Writing to a File Within an ActionListener

[Zake Bake]

So, when I press a certain button, my file is supposed to "safely" update. The code I have for that is:

public void writeBallot() throws IOException{
		
		
		//need to make a new file
		
		File realfile = new File("Ballots.txt");
		
		File tempfile = new File("ballottemp.txt");
		
		tempfile.createNewFile();
		
		PrintWriter p = new PrintWriter(tempfile);
				
		for ( int i = 0 ; i<theButtons.length; i ++)
			p.println(indivelection.get(i) + ":" + intcounts[i]);
		
		realfile.delete();
		
		tempfile.renameTo(realfile);

And when I hit a JButton is when this file needs to be updated. The code for the ActionListener is here:

if(e.getSource()==castVoteButton){
				
			 	int reply = JOptionPane.showConfirmDialog(null,
			 	   "Are you sure you are done voting?",
			 	   "Are You Sure?",
			 	   JOptionPane.YES_NO_OPTION);
				
				if (reply == JOptionPane.YES_OPTION){
					for (int j = 0; j<thePanels.length; j++){
					((Ballot) thePanels[j]).buttonStatus(false);
					((Ballot)thePanels[j]).checkyocolors();
					}
					castVoteButton.setEnabled(false);
					loginButton.setEnabled(true);
					
					for (int p = 0; p<thePanels.length; p++)
						try {
							((Ballot)thePanels[p]).writeBallot();
						} catch (IOException e1) {
							// TODO Auto-generated catch block
							e1.printStackTrace();
						}

Now, I have tested my method to write update the file in another class and it seems to work, but once I wrap it in the try, catch, which is apparently required for the ActionListener, it doesn't seem to do anything.

Does anyone have any suggestions or hints so that I can implement my method when the JButton is pressed?

[Steve Luke]

Do you run the application from the command line or look at a console where errors may be visible? The most likely problem is an exception is happening, but you need to be able to view the error.

[Zake Bake]

As far as the console suggests, there are no exceptions occurring.

[Steve Luke]

Then there is not enough information provided. Create an SSCCE (<= link). Make sure it shows only what is required to reproduce the problem, is small enough so we don't have to trudge through tons of code to help you, and can be compiled and run so we can see the issue.

[Campbell Ritchie]

That looks like too much code for an ActionListener. It also looks as though you have a book which teaches that abomination against object‑oriented programming, addActionListener(this);
I suggest once you have got the method working from the command line, using a call like this, you create a Listener class

public class FileWritingDemo
{
/**
 * Method written only to try out the file writing. Don't use for any real purpose.
 *@deprecated Only for testing use
 */
   @Deprecated public static void main(String[] args)
   {
      . . .
      try
      {
         myApp.writeBallot(file, tempFile, data);
      }
      catch (IOException ioe)
      {
        . . .
      }
   }
}

Note:-

1: I don’t like main methods more than 1 statement long, but I shall make an exception and deprecate the method from further use.

2: I have assumed you are overloading your method so you pass the details of the files, data to write, etc as arguments.

3: You would do well to try out things like file choosers for finding files before writing the Listener.

4: There are several ways to write Listener classes, which you can find about by searching in our GUIs forum. This is a rough‑and‑ready example of one way to do it.

public class FileWriterListener implements ActionListener
{
   private Application myApp;

   public FileWriterListener(Application myApp)
   {
      this.myApp = myApp;
   }
/*
 * Bit about how you get the info into the myApp object omitted
 * You will have to work that out for yourself. It is easier with an
 * anonymous class or a private inner class because they can 
 * often use the fields of their surrounding class directly.
 */
   public void actionPerformed(ActionEvent e)
   {
      myApp.writeBallot(file, tempFile, data);
   }
}

I can try duplicating this thread into the GUIs forum; that might get you more attention.

[Winston Gutkowski]

Zake Bake wrote:Does anyone have any suggestions or hints...

Yes: Don't put extremely long lines in your code.
For one thing, it's bad practise; and here specifically, it screws up the windowing and makes your thread hard to read. I've broken yours up this time, but please re-read the UseCodeTags (←click) page thoroughly.

Thanks.

Winston