JLabel isn't working properly unless I click window title

Question

I have a program where I am trying to display one image and after 5 seconds it removes the image from the JLabel then displays the 2nd image but the 2nd image won't display by itself unless I click the the header or the bar on top of the window that the program creates. I want to have the image display automatically without me interacting with the window. Any help?

public void pictures(){
  try{
     BufferedImage myPicture = ImageIO.read(new File("round-1.jpg"));
     JLabel picLabel = new JLabel(new ImageIcon(myPicture));
     picLabel.setSize(800,600);
     add(picLabel);
     picLabel.setVisible(true);
     Timer timer = new Timer();
     timer.schedule(new TimerTask() {
          @Override
          public void run(){
             picLabel.setVisible(false);
             pictures2();
          }
       }, 5000);
     }
  catch(IOException e){
     e.printStackTrace();
  }
}

public void pictures2(){
  try{
     BufferedImage myPicture2 = ImageIO.read(new File("go.png"));
     JLabel picLabel2 = new JLabel(new ImageIcon(myPicture2));
     picLabel2.setSize(800,600);
     add(picLabel2);
     picLabel2.setVisible(true);
  }
  catch(IOException e){
     e.printStackTrace();
  }
}

Answer 1

Perhaps it is because the work (run method) for your timer task runs in a separate thread and is not in the Swing event-handling thread?

I suspect you should be calling SwingUtilities.invokeLater in your timer's run method so that the changes to the label are done in the Swing event-handling thread.