JDialog does not display proper text

Question

I'm creating an About dialog for my program and have run into an issue. Whenever I launch the dialog, the title text sets properly, but the text inside the dialog says "JOptionPane Message". Before it wouldn't even show the label I added to the dialog, but that fixed itself (I'm not entirely sure how) but now it displays both the added text and the "JOptionPane Message".

Code for the dialog:

    about.addActionListener(new ActionListener() {
        public void actionPerformed(ActionEvent ae) {
            JOptionPane optionPane = new JOptionPane();
            JDialog dialog = optionPane.createDialog("About");
            JLabel aboutText = new JLabel("Text goes here", JLabel.CENTER);
            dialog.add(aboutText, BorderLayout.NORTH);
            dialog.setVisible(true);
        }
    });

So the text works now, which is nice. But how do I get rid of the part that says "JOptionPane Message"?

Answer 1

Here's what you do to procure the about dialog. Plus, it's only one line of code!

JOptionPane.showMessageDialog(this, "Text goes here", "About", JOptionPane.INFORMATION_MESSAGE);

I assume that this code is inside a subclass of JFrame. If not, replace this with any component inside the window where you want to dialog to appear, or just null for the center of the screen.

You may also want to change "Text goes here" to your own custom message text.

To change the type of message, change JOptionPane.INFORMATION_MESSAGE to one of the following:

• JOptionPane.ERROR_MESSAGE
• JOptionPane.WARNING_MESSAGE
• JOptionPane.QUESTION_MESSAGE
• JOptionPane.PLAIN_MESSAGE

Answer 2

I think people forget just how powerful JOptionPane can be...

If you supply a String as the message Object, JOptionPane will create a JLabel to display it with, if you supply some kind of Component, JOptionPane will simply use it instead, for example...

JLabel label = new JLabel("Bring it on");
label.setIcon(new ImageIcon("logo.png"));
label.setHorizontalAlignment(JLabel.CENTER);
label.setVerticalTextPosition(JLabel.BOTTOM);
label.setHorizontalTextPosition(JLabel.CENTER);
JOptionPane.showMessageDialog(null, label, "About", JOptionPane.PLAIN_MESSAGE);

Answer 3

This occurs because you are using the default constructor new JOptionPane(). From the docs:

Creates a JOptionPane with a test message.

This test message is "JOptionPane Message"

If you use the constructor new JOptionPane("A Message") then the message will become "A Message" where this constructor is taking an Object so using a Label your code would become

JLabel aboutText = new JLabel("Text goes here", JLabel.CENTER);
JOptionPane o = new JOptionPane(aboutText);
JDialog dialog = optionPane.createDialog("About");
dialog.setVisible(true);

You can also use the constructor new JOptionPane(null) to have no object or default message so you can add them later if you like.