import java.awt.event.*;

 import javax.swing.*;

 /**

  * A frame with a sample menu bar.

  */

 public class MenuFrame extends JFrame

 {

    private static final int DEFAULT_WIDTH = ;

    private static final int DEFAULT_HEIGHT = ;

    private Action saveAction;

    private Action saveAsAction;

    private JCheckBoxMenuItem readonlyItem;

    private JPopupMenu popup;

    /**

     * A sample action that prints the action name to System.out.

     */

    class TestAction extends AbstractAction

    {

       public TestAction(String name)

       {

          super(name);

       }

       public void actionPerformed(ActionEvent event)

       {

          System.out.println(getValue(Action.NAME) + " selected.");

       }

    }

    public MenuFrame()

    {

       setSize(DEFAULT_WIDTH, DEFAULT_HEIGHT);//设置菜单框架的大小

       JMenu fileMenu = new JMenu("File");

       fileMenu.add(new TestAction("New"));

       // 演示加速器

       JMenuItem openItem = fileMenu.add(new TestAction("Open"));  //

       openItem.setAccelerator(KeyStroke.getKeyStroke("ctrl O"));  //将加速器ctrl O关联到openItem菜单项

       fileMenu.addSeparator();  //在fileMenu菜单中添加分隔符

       saveAction = new TestAction("Save");

       JMenuItem saveItem = fileMenu.add(saveAction);

       saveItem.setAccelerator(KeyStroke.getKeyStroke("ctrl S"));   //将加速器ctrl S关联到saveItem菜单项

       saveAsAction = new TestAction("Save As");

       fileMenu.add(saveAsAction);

       fileMenu.addSeparator();

       fileMenu.add(new AbstractAction("Exit")

          {

             public void actionPerformed(ActionEvent event)

             {

                System.exit();

             }

          });

       // 演示复选框和单选按钮菜单

       readonlyItem = new JCheckBoxMenuItem("Read-only");  //用Read-only构造一个复选框菜单项

       readonlyItem.addActionListener(new ActionListener()

          {

             public void actionPerformed(ActionEvent event)

             {

                boolean saveOk = !readonlyItem.isSelected();  //获取菜单项的选择状态

                saveAction.setEnabled(saveOk);  //启用菜单项

                saveAsAction.setEnabled(saveOk);

             }

          });

       ButtonGroup group = new ButtonGroup();  //为单选钮组构造一个对象

       JRadioButtonMenuItem insertItem = new JRadioButtonMenuItem("Insert");//创建一个单选按钮

       insertItem.setSelected(true); //设置这个菜单的选择状态

       JRadioButtonMenuItem overtypeItem = new JRadioButtonMenuItem("Overtype");  

       group.add(insertItem);//把insertItem对象加到按钮组中

       group.add(overtypeItem);

       // 演示图标 

       TestAction cutAction = new TestAction("Cut");

       cutAction.putValue(Action.SMALL_ICON, new ImageIcon("cut.gif"));

       TestAction copyAction = new TestAction("Copy");

       copyAction.putValue(Action.SMALL_ICON, new ImageIcon("copy.gif"));

       TestAction pasteAction = new TestAction("Paste");

       pasteAction.putValue(Action.SMALL_ICON, new ImageIcon("paste.gif"));

       JMenu editMenu = new JMenu("Edit");

       editMenu.add(cutAction);

       editMenu.add(copyAction);

       editMenu.add(pasteAction);

       // 演示嵌套菜单

       JMenu optionMenu = new JMenu("Options");

       optionMenu.add(readonlyItem);

       optionMenu.addSeparator();

       optionMenu.add(insertItem);

       optionMenu.add(overtypeItem);

       editMenu.addSeparator();

       editMenu.add(optionMenu);//把optionMenu菜单嵌套在edit菜单中

       // 演示助记符

       JMenu helpMenu = new JMenu("Help");

       helpMenu.setMnemonic('H');  //为Help这个菜单设置快捷键H

       JMenuItem indexItem = new JMenuItem("Index");

       indexItem.setMnemonic('I');  //为Help这个菜单设置快捷键I

       helpMenu.add(indexItem);//将Index菜单项添加到Help这个菜单中

       //也可以将助记键添加到动作中

       TestAction aboutAction = new TestAction("About");

       aboutAction.putValue(Action.MNEMONIC_KEY, new Integer('A')); //为aboutAction对象添加快捷键A

       helpMenu.add(aboutAction);

