变更5

DataExchangeTest.java

@@ -0,0 +1,236 @@
+import java.awt.*;
+import java.awt.event.*;
+import javax.swing.*;
+
+/**
+ * @version 1.33 2007-06-12
+ * @author Cay Horstmann
+ */
+public class DataExchangeTest
+{
+   public static void main(String[] args)
+   {
+      EventQueue.invokeLater(new Runnable()
+         {
+            public void run()
+            {
+               DataExchangeFrame frame = new DataExchangeFrame();
+               frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
+               frame.setVisible(true);
+            }
+         });
+   }
+}
+
+/**
+ * A frame with a menu whose File->Connect action shows a password dialog.
+ */
+class DataExchangeFrame extends JFrame
+{
+   public DataExchangeFrame()
+   {
+      setTitle("DataExchangeTest");
+      setSize(DEFAULT_WIDTH, DEFAULT_HEIGHT);
+
+      // construct a File menu
+
+      JMenuBar mbar = new JMenuBar();
+      setJMenuBar(mbar);
+      JMenu fileMenu = new JMenu("File");
+      mbar.add(fileMenu);
+
+      // add Connect and Exit menu items
+
+      JMenuItem connectItem = new JMenuItem("Connect");
+      connectItem.addActionListener(new ConnectAction());
+      fileMenu.add(connectItem);
+
+      // The Exit item exits the program
+
+      JMenuItem exitItem = new JMenuItem("Exit");
+      exitItem.addActionListener(new ActionListener()
+         {
+            public void actionPerformed(ActionEvent event)
+            {
+               System.exit(0);
+            }
+         });
+      fileMenu.add(exitItem);
+
+      textArea = new JTextArea();
+      add(new JScrollPane(textArea), BorderLayout.CENTER);
+   }
+
+   public static final int DEFAULT_WIDTH = 300;
+   public static final int DEFAULT_HEIGHT = 200;
+
+   private PasswordChooser dialog = null;
+   private JTextArea textArea;
+
+   /**
+    * The Connect action pops up the password dialog.
+    */
+
+   private class ConnectAction implements ActionListener
+   {
+      public void actionPerformed(ActionEvent event)
+      {
+         // if first time, construct dialog
+
+         if (dialog == null) dialog = new PasswordChooser();
+
+         // set default values
+         dialog.setUser(new User("yourname", null));
+
+         // pop up dialog
+         if (dialog.showDialog(DataExchangeFrame.this, "Connect"))
+         {
+            // if accepted, retrieve user input
+            User u = dialog.getUser();
+            textArea.append("user name = " + u.getName() + ", password = "
+                  + (new String(u.getPassword())) + "\n");
+         }
+      }
+   }
+}
+
+/**
+ * A password chooser that is shown inside a dialog
+ */
+class PasswordChooser extends JPanel
+{
+   public PasswordChooser()
+   {
+      setLayout(new BorderLayout());
+
+      // construct a panel with user name and password fields
+
+      JPanel panel = new JPanel();
+      panel.setLayout(new GridLayout(2, 2));
+      panel.add(new JLabel("User name:"));
+      panel.add(username = new JTextField(""));
+      panel.add(new JLabel("Password:"));
+      panel.add(password = new JPasswordField(""));
+      add(panel, BorderLayout.CENTER);
+
+      // create Ok and Cancel buttons that terminate the dialog
+
+      okButton = new JButton("Ok");
+      okButton.addActionListener(new ActionListener()
+         {
+            public void actionPerformed(ActionEvent event)
+            {
+               ok = true;
+               dialog.setVisible(false);
+            }
+         });
+
+      JButton cancelButton = new JButton("Cancel");
+      cancelButton.addActionListener(new ActionListener()
+         {
+            public void actionPerformed(ActionEvent event)
+            {
+               dialog.setVisible(false);
+            }
+         });
+
+      // add buttons to southern border
+
+      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;
+
+      // locate the owner frame
+
+      Frame owner = null;
+      if (parent instanceof Frame) owner = (Frame) parent;
+      else owner = (Frame) SwingUtilities.getAncestorOfClass(Frame.class, parent);
+
+      // if first time, or if owner has changed, make new dialog
+
+      if (dialog == null || dialog.getOwner() != owner)
+      {
+         dialog = new JDialog(owner, true);
+         dialog.add(this);
+         dialog.getRootPane().setDefaultButton(okButton);
+         dialog.pack();
+      }
+
+      // set title and show dialog
+
+      dialog.setTitle(title);
+      dialog.setVisible(true);
+      return ok;
+   }
+
+   private JTextField username;
+   private JPasswordField password;
+   private JButton okButton;
+   private boolean ok;
+   private JDialog dialog;
+}
+
+/**
+ * A user has a name and password. For security reasons, the password is stored as a char[], not a
+ * String.
+ */
+class User
+{
+   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;
+   }
+
+   private String name;
+   private char[] password;
+}