import javax.mail.*;
import javax.swing.*;
import java.awt.*;
import java.awt.event.*;


public class MailAuthenticator extends Authenticator {

  private JDialog passwordDialog = new JDialog(new JFrame(), true);  
  private JLabel mainLabel = new JLabel(
   "Please enter your user name and password: ");
  private JLabel userLabel = new JLabel("User name: ");
  private JLabel passwordLabel = new JLabel("Password: ");
  private JTextField usernameField = new JTextField(20);
  private JPasswordField passwordField = new JPasswordField(20);
  private JButton okButton = new JButton("OK");
  
  public MailAuthenticator() {
    this("");
  }
    
  public MailAuthenticator(String username) {
    
    Container pane = passwordDialog.getContentPane();
    pane.setLayout(new GridLayout(4, 1));
    pane.add(mainLabel);
    JPanel p2 = new JPanel();
    p2.add(userLabel);
    p2.add(usernameField);
    usernameField.setText(username);
    pane.add(p2);
    JPanel p3 = new JPanel();
    p3.add(passwordLabel);
    p3.add(passwordField);
    pane.add(p3);
    JPanel p4 = new JPanel();
    p4.add(okButton);
    pane.add(p4);   
    passwordDialog.pack();
    
    ActionListener al = new HideDialog();
    okButton.addActionListener(al);
    usernameField.addActionListener(al);
    passwordField.addActionListener(al);
    
  }
  
  class HideDialog implements ActionListener {
  
    public void actionPerformed(ActionEvent e) {
      passwordDialog.hide();
    } 
    
  }

  public PasswordAuthentication getPasswordAuthentication() {
    
    passwordDialog.show();
    
    // getPassword() returns an array of chars for security reasons.
    // We need to convert that to a String for 
    // the PasswordAuthentication() constructor.
    String password = new String(passwordField.getPassword());
    String username = usernameField.getText();
    // Erase the password in case this is used again.
    // The provider should cache the password if necessary.
    passwordField.setText("");
    return new PasswordAuthentication(username, password);
    
  }

}