       // 将所有顶级菜单添加到菜单栏

       JMenuBar menuBar = new JMenuBar();//创建一个菜单栏

       setJMenuBar(menuBar);

       menuBar.add(fileMenu);

       menuBar.add(editMenu);

       menuBar.add(helpMenu);

       // 演示弹出窗口

       popup = new JPopupMenu();  //创建一个弹出菜单

       popup.add(cutAction);

       popup.add(copyAction);

       popup.add(pasteAction);

       JPanel panel = new JPanel();

       panel.setComponentPopupMenu(popup);  //用户点击panel时弹出菜单

       add(panel);

    }

 }

 import java.awt.*;

 import javax.swing.*;

 /**

  * @version 1.25 2018-04-10

  * @author Cay Horstmann

  */

 public class MenuTest

 {

    public static void main(String[] args)

    {

       EventQueue.invokeLater(() -> {

          MenuFrame frame = new MenuFrame();

          frame.setTitle("MenuTest");

          frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);

          frame.setVisible(true);

       });

    }

 }

 import java.awt.*;

 import java.awt.event.*;

 import javax.swing.*;

 /**

  * 带有工具栏和颜色变化菜单的框架

  */

 public class ToolBarFrame extends JFrame

 {

    private static final int DEFAULT_WIDTH = ;

    private static final int DEFAULT_HEIGHT = ;

    private JPanel panel;

    public ToolBarFrame()

    {

       setSize(DEFAULT_WIDTH, DEFAULT_HEIGHT);

       // 添加用于颜色更改的面板

       panel = new JPanel();

       add(panel, BorderLayout.CENTER);//将这个面板加在边框的中间

       // 设置操作

       ColorAction blueAction = new ColorAction("Blue", new ImageIcon("blue-ball.gif"), Color.BLUE);

       ColorAction yellowAction = new ColorAction("Yellow", new ImageIcon("yellow-ball.gif"),Color.YELLOW);

       ColorAction redAction = new ColorAction("Red", new ImageIcon("red-ball.gif"), Color.RED);

       AbstractAction exitAction = new AbstractAction("Exit", new ImageIcon("exit.gif"))

          {

             public void actionPerformed(ActionEvent event)

             {

                System.exit();

             }

          };

       exitAction.putValue(Action.SHORT_DESCRIPTION, "Exit");

       // 填充工具栏

       JToolBar bar = new JToolBar();  //创建一个工具栏

       bar.add(blueAction);

       bar.add(yellowAction);

       bar.add(redAction);

       bar.addSeparator();  //给工具栏添加分隔符

       bar.add(exitAction);

       add(bar, BorderLayout.NORTH);

       //填充菜单

       JMenu menu = new JMenu("Color");

       menu.add(yellowAction);

       menu.add(blueAction);

       menu.add(redAction);

       menu.add(exitAction);

       JMenuBar menuBar = new JMenuBar();//创建菜单栏

       menuBar.add(menu);//将菜单栏加到菜单上

       setJMenuBar(menuBar);

    }

    /**

     * 颜色动作将框架的背景设置为给定的颜色.

     */

    class ColorAction extends AbstractAction

    {

       public ColorAction(String name, Icon icon, Color c)

       {

          putValue(Action.NAME, name);

          putValue(Action.SMALL_ICON, icon);

          putValue(Action.SHORT_DESCRIPTION, name + " background");

          putValue("Color", c);

       }

       public void actionPerformed(ActionEvent event)

       {

          Color c = (Color) getValue("Color");

          panel.setBackground(c);  //给面板加背景

       }

    }

 }

 import java.awt.*;

 import javax.swing.*;

 /**

  * @version 1.15 2018-04-10

  * @author Cay Horstmann

  */

 public class ToolBarTest

 {

    public static void main(String[] args)

    {

       EventQueue.invokeLater(() -> {

          ToolBarFrame frame = new ToolBarFrame();

          frame.setTitle("ToolBarTest");

          frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);

          frame.setVisible(true);

       });

