JFrame应该在什么时候关闭

Question

This code segment is called upon in the making of the JFrame, and when it reaches the dispose() line it does not close. I know it is getting into that block because the other JFrame does open, the only problem is that it is not closing. Anybody know why?

    public LogIn(String title)
{
    super(title);
    checker = new Open("");
    deserializeOpen();
    setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
    setSize(300, 300);
    getContentPane().setLayout(new BorderLayout());
    getContentPane().setBackground(Color.orange);
    Login = new JButton("Login");
    Create = new JButton("New Profile");
    Login.addActionListener(this);
    Create.addActionListener(this);
    buttons = new JPanel();
    buttons.setBackground(Color.orange);
    buttons.setLayout(new GridLayout(0,2));
    buttons.add(Login);
    buttons.add(Create);
    Title = new JLabel("Scrambler");
    Title.setFont(new Font("Times New Roman", Font.BOLD, 24));
    Name = new JTextField(4);
    name = new JLabel("Name:");
    password = new JPasswordField(4);
    pass = new JLabel("Password:");
    Text = new JPanel();
    Text.setLayout(new GridLayout(6,0));
    Text.setBackground(Color.orange);
    Text.add(Title);
    Text.add(name);
    Text.add(Name);
    Text.add(pass);
    Text.add(password);
    getContentPane().add(Text, BorderLayout.CENTER);
    getContentPane().add(buttons, BorderLayout.SOUTH);
    show();
}
    public void deserializeOpen()
{
    try
    {
        FileInputStream door = null;
        try
        {
            door = new FileInputStream("Check.ser");
        }
        catch (FileNotFoundException e)
        {
            new Activator();
            dispose();
        }
        if(door!=null)
        {
         ObjectInputStream reader = new ObjectInputStream(door);
         checker = (Open) reader.readObject();
        }
    }
    catch (IOException e){e.printStackTrace();}
    catch (ClassNotFoundException e){e.printStackTrace();}          
}

these are just two segments of the code, the body is the first part and the deserialize one is the one that is causing the problem

I'm pretty sure that the dispose() line is being reached because I just put a System.out.print() right about and below the dispose() and both printed out

Answer 1

In the constructor of your JFrame subclass, you call deserializeOpen() first, which disposes the frame (no effect since it's not shown yet), and then call show() which opens the frame. So you may have intended to open-close , but instead your code close-opens .

By the way: the show() method is deprecated since JDK1.5, you should use setVisible(true) instead. I'd recommend that you propagate the exceptions in deserializeOpen() and catch them outside, that way you can decide whether or not to open the frame instead of opening and closing it:

public void deserializeOpen() throws Exception { ... }

in the constructor:

try {
  deserializeOpen();
  setVisible(true);
} catch(Exception e) {
  e.printStacktrace(); // or any other error handling
}