How to Close a Window in Java

Step-by-Step Guide

1. 1

   Step 1: Obtain an instance of a JFrame

   Default close operation is set using the setter method inside the JFrame class setDefaultCloseOperation that determines what happens when the close button is clicked and takes the following parameters:
   WindowConstants.EXIT_ON_CLOSE
   - Closes the frame and terminates the execution of the program.
   
   WindowConstants.DISPOSE_ON_CLOSE
   - Closes the frame and does not necessarily terminate the execution of the program.
   
   WindowConstants.HIDE_ON_CLOSE
   - Makes the frame appear like it closed by setting its visibility property to false.
   
   The difference between HIDE_ON_CLOSE and DISPOSE_ON_CLOSE is that the latter releases all of the resources used by the frame and its components.
   
   WindowConstants.DO_NOTHING_ON_CLOSE
   - Does nothing when the close button is pressed.
   
   Useful if you wish to, for example, display a confirmation dialog before the window is closed.
   
   You can do that by adding a WindowListener to the frame and overriding windowClosing method.
   
   Example of the custom close operation: frame.setDefaultCloseOperation(WindowConstants.DO_NOTHING_ON_CLOSE); frame.addWindowListener(new WindowAdapter() { @Override public void windowClosing(WindowEvent e) { // Ask for confirmation before terminating the program. int option = JOptionPane.showConfirmDialog( frame, "Are you sure you want to close the application?"
   
   "Close Confirmation"
   
   JOptionPane.YES_NO_OPTION, JOptionPane.QUESTION_MESSAGE); if (option == JOptionPane.YES_OPTION) { System.exit(0); } } });
2. 2

   Step 2: or create a new one.

3. 3

   Step 3: Set default close operation.

Detailed Guide

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