[hardwired]

Code:

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

public class DialogExample implements ActionListener {
    JDialog dialog;
    JTextField textField;

    public void actionPerformed(ActionEvent e) {
        String ac = e.getActionCommand();
        if(ac.equals("CANCEL"))
            System.exit(0);
        if(ac.equals("CLEAR"))
            textField.setText("");
        if(ac.equals("OK")) {
            String text = textField.getText();
            if(!text.equals("")) {
                dialog.dispose();
                JOptionPane.showMessageDialog(null, "start your main app");
                // For now we need this line.
                System.exit(0);
            }
        }
    }

    private JPanel getContent() {
        textField = new JTextField(16);
        String[] ids = { "Cancel", "Clear", "OK" };
        JPanel panel = new JPanel(new GridBagLayout());
        GridBagConstraints gbc = new GridBagConstraints();
        gbc.insets = new Insets(2,2,2,2);
        gbc.weightx = 1.0;
        gbc.weighty = 1.0;
        gbc.gridwidth = 3;
        panel.add(textField, gbc);
        gbc.gridy = 1;
        gbc.gridwidth = 1;
        for(int j = 0; j < ids.length; j++) {
            JButton button = new JButton(ids[j]);
            button.setActionCommand(ids[j].toUpperCase());
            button.addActionListener(this);
            panel.add(button, gbc);
        }
        return panel;
    }

    private void launchDialog() {
        dialog = new JDialog(new Frame(), "dialog", false);
        dialog.addWindowListener(closer);
        dialog.getContentPane().add(getContent());
        dialog.setSize(300,200);
        dialog.setLocation(200,200);
        dialog.setVisible(true);
    }

    public static void main(String[] args) {
        DialogExample example = new DialogExample();
        example.launchDialog();
    }

    private WindowListener closer = new WindowAdapter() {
        public void windowClosing(WindowEvent e) {
            System.exit(0);
        }
    };
}