    }

 }

 import java.awt.*;

 import java.awt.event.*;

 import java.awt.geom.*;

 import java.awt.geom.Rectangle2D.Double;

 import java.util.*;

 import javax.swing.*;

 /**

  * 包含用于选择各种选项对话框的设置的框架。

  */

 public class OptionDialogFrame extends JFrame

 {

    private ButtonPanel typePanel;

    private ButtonPanel messagePanel;

    private ButtonPanel messageTypePanel;

    private ButtonPanel optionTypePanel;

    private ButtonPanel optionsPanel;

    private ButtonPanel inputPanel;

    private String messageString = "Message";

    private Icon messageIcon = new ImageIcon("blue-ball.gif");

    private Object messageObject = new Date();

    private Component messageComponent = new SampleComponent();

    public OptionDialogFrame()

    {

       JPanel gridPanel = new JPanel();

       gridPanel.setLayout(new GridLayout(, ));//设置该面板的布局管理器为2行3列的网格

       typePanel = new ButtonPanel("Type", "Message", "Confirm", "Option", "Input");

       messageTypePanel = new ButtonPanel("Message Type", "ERROR_MESSAGE", "INFORMATION_MESSAGE",

             "WARNING_MESSAGE", "QUESTION_MESSAGE", "PLAIN_MESSAGE");

       messagePanel = new ButtonPanel("Message", "String", "Icon", "Component", "Other",

             "Object[]");

       optionTypePanel = new ButtonPanel("Confirm", "DEFAULT_OPTION", "YES_NO_OPTION",

             "YES_NO_CANCEL_OPTION", "OK_CANCEL_OPTION");

       optionsPanel = new ButtonPanel("Option", "String[]", "Icon[]", "Object[]");

       inputPanel = new ButtonPanel("Input", "Text field", "Combo box");

       gridPanel.add(typePanel);

       gridPanel.add(messageTypePanel);

       gridPanel.add(messagePanel);

       gridPanel.add(optionTypePanel);

       gridPanel.add(optionsPanel);

       gridPanel.add(inputPanel);

       // 添加带有显示按钮的面板

       JPanel showPanel = new JPanel();

       JButton showButton = new JButton("Show");

       showButton.addActionListener(new ShowAction());

       showPanel.add(showButton);//把按钮添加到面板上

       add(gridPanel, BorderLayout.CENTER);

       add(showPanel, BorderLayout.SOUTH);

       pack();

    }

    /**

     * Gets the currently selected message.

     * @return a string, icon, component, or object array, depending on the Message panel selection

     */

    public Object getMessage()

    {

       String s = messagePanel.getSelection();

       if (s.equals("String")) return messageString;

       else if (s.equals("Icon")) return messageIcon;

       else if (s.equals("Component")) return messageComponent;

       else if (s.equals("Object[]")) return new Object[] { messageString, messageIcon,

             messageComponent, messageObject };

       else if (s.equals("Other")) return messageObject;

       else return null;

    }

    /**

     * Gets the currently selected options.

     * @return an array of strings, icons, or objects, depending on the Option panel selection

     */

    public Object[] getOptions()

    {

       String s = optionsPanel.getSelection();

       if (s.equals("String[]")) return new String[] { "Yellow", "Blue", "Red" };

       else if (s.equals("Icon[]")) return new Icon[] { new ImageIcon("yellow-ball.gif"),

             new ImageIcon("blue-ball.gif"), new ImageIcon("red-ball.gif") };

       else if (s.equals("Object[]")) return new Object[] { messageString, messageIcon,

             messageComponent, messageObject };

       else return null;

    }

    /**

     * Gets the selected message or option type

     * @param panel the Message Type or Confirm panel

     * @return the selected XXX_MESSAGE or XXX_OPTION constant from the JOptionPane class

     */

    public int getType(ButtonPanel panel)

    {

       String s = panel.getSelection();

       try

       {

          return JOptionPane.class.getField(s).getInt(null);

       }

       catch (Exception e)

       {

          return -;

       }

    }

    /**

     * The action listener for the Show button shows a Confirm, Input, Message, or Option dialog

     * depending on the Type panel selection.

