUID = 7758689434195492602L;
    /**
     * 背景图片
     */
    private Image image;
 
    /**
     * 构造方法
     */
    public BackgroundPanel() {
        super();
        setOpaque(false);
        setLayout(null);
    }
 
    /**
     * 设置图片的方法
     */
    public void setImage(Image image) {
        this.image = image;
    }
 
    @Override
    protected void paintComponent(Graphics g) {// 重写绘制组件外观
        if (image != null) {
            int width = getWidth();// 获取组件大小
            int height = getHeight();
            g.drawImage(image, 0, 0, width, height, this);// 绘制图片与组件大小相同
        }
        super.paintComponent(g);// 执行超类方法
    }
}

import java.awt.Image;
import java.awt.Toolkit;
import java.io.BufferedInputStream;
import java.io.ByteArrayOutputStream;
import java.io.FileInputStream;
import java.io.IOException;
import java.io.InputStream;
import java.util.HashMap;
import java.util.Iterator;
import javax.swing.ImageIcon;
 
/**
 * Utility class for managing resources such as colors, fonts, images, etc.
 *
 * This class may be freely distributed as part of any application or plugin.
 * <p>
 * Copyright (c) 2003 - 2004, Instantiations, Inc. <br>All Rights Reserved
 *
 * @author scheglov_ke
 */
public class SwingResourceManager {
    
    /**
     * Maps image names to images
     */
    private static HashMap<String, Image> m_ClassImageMap = new HashMap<String, Image>();
    
    /**
     * Returns an image encoded by the specified input stream
     * @param is InputStream The input stream encoding the image data
     * @return Image The image encoded by the specified input stream
     */
    private static Image getImage(InputStream is) {
        try {
            ByteArrayOutputStream baos = new ByteArrayOutputStream();
            byte buf[] = new byte[1024 * 4];
            while (true) {
                int n = is.read(buf);
                if (n == -1)
                    break;
                baos.write(buf, 0, n);
            }
            baos.close();
            return Toolkit.getDefaultToolkit().createImage(baos.toByteArray());
        } catch (Throwable e) {
            return null;
        }
    }
    
    /**
     * Returns an image stored in the file at the specified path relative to the specified class
     * @param clazz Class The class relative to which to find the image
     * @param path String The path to the image file
     * @return Image The image stored in the file at the specified path
     */
    public static Image getImage(Class<?> clazz, String path) {
        String key = clazz.getName() + '|' + path;
        Image image = m_ClassImageMap.get(key);
        if (image == null) {
            if ((path.length() > 0) && (path.charAt(0) == '/')) {
                String newPath = path.substring(1, path.length());
                image = getImage(new BufferedInputStream(clazz.getClassLoader().getResourceAsStream(newPath)));
            } else {
                image = getImage(clazz.getResourceAsStream(path));
            }
            m_ClassImageMap.put(key, image);
        }
        return image;
    }
    
    /**
     * Returns an image stored in the file at the specified path
     * @param path String The path to the image file
     * @return Image The image stored in the file at the specified path
     */
    public static Image getImage(String path) {
        return getImage("default", path); //$NON-NLS-1$
    }
    
    /**
     * Returns an image stored in the file at the specified path
     * @param section String The storage section in the cache
     * @param path String The path to the image file
     * @return Image The image stored in the file at the specified path
     */
    public static Image getImage(String section, String path) {
        String key = section + '|' + SwingResourceManager.class.getName() + '|' + path;
        Image image = m_ClassImageMap.get(key);
        if (image == null) {
            try {
                FileInputStream fis = new FileInputStream(path);
                image = getImage(fis);
                m_ClassImageMap.put(key, image);
                fis.close();
            } catch (IOException e) {
                return null;
            }
        }
        return image;
    }
    
    /**
     * Clear cached images in specified section
     * @param section the section do clear
     */
    public static void clearImages(String section) {
        for (Iterator<String> I = m_ClassImageMap.keySet().iterator(); I.hasNext();) {
            String key = I.next();
            if (!key.startsWith(section + '|'))
                continue;
            Image image = m_ClassImageMap.get(key);
            image.flush();
            I.remove();
        }
    }
    
