windowClosing接口例

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

public class WinCloseTest extends JFrame {
    public WinCloseTest(){
        setTitle("WinCloseTest");
        setSize(400,300);
        addWindowListener(new MyWinListener());
        setVisible(true);
    }
    public static void main(String[] args){
        new WinCloseTest();
    }
}
class MyWinListener extends WindowAdapter{
    public void windowClosing(WindowEvent e) {
        int ret = JOptionPane.showConfirmDialog(null, 
                "确认退出吗？", "确认", JOptionPane.YES_NO_OPTION);
        System.out.println(ret);
        if (ret==JOptionPane.YES_OPTION)
            System.exit(0);
    }
}