Java基础知识：Java实现Map集合二级联动3

* 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 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);

　　}

　　}

　　MainFrame.java

　　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");