I\'ve recently started learning and exploring the basics of GUI programming in Java.
Having been programming for a while I have only done backend work or work and as
EventDispatchThread (EDT) is special thread reserved only for Swing GUI and *Swing's related events e.g. create/change/update Swing JComponents, more for asked questions here and here
all output to the GUI from BackGround Tasks, Runnable#Thread must be wrapped into invokeLater(), from synchronized Objects into invokeAndWait();