Question

My program will alert users when data (stock name & price) in the database matches with the data (stock name and price) from Yahoo Finance. With the help of HarryJoy i’m able to implement a pop up notification.

The problem now is, all the functions only works on the last frame (YHOO). It will not dispose() after 5 seconds, or when I click the closeButton. Thanks!

    if (stockPriceDB == popStockValue)
    {                       

        String header = "Stock: "  + stock.getTicker() + " is now @ " +  stock.getPrice();          
        String message = "";

        popUpFrame = new JFrame();
        popUpFrame.setSize(320,90); 
        popUpFrame.setUndecorated(true);                                    
        popUpFrame.getContentPane().setLayout(new GridBagLayout());

        GridBagConstraints constraints = new GridBagConstraints();
        constraints.gridx = 0;
        constraints.gridy = 0;
        constraints.weightx = 1.0f;
        constraints.weighty = 1.0f;
        constraints.insets = new Insets(5, 5, 5, 5);
        constraints.fill = GridBagConstraints.BOTH;
        JLabel headingLabel = new JLabel(header);

        ImageIcon headingIcon = new ImageIcon("images/alert.gif");          
        headingLabel.setIcon(headingIcon);          

        popUpFrame.getContentPane().add(headingLabel, constraints);
        constraints.gridx++;
        constraints.weightx = 0f;
        constraints.weighty = 0f;
        constraints.fill = GridBagConstraints.NONE;
        constraints.anchor = GridBagConstraints.NORTH;                          

        closeButton = new JButton(); 

        closeButton = new JButton(new AbstractAction("x") 
        {
        private static final long serialVersionUID = 1L;

        public void actionPerformed(final ActionEvent e) 
            {
                popUpFrame.dispose();
            }
        });

        closeButton.setMargin(new Insets(1, 4, 1, 4));
        closeButton.setFocusable(false);
        popUpFrame.getContentPane().add(closeButton, constraints);
        constraints.gridx = 0;
        constraints.gridy++;
        constraints.weightx = 1.0f;
        constraints.weighty = 1.0f;
        constraints.insets = new Insets(5, 5, 5, 5);
        constraints.fill = GridBagConstraints.BOTH;                 

        JLabel messageLabel = new JLabel(message);  
        popUpFrame.getContentPane().add(messageLabel, constraints);
        popUpFrame.setDefaultCloseOperation(WindowConstants.EXIT_ON_CLOSE);
        popUpFrame.setVisible(true);

        Dimension screenSize = Toolkit.getDefaultToolkit().getScreenSize();
        Insets toolHeight = Toolkit.getDefaultToolkit().getScreenInsets(popUpFrame.getGraphicsConfiguration());
        popUpFrame.setLocation(screenSize.width - popUpFrame.getWidth(), screenSize.height - toolHeight.bottom - (popUpFrame.getHeight() * (x+1)));

        new Thread()
        {                           
        public void run() 
            {
                try 
                {
                    Thread.sleep(5000); 
                    popUpFrame.dispose(); 
                } 
                catch (InterruptedException e) 
                {
                    e.printStackTrace();
                }
            };

        }.start();
    }
}

Answer 1

I suspect that the problem you are getting is that you are passing, to an external code (a different thread in this case), a variable of popUpFrame which you then assign new object every instance of the loop.

This approach is susceptible to errors as you are loosing the reference you passed. Because you are overwriting it every time you create a new object.
Therefore, I think you might be only able to close to latest one.

To avoid something like this a variable you pass to an external code should always be final or when instantiating an external process store a reference to it inside the external code.