As other answers have said, it executes your Runnable on the AWT event-dispatching thread. But why would you want to do that? Because the Swing data structures aren’t thread-safe, so to provide programmers with an easily-achievable way of preventing concurrent access to them, the Swing designers laid down the rule that all code that accesses … Read more
Do I have to use each time I need to update the GUI components? No, not if you’re already on the event dispatch thread (EDT) which is always the case when responding to user initiated events such as clicks and selections. (The actionPerformed methods etc, are always called by the EDT.) If you’re not on … Read more
The event dispatch thread is a special thread that is managed by AWT. Basically, it is a thread that runs in an infinite loop, processing events. The java.awt.EventQueue.invokeLater and javax.swing.SwingUtilities.invokeLater methods are a way to provide code that will run on the event queue. Writing a UI framework that is safe in a multithreading environment … Read more