     */

    private class ShowAction implements ActionListener

    {

       public void actionPerformed(ActionEvent event)

       {

          if (typePanel.getSelection().equals("Confirm")) JOptionPane.showConfirmDialog( //显示确认对话框

                OptionDialogFrame.this, getMessage(), "Title", getType(optionTypePanel),

                getType(messageTypePanel));

          else if (typePanel.getSelection().equals("Input"))

          {

             if (inputPanel.getSelection().equals("Text field")) JOptionPane.showInputDialog(//显示输入对话框

                   OptionDialogFrame.this, getMessage(), "Title", getType(messageTypePanel));

             else JOptionPane.showInputDialog(OptionDialogFrame.this, getMessage(), "Title",

                   getType(messageTypePanel), null, new String[] { "Yellow", "Blue", "Red" },

                   "Blue");

          }

          else if (typePanel.getSelection().equals("Message")) JOptionPane.showMessageDialog(//显示信息对话框

                OptionDialogFrame.this, getMessage(), "Title", getType(messageTypePanel));

          else if (typePanel.getSelection().equals("Option")) JOptionPane.showOptionDialog(//显示选择对话框

                OptionDialogFrame.this, getMessage(), "Title", getType(optionTypePanel),

                getType(messageTypePanel), null, getOptions(), getOptions()[]);

       }

    }

 }

 /**

  * A component with a painted surface

  */

 class SampleComponent extends JComponent

 {

    public void paintComponent(Graphics g)

    {

       Graphics2D g2 = (Graphics2D) g;

       Double rect = new Rectangle2D.Double(, , getWidth() - , getHeight() - );

       g2.setPaint(Color.YELLOW);

       g2.fill(rect);

       g2.setPaint(Color.BLUE);

       g2.draw(rect);

    }

    public Dimension getPreferredSize()

    {

       return new Dimension(, );

    }

 }

 import javax.swing.*;

 /**

  * A panel with radio buttons inside a titled border.

  */

 public class ButtonPanel extends JPanel

 {

    private ButtonGroup group;

    /**

     * Constructs a button panel.

     * @param title the title shown in the border

     * @param options an array of radio button labels

     */

    public ButtonPanel(String title, String... options)

    {

       setBorder(BorderFactory.createTitledBorder(BorderFactory.createEtchedBorder(), title));//创建一个带标题的边框

       setLayout(new BoxLayout(this, BoxLayout.Y_AXIS));

       group = new ButtonGroup();

       // 为每个选项制作一个单选按钮

       for (String option : options)

       {

          JRadioButton button = new JRadioButton(option);

          button.setActionCommand(option);

          add(button);

          group.add(button);

          button.setSelected(option == options[]);

       }

    }

    /**

     * Gets the currently selected option.

     * @return the label of the currently selected radio button.

     */

    public String getSelection()

    {

       return group.getSelection().getActionCommand();

    }

 }

 import java.awt.*;

 import javax.swing.*;

 /**

  * @version 1.35 2018-04-10

  * @author Cay Horstmann

  */

 public class OptionDialogTest

 {

    public static void main(String[] args)

    {

       EventQueue.invokeLater(() -> {

          OptionDialogFrame frame = new OptionDialogFrame();

          frame.setTitle("OptionDialogTest");

          frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);

          frame.setVisible(true);

       });

    }

 }

 import javax.swing.JFrame;

 import javax.swing.JMenu;

 import javax.swing.JMenuBar;

 import javax.swing.JMenuItem;

 /**

  * A frame with a menu whose File->About action shows a dialog.

  */

 public class DialogFrame extends JFrame

 {

    private static final int DEFAULT_WIDTH = ;

    private static final int DEFAULT_HEIGHT = ;

    private AboutDialog dialog;

    public DialogFrame()

    {

       setSize(DEFAULT_WIDTH, DEFAULT_HEIGHT);

       // 构造文件菜单

       JMenuBar menuBar = new JMenuBar();//创建一个菜单栏

       setJMenuBar(menuBar);

       JMenu fileMenu = new JMenu("File");

       menuBar.add(fileMenu);//将File菜单添加到菜单栏上

       // 添加和退出菜单项

       // About项目显示About对话框

       JMenuItem aboutItem = new JMenuItem("About");

       aboutItem.addActionListener(event -> {

          if (dialog == null) // first time

             dialog = new AboutDialog(DialogFrame.this);

          dialog.setVisible(true); // 弹出对话框

       });

       fileMenu.add(aboutItem);

