How to open warning/information/error dialog in Swing?

Question

How to open warning/information/error dialog in Swing?

I need standard error dialog with "Ok" button and "red cross" image. I.e. analog of org.eclipse.jface.dialogs.MessageDialog.openError()

Answer 1

See How to Make Dialogs.

You can use:

JOptionPane.showMessageDialog(frame, "Eggs are not supposed to be green."); 

And you can also change the symbol to an error message or an warning. E.g see JOptionPane Features.

Answer 2

import javax.swing.JFrame; import javax.swing.JOptionPane;  public class ErrorDialog {    public static void main(String argv[]) {     String message = "\"The Comedy of Errors\"\n"         + "is considered by many scholars to be\n"         + "the first play Shakespeare wrote";     JOptionPane.showMessageDialog(new JFrame(), message, "Dialog",         JOptionPane.ERROR_MESSAGE);   } }