Re: JDialogs launched outside the Event-Dispatch Thread

Lew <>
Fri, 7 May 2010 07:55:11 -0700 (PDT)
Marcin Rodzik wrote:

Being aware of what has been said <>
I'd like to ask explicitly: what should I do if I want to display some
information to the user in a Swing GUI app using a JDialog? I know
dialogs are event-driven so that execution of the thread which
requested displaying the dialog stops, but other currently fired
events are still handled.

The thing I don't know and I'd like to is: should I create a Runnable
object and schedule it for execution:

SwingUtilities.invokeAndWait(new Runnable() {
  public void run() {
    /* display the dialog here */


Usually the JDialog is raised in response to an event already on the
dispatch thread, but using invokeAndWait() or invokeLater() is fine if
you're already on the EDT.

I don't know why you'd prefer invokeAndWait() over invokeLater().


I can simply write the code like this:

JOptionPane.showMessageDialog(parent, msg, title, messageType);

without the SwingUtilities stuff and Swing will handle the code
correctly anyway?

Only if you're already on the EDT to start with, otherwise it's a bad

I used to follow the first option but now I doubt if
it makes any sense.

Depends on whether you really mean for the caller to wait for the


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