       // 退出项目退出程序

       JMenuItem exitItem = new JMenuItem("Exit");

       exitItem.addActionListener(event -> System.exit());

       fileMenu.add(exitItem);//将菜单项添加到菜单上

    }

 }

 import java.awt.*;

 import javax.swing.*;

 /**

  * @version 1.35 2018-04-10

  * @author Cay Horstmann

  */

 public class DialogTest

 {

    public static void main(String[] args)

    {

       EventQueue.invokeLater(() -> {

          DialogFrame frame = new DialogFrame();

          frame.setTitle("DialogTest");

          frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);

          frame.setVisible(true);

       });

    }

 }

 import java.awt.BorderLayout;

 import javax.swing.JButton;

 import javax.swing.JDialog;

 import javax.swing.JFrame;

 import javax.swing.JLabel;

 import javax.swing.JPanel;

 /**

  * A sample modal dialog that displays a message and waits for the user to click

  * the OK button.

  */

 public class AboutDialog extends JDialog

 {

    public AboutDialog(JFrame owner)

    {

       super(owner, "About DialogTest", true);

       //将html标签添加到中心

       add(

          new JLabel(

             "<html><h1><i>Core Java</i></h1><hr>By Cay Horstmann</html>"),

          BorderLayout.CENTER);

       // ok按钮关闭对话框

       JButton ok = new JButton("OK");

       ok.addActionListener(event -> setVisible(false));

       // 将“ok”按钮添加到南部边框

       JPanel panel = new JPanel();

       panel.add(ok);

       add(panel, BorderLayout.SOUTH);

       pack();

    }

 }

 import java.awt.*;

 import java.awt.event.*;

 import javax.swing.*;

 /**

  * A frame with a menu whose File->Connect action shows a password dialog.

  */

 public class DataExchangeFrame extends JFrame

 {

    public static final int TEXT_ROWS = ;

    public static final int TEXT_COLUMNS = ;

    private PasswordChooser dialog = null;

    private JTextArea textArea;

    public DataExchangeFrame()

    {

       // 构建文件菜单

       JMenuBar mbar = new JMenuBar();//创建一个菜单栏

       setJMenuBar(mbar);

       JMenu fileMenu = new JMenu("File");  //创建一个菜单

       mbar.add(fileMenu);//在菜单栏中添加菜单

       // 添加连接和退出菜单项

       JMenuItem connectItem = new JMenuItem("Connect");//创建一个菜单项

       connectItem.addActionListener(new ConnectAction());

       fileMenu.add(connectItem);//将菜单项添加到菜单

       // Exit项目退出程序

       JMenuItem exitItem = new JMenuItem("Exit");

       exitItem.addActionListener(event -> System.exit());

       fileMenu.add(exitItem);

       textArea = new JTextArea(TEXT_ROWS, TEXT_COLUMNS);

       add(new JScrollPane(textArea), BorderLayout.CENTER);//为文本区添加滚动条并放在边框的中间

       pack();

    }

    /**

     * The Connect action pops up the password dialog.

     */

    private class ConnectAction implements ActionListener

    {

       public void actionPerformed(ActionEvent event)

       {

          // 如果第一次构建对话框

          if (dialog == null) dialog = new PasswordChooser();

          // 设置默认值

          dialog.setUser(new User("yourname", null));

          // 弹出对话框

          if (dialog.showDialog(DataExchangeFrame.this, "Connect"))

          {

             // 如果接受，检索用户输入

             User u = dialog.getUser();

             textArea.append("user name = " + u.getName() + ", password = "

                + (new String(u.getPassword())) + "\n");

          }

       }

    }

 }

 import java.awt.*;

 import javax.swing.*;

 /**

  * @version 1.35 2018-04-10

  * @author Cay Horstmann

  */

 public class DataExchangeTest

 {

    public static void main(String[] args)

    {

       EventQueue.invokeLater(() -> {

          DataExchangeFrame frame = new DataExchangeFrame();

          frame.setTitle("DataExchangeTest");

          frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);

          frame.setVisible(true);

       });

    }

 }

 import java.awt.BorderLayout;

 import java.awt.Component;

 import java.awt.Frame;

 import java.awt.GridLayout;

 import javax.swing.JButton;

 import javax.swing.JDialog;

 import javax.swing.JLabel;

 import javax.swing.JPanel;

 import javax.swing.JPasswordField;

 import javax.swing.JTextField;

 import javax.swing.SwingUtilities;

 /**

  * A password chooser that is shown inside a dialog.