    /**
     * Returns an icon stored in the file at the specified path relative to the specified class
     * @param clazz Class The class relative to which to find the icon
     * @param path String The path to the icon file
     * @return Icon The icon stored in the file at the specified path
     */
    public static ImageIcon getIcon(Class<?> clazz, String path) {
        return getIcon(getImage(clazz, path));
    }
    
    /**
     * Returns an icon stored in the file at the specified path
     * @param path String The path to the icon file
     * @return Icon The icon stored in the file at the specified path
     */
    public static ImageIcon getIcon(String path) {
        return getIcon("default", path); //$NON-NLS-1$
    }
    
    /**
     * Returns an icon stored in the file at the specified path
     * @param section String The storage section in the cache
     * @param path String The path to the icon file
     * @return Icon The icon stored in the file at the specified path
     */
    public static ImageIcon getIcon(String section, String path) {
        return getIcon(getImage(section, path));
    }
 
    /**
     * Returns an icon based on the specified image
     * @param image Image The original image
     * @return Icon The icon based on the image
     */
    public static ImageIcon getIcon(Image image) {
        if (image == null)
            return null;
        return new ImageIcon(image);
    }
}

import java.awt.EventQueue;
import java.awt.event.ItemEvent;
import java.awt.event.ItemListener;
import java.util.Map;
import java.util.Set;
 
import javax.swing.DefaultComboBoxModel;
import javax.swing.JButton;
import javax.swing.JComboBox;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JPanel;
import javax.swing.JTextField;
import javax.swing.SwingConstants;
import javax.swing.UIManager;
import javax.swing.border.TitledBorder;
 
 
public class MainFrame extends JFrame {
 
    /**
     *
     */
    private static final long serialVersionUID = -4595347311922711984L;
    private JTextField textField_3;
    private JTextField textField_1;
    private JComboBox comboBox_1;
    private JTextField textField;
    private JComboBox cityComboBox;
    private JComboBox comboBox;
 
    /**
     * Launch the application
     *
     * @param args
     */
    public static void main(String args[]) {
        EventQueue.invokeLater(new Runnable() {
            public void run() {
                try {
                    UIManager.setLookAndFeel("com.sun.java.swing.plaf.nimbus.NimbusLookAndFeel");
                    MainFrame frame = new MainFrame();
                    frame.setVisible(true);
                } catch (Exception e) {
                    e.printStackTrace();
                }
            }
        });
    }
 
    /**
     * Create the frame
     */
    public MainFrame() {
        getContentPane().setLayout(null);
        setBounds(100, 100, 518, 379);
        setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        //获取默认的市/县
        String province=(String)getProvince()[0];
        setTitle("输入指定省/直辖市查询对应的市县");
 
        final BackgroundPanel backgroundPanel = new BackgroundPanel();
        backgroundPanel.setImage(SwingResourceManager.getImage(MainFrame.class, "/images/background.jpg"));
        backgroundPanel.setBounds(0, 0, 510, 380);
        getContentPane().add(backgroundPanel);
 
        final JPanel panel = new JPanel();
        panel.setOpaque(false);
        panel.setBounds(36, 126, 438, 70);
        backgroundPanel.add(panel);
        panel.setLayout(null);
        panel.setBorder(new TitledBorder(null, "居住地", TitledBorder.DEFAULT_JUSTIFICATION, TitledBorder.DEFAULT_POSITION, null, null));
        cityComboBox = new JComboBox();
        cityComboBox.setBounds(245, 25, 124, 27);
        panel.add(cityComboBox);
        
        cityComboBox.setModel(new DefaultComboBoxModel(getCity(province)));
 
        comboBox = new JComboBox();
        comboBox.setBounds(25, 25, 124, 27);
        panel.add(comboBox);
        comboBox.addItemListener(new ItemListener() {
            public void itemStateChanged(final ItemEvent e) { // 选项状态更改事件
                itemChange();
            }
        });
        comboBox.setModel(new DefaultComboBoxModel(getProvince())); // 添加省份信息
 
