final JasperViewer jv = new JasperViewer(jasperPrint, false);
// add window listener to the viewe.
jv.addWindowListener(new java.awt.event.WindowAdapter() {
public void windowClosing(java.awt.event.WindowEvent evt) {
javax.swing.JOptionPane.showMessageDialog(new javax.swing.JFrame(), "I've been closed!!!", "Why?", JOptionPane.INFORMATION_MESSAGE);
}
});
// now show the viewer
jv.show();