windowClosing() and throwing exceptions

Question

I'm trying to save information (a vector to a file) before the window (and script) is closed. I have check and search everywhere I can't find what to do.

The Error I'm having is

unreported exception java.lang.exception; must be caught or declare to be thrown savePlayers().

However I'm using loadPlayers which do the opposite and I don't have any problem with Exceptions. Help anyone please? The code is:

static public void savePlayers() throws Exception
{
    //serialize the List    
        try 
        {
        FileOutputStream file = new FileOutputStream(FILE_NAME);
            ObjectOutputStream output = new ObjectOutputStream(file);
            output.writeObject(players);
            output.close();
        }  
        catch(IOException ex)
        {
            System.out.println (ex.toString());
        }
}



public static void main (String[] args) throws Exception
{    
    JFrame frame = new JFrame("Teams");
    frame.setSize(700,500);
    frame.setLocationRelativeTo(null);
    frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
    frame.addWindowListener(new WindowAdapter(){
        @Override
        public void windowClosing(WindowEvent e)
        {
            try
            {
                savePlayers();
            }
            catch (IOException ex) {
                 ex.printStackTrace();              
            }
            System.exit(0);
        }
    });

Answer 1

The issue is with your these lines of code in main method

try
{
   savePlayers();
}
catch (IOException ex) {
   ex.printStackTrace();              
}

Change it to catch

try
{
   savePlayers();
}
catch (Exception ex) {
   ex.printStackTrace();              
}

It will work. Your savePlayers() method throws Exception not IOException.

The above will fix the issue but I don't know why your savePlayers() method have this strange throws Exception in method definition? You should think to remove it, as your code not throwing any exception. If it is, handle it along with your IOException.

Answer 2

Change the savePlayers method to:

static public void savePlayers() 

Or, change the window listener action to:

@Override
    public void windowClosing(WindowEvent e)
    {
        try
        {
            savePlayers();
        }
        catch (Exception ex) {
             ex.printStackTrace();              
        }
        System.exit(0);
    }

The first option is better because you actually do not need to throw Exception in the savePlayers()