  */

 public class PasswordChooser extends JPanel

 {

    private JTextField username;

    private JPasswordField password;

    private JButton okButton;

    private boolean ok;

    private JDialog dialog;

    public PasswordChooser()

    {

       setLayout(new BorderLayout());

       // 构建一个包含用户名和密码字段的面板

       JPanel panel = new JPanel();

       panel.setLayout(new GridLayout(, ));//设置面板的布局管理器为2*2的网格

       panel.add(new JLabel("User name:"));

       panel.add(username = new JTextField(""));//给面板添加文本域

       panel.add(new JLabel("Password:"));

       panel.add(password = new JPasswordField(""));

       add(panel, BorderLayout.CENTER);//将该面板添加到边框的中间

       // 创建终止对话框的“确定”和“取消”按钮

       okButton = new JButton("Ok");

       okButton.addActionListener(event -> {

          ok = true;

          dialog.setVisible(false);

       });

       JButton cancelButton = new JButton("Cancel");

       cancelButton.addActionListener(event -> dialog.setVisible(false));

       // 向南部边框添加按钮

       JPanel buttonPanel = new JPanel();

       buttonPanel.add(okButton);

       buttonPanel.add(cancelButton);

       add(buttonPanel, BorderLayout.SOUTH);

    }

    /**

     * Sets the dialog defaults.

     * @param u the default user information

     */

    public void setUser(User u)

    {

       username.setText(u.getName());

    }

    /**

     * Gets the dialog entries.

     * @return a User object whose state represents the dialog entries

     */

    public User getUser()

    {

       return new User(username.getText(), password.getPassword());

    }

    /**

     * Show the chooser panel in a dialog.

     * @param parent a component in the owner frame or null

     * @param title the dialog window title

     */

    public boolean showDialog(Component parent, String title)

    {

       ok = false;

       // 定位到owner 框架

       Frame owner = null;

       if (parent instanceof Frame)

          owner = (Frame) parent;

       else

          owner = (Frame) SwingUtilities.getAncestorOfClass(Frame.class, parent);

       //如果是第一次，或者owner已经更改，请创建新对话框

       if (dialog == null || dialog.getOwner() != owner)

       {

          dialog = new JDialog(owner, true);

          dialog.add(this);

          dialog.getRootPane().setDefaultButton(okButton);

          dialog.pack();

       }

       // 设置标题和显示对话框

       dialog.setTitle(title);

       dialog.setVisible(true);

       return ok;

    }

 }

 /**

  * A user has a name and password. For security reasons, the password is stored as a char[], not a

  * String.

  */

 public class User

 {

    private String name;

    private char[] password;

    public User(String aName, char[] aPassword)

    {

       name = aName;

       password = aPassword;

    }

    public String getName()

    {

       return name;

    }

    public char[] getPassword()

    {

       return password;

    }

    public void setName(String aName)

    {

       name = aName;

    }

    public void setPassword(char[] aPassword)

    {

       password = aPassword;

    }

 }

 import java.io.*;

 import javax.swing.*;

 import javax.swing.filechooser.*;

 import javax.swing.filechooser.FileFilter;

 /**

  * A frame that has a menu for loading an image and a display area for the

  * loaded image.

