JFrame要么不会出现，要么只是一行或无法关闭

Question

我正在写一个游戏，当我与计算机发生碰撞并按E时，它应该打开一个带有问题的小JFrame。但有时框架会打开但右键单击它时无法看到或关闭。或者它只显示一条小线，而不是更像这样：http://postimg.org/image/7upz61cjl。

有源代码：

public class Computer() extends AbstractActor {

     public Computer() throws IOException {
            super("computer", 0, 0, 80, 48, 100, "resources/sprites/computer.png"); 
            question = new JLabel();
            input = new JTextField();
            confirm = new Button("Confirm");

        getQuestion(new InputStreamReader(new DataInputStream(new FileInputStream("resources/questions.txt"))));

        confirm.addActionListener(new ActionListener() {
            public void actionPerformed(ActionEvent e) {
                if (input.getText().equals(password) && net != null) {
                    getWorld().removeActor(net);
                }
                window.dispose();
                window = null;
            }
        });

    }

    public void use(Ripley ripley) {
        if (window == null && !(input.getText().equals(password))) {
            window = new JFrame("Answer this to shut lasers.");
            window.setLayout(new BoxLayout(window.getContentPane(), BoxLayout.Y_AXIS));

            window.add(question);
            window.add(input);
            window.add(confirm);

            window.setDefaultCloseOperation(JFrame.DISPOSE_ON_CLOSE);
            window.setVisible(true);
            window.setResizable(false);
            window.setAlwaysOnTop(true);
            window.pack();
            window.setLocationRelativeTo(null);

            window.addWindowListener(new WindowAdapter() {
                public void windowClosing(WindowEvent e) {
                    window = null;
                }
            });
        }
    }

    public void act() {
        if (net == null) {
            net = (LaserNet)getActorByName("laser net");
        }
    }

    public void getQuestion(InputStreamReader file) throws IOException {
        Random rand = new Random();
        int num = -1;
        while (num % 2 != 0)
            num = rand.nextInt(10);
        try (BufferedReader br = new BufferedReader(file)) {
            String line;
            int i = 0;
            while ((line = br.readLine()) != null) {
                if (i == num) {
                    question.setText(line);
                    line = br.readLine();
                    password = line;
                }
                i++;
            }
        }
        catch (Exception e) {
            System.err.println("Error: " + e.getMessage());
        }



    }
}