public static void main(String[] args) { String propFileName = null; if (args.length > 0) { propFileName = args[0]; } OneBlockOperation application = new OneBlockOperation(propFileName); JFrame frame = new JFrame(); frame.setTitle(application.getClass().getName()); frame.getContentPane().add(application, BorderLayout.CENTER); application.init(); frame.addWindowListener( new WindowAdapter() { public void windowClosing(WindowEvent e) { System.exit(0); } }); frame.setBounds(50, 50, 400, 150); frame.setVisible(true); }