  */

 public class ImageViewerFrame extends JFrame

 {

    private static final int DEFAULT_WIDTH = ;

    private static final int DEFAULT_HEIGHT = ;

    private JLabel label;

    private JFileChooser chooser;

    public ImageViewerFrame()

    {

       setSize(DEFAULT_WIDTH, DEFAULT_HEIGHT);

       // 设置菜单栏

       JMenuBar menuBar = new JMenuBar();

       setJMenuBar(menuBar);

       JMenu menu = new JMenu("File");

       menuBar.add(menu);

       JMenuItem openItem = new JMenuItem("Open");

       menu.add(openItem);

       openItem.addActionListener(event -> {

          chooser.setCurrentDirectory(new File("."));

          // 显示文件选择器对话框

             int result = chooser.showOpenDialog(ImageViewerFrame.this);

             // 如果图像文件被接受，将其设置为标签的图标

             if (result == JFileChooser.APPROVE_OPTION)

             {

                String name = chooser.getSelectedFile().getPath();

                label.setIcon(new ImageIcon(name));

                pack();

             }

          });

       JMenuItem exitItem = new JMenuItem("Exit");

       menu.add(exitItem);

       exitItem.addActionListener(event -> System.exit());

       // 使用标签显示图像

       label = new JLabel();

       add(label);

       // 设置文件选择器

       chooser = new JFileChooser();

       // 接受所有以jpg,jpeg ,gif结尾的图像文件

       FileNameExtensionFilter filter = new FileNameExtensionFilter(

             "Image files", "jpg", "jpeg", "gif");

       chooser.setFileFilter(filter);

       chooser.setAccessory(new ImagePreviewer(chooser));

       chooser.setFileView(new FileIconView(filter, new ImageIcon("palette.gif")));

    }

 }

 import java.awt.*;

 import java.io.*;

 import javax.swing.*;

 /**

  * A file chooser accessory that previews images.

  */

 public class ImagePreviewer extends JLabel

 {

    /**

     * Constructs an ImagePreviewer.

     * @param chooser the file chooser whose property changes trigger an image

     *        change in this previewer

     */

    public ImagePreviewer(JFileChooser chooser)

    {

       setPreferredSize(new Dimension(, ));

       setBorder(BorderFactory.createEtchedBorder());

       chooser.addPropertyChangeListener(event -> {

          if (event.getPropertyName() == JFileChooser.SELECTED_FILE_CHANGED_PROPERTY)

          {

             // 用户选择了一个新文件

             File f = (File) event.getNewValue();

             if (f == null)

             {

                setIcon(null);

                return;

             }

             // 将图像读入图标

             ImageIcon icon = new ImageIcon(f.getPath());

             // 如果图标太大，缩放它

             if (icon.getIconWidth() > getWidth())

                icon = new ImageIcon(icon.getImage().getScaledInstance(

                      getWidth(), -, Image.SCALE_DEFAULT));

             setIcon(icon);

          }

       });

    }

 }

 import java.io.*;

 import javax.swing.*;

 import javax.swing.filechooser.*;

 import javax.swing.filechooser.FileFilter;

 /**

  *显示与文件过滤器匹配的所有文件的图标的文件视图。

  */

 public class FileIconView extends FileView

 {

    private FileFilter filter;

    private Icon icon;

    /**

     * Constructs a FileIconView.

     * @param aFilter a file filter--all files that this filter accepts will be shown

     * with the icon.

     * @param anIcon--the icon shown with all accepted files.

     */

    public FileIconView(FileFilter aFilter, Icon anIcon)

    {

       filter = aFilter;

       icon = anIcon;

    }

    public Icon getIcon(File f)

    {

       if (!f.isDirectory() && filter.accept(f)) return icon;

       else return null;

    }

 }

 import java.awt.*;

 import javax.swing.*;

 /**

  * @version 1.26 2018-04-10

  * @author Cay Horstmann

  */

 public class FileChooserTest

 {

    public static void main(String[] args)

    {

       EventQueue.invokeLater(() -> {

          ImageViewerFrame frame = new ImageViewerFrame();

          frame.setTitle("FileChooserTest");

          frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);

          frame.setVisible(true);

       });

    }

 }

 package 第十五周;

 import javax.swing.*;

 /**

  * A frame with a color chooser panel

  */

 public class ColorChooserFrame extends JFrame

 {

    private static final int DEFAULT_WIDTH = ;    //两个私有属性，常量

    private static final int DEFAULT_HEIGHT = ;

    public ColorChooserFrame()    //ColorChooserFrame构造器

    {

       setSize(DEFAULT_WIDTH, DEFAULT_HEIGHT); //设置为两个常量大小的框架

       // add color chooser panel to frame

       ColorChooserPanel panel = new ColorChooserPanel();  //创建一个ColorChooserPanel类对象panel

       add(panel); //将panel添加到框架里面

    }

 }

 package 第十五周;

 import java.awt.Color;

 import java.awt.Frame;

 import java.awt.event.ActionEvent;

 import java.awt.event.ActionListener;

 import javax.swing.JButton;

 import javax.swing.JColorChooser;

 import javax.swing.JDialog;

 import javax.swing.JPanel;

