GUI isn't shown while thread is in procces in JAVA

Question

I'm making simple game with very simple thread (1 sec delay) got problem with the thread, I have while(true) loop with the code:

try {
    while (true) {
       Ltimer.setText(getTimeElapsed());
       Thread.currentThread();
       Thread.sleep(1000); // Thread sleeping for 1 second           
    }
} catch (Exception e) {
    JOptionPane.showMessageDialog(null, "error with timer");       
} 

it simply get string every second and updates label text when I'm trying to run it the gui freeze and I can only see the label in a black background, all buttons and bg img dissappeared. tried to fix with setVisible() repaint() but got nothing..

any other options?

Answer 1

don' use Thread#sleep(int) during EDT, then you have issue with Concurency in Swing, if you need to delay any action use java.swing.Timer, example for EDT lack here

Answer 2

My guess is you are using the GUI Event Thread to do this. When you have the GUI thread tied up doing something else it cannot also be updating the screen. I suggest you run a new thread to do this.