这不是将JLabel附加到JPanel

Question

Why isn't the JLabel timeStamp being added too the JPanel rs_pnl? I want the user to make a search, which is sent to this function. If the user types what time is it, then the function should create a JLabel with the time and add it to rs_pnl. It then returns the panel so it can be used by other classes.

    public class Engine {
        public static JPanel getResults(String input){
            JPanel rs_pnl = new JPanel();
            rs_pnl.setLayout(new BorderLayout());
            rs_pnl.setSize(500, 600);
            String feed = input.toLowerCase();
            String timeLabel = new SimpleDateFormat("hh:mm MM/dd/yy").format(Calendar.getInstance().getTime());
            if(feed.contains("define")){

            }else if(feed.contains("start")){
                //START INDICATED PROGRAM
            }else if(feed.equals("what are the options") | feed.equals("show the menu") | feed.equals("show menu") | feed.equals("options") | feed.equals("menu")){
                JPanel menu = new Menu().show_menu();
                rs_pnl.add(menu, BorderLayout.CENTER);
                System.out.println("Menu Launched");
            }else if(feed.equals("shutdown") | feed.equals("exit")){
                System.exit(0);
            }else if(feed.equals("what time is it") | feed.equals("whats todays date") | feed.equals("what's todays date") | feed.equals("whats the time") | feed.equals("time")){
                JLabel timeStamp  = new JLabel(timeLabel);
                timeStamp.setFont(new Font("Arial", Font.PLAIN, 5));
                timeStamp.setForeground(new Color(69,69,69));
                rs_pnl.add(timeStamp, BorderLayout.CENTER);
            }else{
                //INCLUDE CLASS TO DO ONLINE SEARCH
            }
            return rs_pnl;
        }
    }

Answer 1

By default Swing component have a default size of (0, 0) so there is nothing to paint.

The basic logic for dynamically add components to a visible GUI is:

panel.add(..._);
panel.revalidate(); // to invoke the layout manager
panel.repaint(); // to paint all the components