A frame with a menu whose File->Connect action shows a password dialog
/*
This program is a part of the companion code for Core Java 8th ed.
(http://horstmann.com/corejava)
This program is free software: you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation, either version 3 of the License, or
(at your option) any later version.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
import java.awt.BorderLayout;
import java.awt.Component;
import java.awt.EventQueue;
import java.awt.Frame;
import java.awt.GridLayout;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import javax.swing.JButton;
import javax.swing.JDialog;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JMenu;
import javax.swing.JMenuBar;
import javax.swing.JMenuItem;
import javax.swing.JPanel;
import javax.swing.JPasswordField;
import javax.swing.JScrollPane;
import javax.swing.JTextArea;
import javax.swing.JTextField;
import javax.swing.SwingUtilities;
/**
* @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;
}
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