如何判断当前线程是否是事件调度thead

Question

I am doing some development by Swing and I am not an expert in it. I only know that:

1, almost all operations on the GUI component should be done in the event dispatcher thread by run code by EventQueue.invokeLater() or EventQueue.invokeAndWait().

2, if there is a time-consuming task, I should put it in another thread rather than the event dispatcher thread to avoid the GUI does not respond to the user.

3, cannot call invokeAndWait from the event dispatcher thread.

So, I wish to arrange some code that may be invoked both by "another" thead or the event dispatcher thread like below:

Runnabe rn = ...;
if (itIsTheEventDispatcherThread) {
    rn.run();
} else {
    EventQueue.invokeAndWait(rn);
}

So, how to judge if the current thread is the event dispatching thread? And, is my strategy appropriate? Thanks a lot!

Answer 1

Use javax.swing.SwingUtilities.isEventDispatchThread()
or java awt.EventQueue.isDispatchThread() (as already using EventQueue )

From documentation of SwingUtilities ¹

Returns true if the current thread is an AWT event dispatching thread.

As of 1.3 this method is just a cover for java.awt.EventQueue.isDispatchThread().

^{1 : I prefer SwingUtilities over EventQueue even for invokeLater (at least when using Swing)}