 /**

  * A panel with buttons to pop up three types of color choosers

  */

 public class ColorChooserPanel extends JPanel

 {

    public ColorChooserPanel()      //ColorChooserPanel构造器

    {

       JButton modalButton = new JButton("Modal");     //创建一个JButton按钮对象

       modalButton.addActionListener(new ModalListener());    //动作监听器对象

       add(modalButton);    //将JButton对象添加到框架里面

       JButton modelessButton = new JButton("Modeless");     //新建一个Modeless按钮

       modelessButton.addActionListener(new ModelessListener());   //添加动作监听器

       add(modelessButton);   //将按钮添加到框架当中

       JButton immediateButton = new JButton("Immediate");  //新建一个Immediate按钮

       immediateButton.addActionListener(new ImmediateListener());  //添加动作监听器

       add(immediateButton);  //将immediateButton添加到框架当中

    }

    /**

     * This listener pops up a modal color chooser

     */

    private class ModalListener implements ActionListener   //创建一个实现ActionListener接口的类ModalListener

    {

       public void actionPerformed(ActionEvent event)    //actionPerformed方法

       {

          Color defaultColor = getBackground();    //创建一个颜色类对象，设置为背景颜色

          Color selected = JColorChooser.showDialog(ColorChooserPanel.this, "Set background",

                defaultColor);

          if (selected != null) setBackground(selected);

       }

    }

    /**

     * This listener pops up a modeless color chooser. The panel color is changed when the user

     * clicks the OK button.

     */

    private class ModelessListener implements ActionListener  //ModelessListener类实现了ActionListener接口

    {

       private JDialog dialog;    //对话框

       private JColorChooser chooser;     //颜色选择器

       public ModelessListener()      //ModelessListener构造器

       {

          chooser = new JColorChooser();   //创建一个JColorChooser选择器类对象

          dialog = JColorChooser.createDialog(ColorChooserPanel.this, "Background Color",

                false /* not modal */, chooser,

                event -> setBackground(chooser.getColor()),

                null /* no Cancel button listener */);

       }//创建一个对话框，颜色选择器面板ColorChooserPanel.this是本类，提供组件。设置背景颜色为颜色选择器调用getColor方法得到的颜色

       public void actionPerformed(ActionEvent event)  //actionPerformed方法

       {

          chooser.setColor(getBackground());   //设置背景颜色

          dialog.setVisible(true);    //设置对话框组件可见

       }

    }

    /**

     * This listener pops up a modeless color chooser. The panel color is changed immediately when

     * the user picks a new color.

     */

    private class ImmediateListener implements ActionListener    //ImmediateListener是实现ActionListener接口的类

    {

       private JDialog dialog;

       private JColorChooser chooser;   //私有属性，颜色选择器的定义

       public ImmediateListener()   //ImmediateListener构造器

       {

          chooser = new JColorChooser();    //新建一个颜色选择器类对象

          chooser.getSelectionModel().addChangeListener(

                event -> setBackground(chooser.getColor()));

          dialog = new JDialog((Frame) null, false /* not modal */);

          dialog.add(chooser);//添加chooser到文本框当中

          dialog.pack();   //获取对话框的首选大小

       }

       public void actionPerformed(ActionEvent event)//actionPerformed方法

       {

          chooser.setColor(getBackground());    //设置背景颜色

          dialog.setVisible(true);   //设置组件可见

       }

    }

 }

 package 第十五周;

 import java.awt.*;

 import javax.swing.*;

 /**

  * @version 1.04 2015-06-12

  * @author Cay Horstmann

  */

 public class ColorChooserTest          //框架整体框架

 {

    public static void main(String[] args)

    {

       EventQueue.invokeLater(() -> {

          JFrame frame = new ColorChooserFrame();

          frame.setTitle("ColorChooserTest");

          frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);

          frame.setVisible(true);

       });

    }

 }