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

public class MouseDemo extends JFrame {
private static final long serialVersionUID = 1L;

boolean IS_MAXIMIZED = false;

public MouseDemo() {
super("DoubleClick Demo");
this.addMouseListener(new MouseAdapter() {
public void mouseClicked(MouseEvent e) {
if (e.getClickCount() == 2) {
if (IS_MAXIMIZED) {
setExtendedState(JFrame.NORMAL);
IS_MAXIMIZED = false;
} else {
setExtendedState(JFrame.MAXIMIZED_BOTH);
IS_MAXIMIZED = true;
}
}
}
});

this.setSize(new Dimension(200, 150));
this.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
}

public static void main(String args[]) {
new MouseDemo().setVisible(true);
}
}