Speed up your Swing GUI construction with better building blocks

public class CustomerDialog extends StandardDialog
{
    private JTextField myCustomerCodeField = new JTextField();
    private JTextField myNameField = new JTextField();
    private JTextArea myAddressField = new JTextArea(3, 20);
    ...

    private LabelledItemPanel myContentPane = new LabelledItemPanel();

    public CustomerDialog()
    {
        init();
    }

    private void init()
    {
        setTitle("Customer Dialog");

        myContentPane.setBorder(BorderFactory.createEtchedBorder());

        myContentPane.addItem("Customer Code", myCustomerCodeField);
        myContentPane.addItem("Name", myNameField);
        myContentPane.addItem("Address", new JScrollPane(myAddressField,
            JScrollPane.VERTICAL_SCROLLBAR_ALWAYS,
            JScrollPane.HORIZONTAL_SCROLLBAR_NEVER));
        ...

        setContentPane(myContentPane);
    }

    public CustomerData getCustomerData()
    {
        CustomerData customerData = new CustomerData();

        customerData.myCustomerCode = myCustomerCodeField.getText();
        customerData.myName = myNameField.getText();
        customerData.myAddress = myAddressField.getText();
        ...

        return customerData;
    }
}

// A method in some class using the CustomerDialog
{
    CustomerDialog dialog = new CustomerDialog();

    dialog.pack();

    dialog.show();

    if(!dialog.hasUserCancelled())
    {
        CustomerData customerData = dialog.getCustomerData();

        // Process the data
    }
}

protected boolean isValidData()
{
    if(myCustomerCodeField.getText().equals(""))
    {
        JOptionPane.showMessageDialog(this,
            "Please enter a Customer Code",
            "Blank Customer Code",
            JOptionPane.WARNING_MESSAGE);

        myCustomerCodeField.requestFocus();

        return false;
    }

    if(myNameField.getText().equals(""))
    {
        JOptionPane.showMessageDialog(this,
            "Please enter a Name",
            "Blank Name",
            JOptionPane.WARNING_MESSAGE);

        myNameField.requestFocus();

        return false;
    }

    return true;
}

    private void init()
    {
        setModal(true);
        setDefaultCloseOperation(DO_NOTHING_ON_CLOSE);

        // Setup the internal content pane to hold the user content pane
        // and the standard button panel

        JPanel internalContentPane = new JPanel();

        internalContentPane.setLayout(
            new BorderLayout(COMPONENT_SPACING, COMPONENT_SPACING));

        internalContentPane.setBorder(
            BorderFactory.createEmptyBorder(COMPONENT_SPACING,
                COMPONENT_SPACING, COMPONENT_SPACING, COMPONENT_SPACING));

        // Create the standard button panel with "Ok" and "Cancel"

        Action okAction = new AbstractAction("Ok")
        {
            public void actionPerformed(ActionEvent actionEvent)
            {
                if(isValidData())
                {
                    myIsDialogCancelled = false;

                    dispose();
                }
            }
        };

        Action cancelAction = new AbstractAction("Cancel")
        {
            public void actionPerformed(ActionEvent actionEvent)
            {
                myIsDialogCancelled = true;

                dispose();
            }
        };

        JPanel buttonPanel = new JPanel();

        buttonPanel.setBorder(BorderFactory.createEmptyBorder(0, 0, 0, 0));

        buttonPanel.add(new JButton(okAction));
        buttonPanel.add(new JButton(cancelAction));

        internalContentPane.add(buttonPanel, BorderLayout.SOUTH);

        // Initialise the user content pane with a JPanel

        setContentPane(new JPanel(new BorderLayout()));

        super.setContentPane(internalContentPane);

        // Finally, add a listener for the window close button.
        // Process this event the same as the "Cancel" button.

        WindowAdapter windowAdapter = new WindowAdapter()
        {
            public void windowClosing(WindowEvent windowEvent)
            {
                myIsDialogCancelled = true;

                dispose();
            }
        };

        addWindowListener(windowAdapter);
    }