Java: Custom Buttons in showInputDialog

You can use custom component instead of a string message, for example:

import javax.swing.JLabel;
import javax.swing.JOptionPane;
import javax.swing.JPanel;
import javax.swing.JTextField;

public class TestDialog {

    public static void main(String[] args) {
        Object[] options1 = { "Try This Number", "Choose A Random Number",
                "Quit" };

        JPanel panel = new JPanel();
        panel.add(new JLabel("Enter number between 0 and 1000"));
        JTextField textField = new JTextField(10);
        panel.add(textField);

        int result = JOptionPane.showOptionDialog(null, panel, "Enter a Number",
                JOptionPane.YES_NO_CANCEL_OPTION, JOptionPane.PLAIN_MESSAGE,
                null, options1, null);
        if (result == JOptionPane.YES_OPTION){
            JOptionPane.showMessageDialog(null, textField.getText());
        }
    }
}

Have a look at How to Make Dialogs: Customizing Button Text.

Here is an example given:

Object[] options = {"Yes, please",
                    "No, thanks",
                    "No eggs, no ham!"};
int n = JOptionPane.showOptionDialog(frame,//parent container of JOptionPane
    "Would you like some green eggs to go "
    + "with that ham?",
    "A Silly Question",
    JOptionPane.YES_NO_CANCEL_OPTION,
    JOptionPane.QUESTION_MESSAGE,
    null,//do not use a custom Icon
    options,//the titles of buttons
    options[2]);//default button title