        final JLabel label = new JLabel();
        label.setText("省/直辖市");
        label.setBounds(155, 30, 66, 18);
        panel.add(label);
 
        final JLabel label_1 = new JLabel();
        label_1.setText("市/县");
        label_1.setBounds(375, 30, 37, 18);
        panel.add(label_1);
 
        final JLabel label_2 = new JLabel();
        label_2.setBounds(36, 43, 65, 18);
        backgroundPanel.add(label_2);
        label_2.setHorizontalAlignment(SwingConstants.RIGHT);
        label_2.setHorizontalTextPosition(SwingConstants.LEADING);
        label_2.setText("姓    名：");
 
        textField = new JTextField();
        textField.setBounds(113, 38, 154, 28);
        backgroundPanel.add(textField);
 
        final JLabel label_3 = new JLabel();
        label_3.setBounds(36, 84, 65, 18);
        backgroundPanel.add(label_3);
        label_3.setHorizontalAlignment(SwingConstants.RIGHT);
        label_3.setHorizontalTextPosition(SwingConstants.LEADING);
        label_3.setText("性    别：");
 
        comboBox_1 = new JComboBox();
        comboBox_1.setBounds(113, 81, 66, 25);
        backgroundPanel.add(comboBox_1);
        comboBox_1.setModel(new DefaultComboBoxModel(new String[] {"男", "女"}));
 
        final JLabel label_4 = new JLabel();
        label_4.setBounds(36, 212, 65, 18);
        backgroundPanel.add(label_4);
        label_4.setHorizontalAlignment(SwingConstants.RIGHT);
        label_4.setHorizontalTextPosition(SwingConstants.LEADING);
        label_4.setText("详细地址：");
 
        textField_1 = new JTextField();
        textField_1.setBounds(113, 208, 367, 28);
        backgroundPanel.add(textField_1);
 
        final JLabel label_4_1 = new JLabel();
        label_4_1.setBounds(36, 252, 65, 18);
        backgroundPanel.add(label_4_1);
        label_4_1.setHorizontalTextPosition(SwingConstants.LEADING);
        label_4_1.setHorizontalAlignment(SwingConstants.RIGHT);
        label_4_1.setText("E-mail：");
 
        textField_3 = new JTextField();
        textField_3.setBounds(113, 248, 367, 27);
        backgroundPanel.add(textField_3);
 
        final JButton button = new JButton();
        button.setBounds(159, 289, 75, 28);
        backgroundPanel.add(button);
        button.setText("保存");
 
        final JButton button_1 = new JButton();
        button_1.setBounds(265, 289, 75, 28);
        backgroundPanel.add(button_1);
        button_1.setText("重置");
        //
    }
 
    /**
     * 获取省、直辖市，自治区
     *
     * @return
     */
    public Object[] getProvince() {
        Map<String, String[]> map = CityMap.model;// 获取省份信息保存到Map中
        Set<String> set = map.keySet(); // 获取Map集合中的键，并以Set集合返回
        Object[] province = set.toArray(); // 转换为数组
        return province; // 返回获取的省份信息
    }
 
    /**
     * 获取指定省对应的市/县
     *
     * @param selectProvince
     * @return
     */
    public String[] getCity(String selectProvince) {
        Map<String, String[]> map = CityMap.model; // 获取省份信息保存到Map中
        String[] arrCity = map.get(selectProvince); // 获取指定键的值
        return arrCity; // 返回获取的市/县
    }
 
    private void itemChange() {
        String selectProvince = (String) comboBox.getSelectedItem();
        cityComboBox.removeAllItems(); // 清空市/县列表
        String[] arrCity = getCity(selectProvince); // 获取市/县
        cityComboBox.setModel(new DefaultComboBoxModel(arrCity)); // 重新添加市/县列表的值
    }
 
}