The JOptionPane Message Argument is an Object, not a String. : JOptionPane Dialog « Swing « Java Tutorial

1. Java Tutorial
2. Swing
3. JOptionPane Dialog

1. If the message is an array of objects (Object[ ]), make the JOptionPane place each entry onto a separate row.
2. If the message is a Component, place the component in the message area.
3. If the message is an Icon, place the Icon within a JLabel and display the label in the message area.
4. If the message is an Object, convert it to a String with toString(), place the String in a JLabel, and display the label in the message area.

import java.awt.event.WindowAdapter;
import java.awt.event.WindowEvent;

import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JOptionPane;

public class Test2 extends JFrame {
  public Test2() {
    setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);

    getContentPane().add(new JLabel("Placeholder label"));
    pack();
    setSize(200, 200);
    setVisible(true);

    Object msg[] = { "Complex Message", new JButton("A component"),
        new Object[] { "  Nested", "  Array" }, "for JOptionPane" };
    Object type[] = { "Animal", "Vegetable", "Mineral" };
    int result = JOptionPane.showOptionDialog(this, msg, "Choose",
        JOptionPane.YES_NO_OPTION, JOptionPane.QUESTION_MESSAGE, null, type,
        null);

    System.out.println("Result (index)= " + result + " (" + type[result] + ")");
  }

  public static void main(String[] args) {
    new Test2();
  }
}

14.56.JOptionPane Dialog
	14.56.1.	Creating a JOptionPane
	14.56.2.	The JOptionPane Message Argument is an Object, not a String.
	14.56.3.	The JOptionPane Message Type and Icon Arguments
	14.56.4.	The JOptionPane Option Type Argument
	14.56.5.	The JOptionPane Options and Initial Value Arguments
	14.56.6.	JOptionPane Option Position Constants
	14.56.7.	Using JOptionPane to Display a Message
	14.56.8.	Using JOptionPane to Prompt User Confirmation
	14.56.9.	Using JOptionPane to prompt user confirmation: a demo
	14.56.10.	Using JOptionPane to Obtain User Input
	14.56.11.	Using JOptionPane with a predefined selections
	14.56.12.	Display JOptionPane
	14.56.13.	JOptionPane Utility Class: Get selection from JOptionPane
	14.56.14.	Message Pop-Ups
	14.56.15.	Confirm Pop-Ups
	14.56.16.	Input Pop-Ups
	14.56.17.	Big value list for JOptionInput Dialog
	14.56.18.	Option Pop-Ups
	14.56.19.	String Array Option Popups
	14.56.20.	Complex message arguments
	14.56.21.	Adding Components to the Button Area: Using JOptionPane with a JButton containing a text label and an icon
	14.56.22.	Sample JOptionPane in a JDialog
	14.56.23.	Instant Input Dialogs
	14.56.24.	JOptionPane WARNING_MESSAGE
	14.56.25.	Dialog without parent component
	14.56.26.	To displays a dialog with a list of choices in a drop-down list box
	14.56.27.	Understanding the Message Property
	14.56.28.	Using JOptionPane with a JSlider
	14.56.29.	Displaying Multiline Messages
	14.56.30.	Setting JOptionPane button labels to French
	14.56.31.	Tip Of Day Dialog
	14.56.32.	About dialog
	14.56.33.	Create a Confirm Dialog Box
	14.56.34.	Create a Message Dialog Box
	14.56.35.	Yes no cancel dialog
	14.56.36.	OK cancel option dialog
	14.56.37.	Dialog with default options
	14.56.38.	Customize JOptionPane buttons
	14.56.39.	Modal dialog with yes/no button
	14.56.40.	Modal dialog with OK/cancel and a text field
	14.56.41.	Wait for a click and then quit
	14.56.42.	Localize a JOptionPane dialog
	14.56.43.	Modifiable JOptionPane
	14.56.44.	Customizing a JOptionPane Look and Feel