CODEWITHSUNDEEP
javaswingwindowlistener
Berlin Brown
Berlin Brown

Reputation: 11734

Basic Java Swing, how to exit and dispose of your application/JFrame

What is a good way to dispose of a JFrame with code like this? I want to handle the Window exit and window close.

I know we shouldn't use System.exit(); 

public class JavaCellularAutomataSquare {

  public static final String TITLE = "Cellular Automata - Squaring Example";

  private int maxWidth = 600;
  private int maxHeight = 600;

  public void launch() {    
    final JFrame frame = new JFrame(TITLE);   
    frame.setLocation(20, 20);    
    frame.setPreferredSize(new Dimension(maxWidth, maxHeight));
    frame.setResizable(false);
    frame.setFocusable(true);

    final JPanel panel = new JPanel();
    panel.setLocation(20, 20);
    panel.setVisible(true);
    panel.setPreferredSize(new Dimension(maxWidth, maxHeight));    
    panel.setFocusable(true);
    panel.setBackground(Color.white);

    // Panel setup, toggle visibility on frame
    frame.add(panel);
    frame.pack();
    frame.setVisible(true);    
  }

}

Upvotes: 10

Views: 28189

Answers (4)

mKorbel
mKorbel

Reputation: 109813

import javax.swing.*;
import java.awt.*;
import java.awt.event.*;

public class ClosingFrame extends JFrame {

    private JMenuBar MenuBar = new JMenuBar();
    private JFrame frame = new JFrame();
    private static final long serialVersionUID = 1L;
    private JMenu File = new JMenu("File");
    private JMenuItem Exit = new JMenuItem("Exit");

    public ClosingFrame() {
        File.add(Exit);
        MenuBar.add(File);
        Exit.addActionListener(new ExitListener());
        WindowListener exitListener = new WindowAdapter() {

            @Override
            public void windowClosing(WindowEvent e) {
                int confirm = JOptionPane.showOptionDialog(frame,
                        "Are You Sure to Close this Application?",
                        "Exit Confirmation", JOptionPane.YES_NO_OPTION,
                        JOptionPane.QUESTION_MESSAGE, null, null, null);
                if (confirm == JOptionPane.YES_OPTION) {
                    System.exit(0);
                }
            }
        };
        frame.addWindowListener(exitListener);
        frame.setDefaultCloseOperation(EXIT_ON_CLOSE);
        frame.setJMenuBar(MenuBar);
        frame.setPreferredSize(new Dimension(400, 300));
        frame.setLocation(100, 100);
        frame.pack();
        frame.setVisible(true);
    }

    private class ExitListener implements ActionListener {

        @Override
        public void actionPerformed(ActionEvent e) {
            int confirm = JOptionPane.showOptionDialog(frame,
                    "Are You Sure to Close this Application?",
                    "Exit Confirmation", JOptionPane.YES_NO_OPTION,
                    JOptionPane.QUESTION_MESSAGE, null, null, null);
            if (confirm == JOptionPane.YES_OPTION) {
                System.exit(0);
            }
        }
    }

    public static void main(String[] args) {
        SwingUtilities.invokeLater(new Runnable() {

            @Override
            public void run() {
                ClosingFrame cf = new ClosingFrame();
            }
        });
    }
}

Upvotes: 10

Heisenbug
Heisenbug

Reputation: 39164

If you need to perform some operations while closing your application, propably you need a shut down hook. Have a look at this post.

Upvotes: 3

Feanor
Feanor

Reputation: 2725

JFrame.setDefaultCloseOperation(DISPOSE_ON_CLOSE) frees up resources when the window is closed. You can see some of the other operations in the Java tutorials here.

The possible arguments that you can use in the method are defined in the WindowConstants interface, if you are curious about your options.

Upvotes: 8

Serabe
Serabe

Reputation: 3924

frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);

JFrame.setDefaultCloseOperation(int operation)

JFrame.EXIT_ON_CLOSE

Upvotes: 1

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