@Override public void actionPerformed(ActionEvent e) { try { if (e.getSource() == ok_button) { if (mainFrame != null) { Client client = new Client(serverAddress.getText(), Integer.parseInt(serverPort.getText()), 0); if (client.getClientThread().getClientSocket().isConnected()) mainFrame.setClient(client); } this.setVisible(false); this.dispose(); } else if (e.getSource() == cancel_button) { mainFrame.setClient(null); this.setVisible(false); this.dispose(); } } catch (NumberFormatException exception) { JOptionPane.showMessageDialog(this, "Invalid value: " + exception.getMessage()); } }